CN113522023A - System and method for treating VOCs gas in engine tail gas - Google Patents

System and method for treating VOCs gas in engine tail gas Download PDF

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Publication number
CN113522023A
CN113522023A CN202010296602.1A CN202010296602A CN113522023A CN 113522023 A CN113522023 A CN 113522023A CN 202010296602 A CN202010296602 A CN 202010296602A CN 113522023 A CN113522023 A CN 113522023A
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CN
China
Prior art keywords
electric field
anode
cathode
tail gas
vocs
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Pending
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CN202010296602.1A
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Chinese (zh)
Inventor
唐万福
赵晓云
王大祥
段志军
邹永安
奚勇
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Shanghai Bixiufu Enterprise Management Co Ltd
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Shanghai Bixiufu Enterprise Management Co Ltd
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Application filed by Shanghai Bixiufu Enterprise Management Co Ltd filed Critical Shanghai Bixiufu Enterprise Management Co Ltd
Priority to CN202010296602.1A priority Critical patent/CN113522023A/en
Priority to PCT/CN2020/086856 priority patent/WO2020216361A1/en
Priority to CN202080030932.4A priority patent/CN113748258A/en
Priority to PCT/CN2020/086863 priority patent/WO2020216367A1/en
Priority to CN202080030898.0A priority patent/CN113727781A/en
Priority to CN202080030900.4A priority patent/CN113710881A/en
Priority to CN202090000500.4U priority patent/CN216974977U/en
Priority to CN202080030946.6A priority patent/CN113748259A/en
Priority to PCT/CN2020/086864 priority patent/WO2020216368A1/en
Priority to PCT/CN2020/086865 priority patent/WO2020216369A1/en
Priority to PCT/CN2020/086866 priority patent/WO2020216370A1/en
Priority to PCT/CN2020/086858 priority patent/WO2020216363A1/en
Priority to CN202090000499.5U priority patent/CN218235209U/en
Priority to PCT/CN2020/086857 priority patent/WO2020216362A1/en
Priority to CN202080030940.9A priority patent/CN113747976A/en
Priority to CN202080030899.5A priority patent/CN113710350A/en
Priority to PCT/CN2020/086861 priority patent/WO2020216365A1/en
Priority to PCT/CN2020/086862 priority patent/WO2020216366A1/en
Priority to PCT/CN2020/086860 priority patent/WO2020216364A1/en
Priority to CN202080030938.1A priority patent/CN113710366A/en
Publication of CN113522023A publication Critical patent/CN113522023A/en
Pending legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/007—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by irradiation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/02—Plant or installations having external electricity supply
    • B03C3/04—Plant or installations having external electricity supply dry type
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/34—Constructional details or accessories or operation thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/01—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust by means of electric or electrostatic separators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
    • F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2086—Activating the catalyst by light, photo-catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
    • B01D2257/708—Volatile organic compounds V.O.C.'s
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2259/00—Type of treatment
    • B01D2259/80—Employing electric, magnetic, electromagnetic or wave energy, or particle radiation
    • B01D2259/804—UV light

Abstract

The invention provides a system and a method for treating VOCs gas in engine tail gas, wherein the system for treating the VOCs gas in the engine tail gas comprises the following steps: an inlet, an outlet, and a flow channel between the inlet and the outlet; the device comprises an inlet, an outlet and a flow channel, and is characterized by further comprising an ultraviolet device and a tail gas electric field device, wherein the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet. The tail gas electric field device includes: the electric field device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field. The invention utilizes the electric field to remove dust, and effectively removes the nanoparticles in the engine tail gas and the product of the engine tail gas treated gas by UV irradiation.

Description

System and method for treating VOCs gas in engine tail gas
Technical Field
The invention belongs to the field of environmental protection, and relates to a system and a method for treating VOCs gas in engine tail gas.
Background
The pollution of the engine to the environment mainly comes from engine exhaust gas which is an exhaust product of the engine, and the engine exhaust gas contains a large amount of Volatile Organic Compounds (VOCs), carbon monoxide (CO) and Nitrogen Oxides (NO)x) And the like, which causes serious pollution to the environment. In particular, the VOCs contained in the engine exhaust gas mainly include hydrocarbons (alkanes, aromatics, olefins), and derivatives of hydrocarbons (halogenated hydrocarbons, aldehydes, ketones, alcohols, N/S atom-containing structures), and the like. VOCs can directly harm human bodies and influence human health conditions, and not only have stimulating effect on organs of systems such as human vision, smell, respiration and the like, but also have damage to organs such as heart, lung and the like and nervous systems. In addition, VOCs can react with other pollutants in the atmospheric environment, leading to local or global environmental problems, such as in sunlight (ultraviolet light), VOCs can react with NOx photochemically to form fine suspended particulate matter and photochemical smog, which can harm health and crop yield reduction.
In view of the fact that the sources of VOCs are more, the discharge amount is increased year by year, and the composition structure of VOCs is very complex, and developing a method for effectively reducing the discharge amount of VOCs is always a hotspot and a difficulty of industrial research. The discharge amount of VOCs in the atmosphere is reduced, and the discharge source can be controlled or the tail end of the discharge can be comprehensively treated.
For high concentrations of VOCs (greater than 5000 mg/m)3) The method is suitable for recycling, and comprises an adsorption method, an absorption method, a membrane separation method and the like, wherein the physical adsorption method is only to convert VOCs from a gaseous form into an adsorption state, the organic matters of the VOCs in the adsorption state need further treatment, and the adsorbent needs to be subjected to repeated regeneration processes.
The medium and low concentration VOCs are usually controlled by molecular degradation technology, mainly including catalytic combustion method, photocatalytic method, low temperature plasma method, photodecomposition method, photocatalytic oxidation method, etc. Among them, the catalytic combustion technology is limited by the high price of metal catalysts, excessive energy consumption, catalyst poisoning and deactivation, and the flammable and explosive properties of VOCs at high temperatures. The photocatalytic oxidation technology is a method capable of realizing the decomposition of low-concentration VOCs at room temperature, is considered as a promising treatment process, but is also limited by the inactivation of the catalyst, the regeneration of holes by electrons and the like, and meanwhile, the photocatalytic oxidation technology can achieve higher VOCs removal efficiency at the beginning of the reaction, but photocatalytic oxidation intermediate deposits are formed on the surface of the photocatalyst in the reaction process, so that the catalytic activity of the photocatalyst is reduced.
The technology of Ultraviolet (UV) degradation of VOCs is a simple method for eliminating VOCs, and meanwhile, the UV degradation technology does not use a catalyst, so that the cost and operability are low, and the attention of the industry is attracted. There are two reaction pathways for UV light degradation of VOCs: one reaction path is photolysis, also called photodissociation, where the typical technology is UV lamp, because the photon energy of short wavelength UV is higher than the bond energy of the chemical bonds inside most of the pollutant molecules, the 185nm wavelength UV light emitted by UV lamp has higher energy (6.7eV), which can be used to destroy and decompose the chemical bond structure of various VOCs, including the more difficult-to-process organic molecular structures such as benzene, toluene, xylene, etc.; another reaction pathway is photooxidation, ultraviolet light of 185nm wavelength, which generates high-energy photons that activate O2And H2O water vapor molecule, generating a large amount of active free radicals with strong oxidizing property, such as O (1D), O (3P), hydroxyl free radical (OH), O3And the like, so that VOCs molecules and newly generated intermediate small molecules can be continuously oxidized and decomposed, and the effect of reducing the concentration of pollutants is achieved.
In practical engineering cases, it is found that in the process of treating VOCs by adopting UV photolysis technology, photodegradation and photopolymerization reaction occur simultaneously, and the photodegradation can generate harmless CO2And H2O, and the production of photopolymerizationThe substance is a high molecular polymer and is expressed as dust particles (organic solid particles with large molecular weight), and the direct discharge can cause secondary pollution to the environment. However, in the existing process route for treating the VOCs by using the photolysis technology, only the concentration change of the VOCs is detected, the particulate product of the polymerization reaction is not considered, the particulate is used as a product of the photolysis technology, and if the particulate is not trapped and collected, the particulate is discharged into the atmosphere, so that the dust harm to the environment is caused.
Electrostatic dust collection is a gas dust collection method, and is generally used for purifying gas or recovering useful dust particles in the industrial fields of metallurgy, chemistry and the like. In the prior art, the engine exhaust particulate matters cannot be treated based on electrostatic dust removal due to the problems of large occupied space, complex system structure, poor dust removal effect (particularly, the problems that large particulate matters can only be removed and the dust removal efficiency is remarkably reduced under the condition that water drops are contained in high-temperature or low-temperature exhaust) and the like.
Disclosure of Invention
In view of the above-mentioned shortcomings of the prior art, the present invention provides a system and a method for treating VOCs in engine exhaust, which are used to solve at least one of the problems of regular maintenance and unstable effect of the prior art engine exhaust treatment system, and also solve the problem that the prior art can not effectively remove VOCs in engine exhaust. The inventor of the application finds new problems in the technology of treating the tail gas containing the VOCs by ultraviolet rays and finds a corresponding technical means to solve the problems. For example, the inventors of the present application have found that the UV-irradiated product of the exhaust gas containing VOCs contains nanoparticles, particularly particles below 50nm, particularly particles around 23nm, and thus it is necessary to remove the nanoparticles before the exhaust gas is discharged into the air. In addition, the present inventors found that the electric field dedusting system invented by them can effectively remove nanoparticles, especially particles below 50nm, from the product after UV treatment of the tail gas containing VOCs, and avoid secondary pollution, thus solving the technical problems not recognized by those skilled in the art and achieving unexpected technical effects. Meanwhile, the inventor of the application discovers new problems in the existing ionization dust removal technology through research and solves the problems through a series of technical means, for example, when the temperature of tail gas or the temperature of an engine is lower than a certain temperature, the tail gas of the engine may contain liquid water; under the high temperature condition, through control tail gas electric field device anodal collection dirt area and the area ratio of discharging of negative pole, the length of negative pole/positive pole, the interpole distance and set up auxiliary electric field etc. effectively reduce electric field coupling to make tail gas electric field device still have efficient collection dirt ability under high temperature impact. Therefore, the invention is suitable for operation under severe conditions, and ensures the removal efficiency of VOCs and the removal efficiency of nano particles in tail gas, so the invention is completely suitable for engines from a commercial perspective.
To achieve the above and other related objects, the present invention provides the following examples:
1. example 1 provided by the present invention: a system for treating VOCs in engine exhaust, comprising:
an inlet, an outlet, and a flow channel between the inlet and the outlet;
the device comprises an inlet, an outlet and a flow channel, and is characterized by further comprising an ultraviolet device and a tail gas electric field device, wherein the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet.
2. Example 2 provided by the invention: including example 1 above, wherein the ultraviolet device comprises at least one ultraviolet lamp.
3. Example 3 provided by the present invention: including the above example 1 or 2, wherein the ultraviolet light provided by the ultraviolet lamp is single-peak ultraviolet light or dual-peak ultraviolet light.
4. Example 4 provided by the present invention: including any of examples 1-3 above, wherein the ultraviolet lamp provides a single peak ultraviolet light having a main peak at 253.7nm or 185 nm.
5. Example 5 provided by the present invention: including any of examples 1-4 above, wherein the ultraviolet lamp provides dual-peak ultraviolet light having dominant peaks of 253.7nm and 185nm, respectively.
6. Example 6 provided by the present invention: the device comprises the above example 1, wherein the tail gas electric field device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, and the electric field cathode and the electric field anode are used for generating a tail gas ionization dust removal electric field.
7. Example 7 provided by the present invention: including example 6 above, wherein the field anode comprises a first anode portion proximate the field device inlet and a second anode portion proximate the field device outlet, at least one cathode support plate disposed between the first anode portion and the second anode portion.
8. Example 8 provided by the invention: including any of examples 1-7 above, wherein the off-gas electric field apparatus further comprises an off-gas insulation mechanism for achieving insulation between the cathode support plate and the electric field anode.
9. Example 9 provided by the present invention: the method includes the above example 8, wherein an electric field flow channel is formed between the electric field anode and the electric field cathode, and the tail gas insulation mechanism is disposed outside the electric field flow channel.
10. Example 10 provided by the invention: including the above example 8 or 9, wherein the exhaust gas insulation mechanism includes an insulation portion and a heat insulation portion; the insulating part is made of ceramic materials or glass materials.
11. Example 11 provided by the present invention: the method includes the above example 10, wherein the insulating part is an umbrella-shaped string ceramic column, an umbrella-shaped string glass column, a column-shaped string ceramic column or a column-shaped glass column, and glaze is hung inside and outside the umbrella or inside and outside the column.
12. Example 12 provided by the present invention: including the above example 11, wherein the distance between the outer edge of the umbrella-shaped string ceramic pillar or the umbrella-shaped string glass pillar and the electric field anode is more than 1.4 times the electric field distance, the sum of the distances between the umbrella-shaped protruding edges of the umbrella-shaped string ceramic pillar or the umbrella-shaped string glass pillar is more than 1.4 times the insulation distance between the umbrella-shaped string ceramic pillar or the umbrella-shaped string glass pillar, and the total depth inside the umbrella edge of the umbrella-shaped string ceramic pillar or the umbrella-shaped string glass pillar is more than 1.4 times the insulation distance between the umbrella-shaped string ceramic pillar or the umbrella-shaped string glass pillar.
13. Example 13 provided by the present invention: including any of examples 7-12 above, wherein a length of the first anode portion is 1/10-1/4, 1/4-1/3, 1/3-1/2, 1/2-2/3, 2/3-3/4, or 3/4-9/10 of the electric field anode length.
14. Example 14 provided by the present invention: including any of examples 7-13 above, wherein the first anode portion is of a length sufficient to remove a portion of the dust, reduce dust accumulation on the exhaust insulation mechanism and the cathode support plate, and reduce electrical breakdown due to the dust.
15. Example 15 provided by the present invention: including any of examples 7-14 above, wherein the second anode portion includes a dust deposition section and a reserved dust deposition section.
16. Example 16 provided by the present invention: including any of examples 6-15 above, wherein the electric field cathode comprises at least one electrode rod.
17. Example 17 provided by the invention: including example 16 above, wherein the electrode rod has a diameter of no greater than 3 mm.
18. Example 18 provided by the present invention: including the above-mentioned example 16 or 17, wherein the electrode rod has a shape of a needle, a polygon, a burr, a screw rod, or a column.
19. Example 19 provided by the present invention: including any of examples 6-18 above, wherein the electric field anode is comprised of a hollow tube bundle.
20. Example 20 provided by the present invention: including example 19 above, wherein the hollow cross section of the electric field anode tube bundle takes a circular or polygonal shape.
21. Example 21 provided by the present invention: including example 20 above, wherein the polygon is a hexagon.
22. Example 22 provided by the present invention: including any of examples 19-21 above, wherein the tube bundle of field anodes is honeycomb shaped.
23. Example 23 provided by the present invention: including any of examples 6-22 above, wherein the electric field cathode is penetrated within the electric field anode.
24. Example 29 provided by the present invention: including any of examples 6-28 above, wherein the electric field anode is 10-90mm long and the electric field cathode is 10-90mm long.
25. Example 30 provided by the present invention: including the above example 29, in which the corresponding dust collecting efficiency was 99.9% when the electric field temperature was 200 ℃.
26. Example 31 provided by the present invention: including the above-mentioned example 29 or 30, wherein the corresponding dust collecting efficiency is 90% when the electric field temperature is 400 ℃.
27. Example 32 provided by the invention: including any one of the above examples 29 to 31, wherein the corresponding dust collection efficiency is 50% when the electric field temperature is 500 ℃.
28. Example 33 provided by the present invention: including any one of the above examples 6 to 32, wherein the exhaust gas electric field apparatus further includes an auxiliary electric field unit for generating an auxiliary electric field that is not parallel to the exhaust gas ionization dust removal electric field.
29. Example 34 provided by the invention: including any one of the above examples 6 to 32, wherein the exhaust gas electric field device further includes an auxiliary electric field unit, the exhaust gas ionization dust removal electric field includes a flow channel, and the auxiliary electric field unit is configured to generate an auxiliary electric field that is not perpendicular to the flow channel.
30. Example 35 provided by the invention: including the above example 33 or 34, wherein the auxiliary electric field unit includes a first electrode, and the first electrode of the auxiliary electric field unit is disposed at or near the inlet of the exhaust gas ionization dust removal electric field.
31. Example 36 provided by the invention: example 35 above is included, wherein the first electrode is a cathode.
32. Example 37 provided by the present invention: including the above example 35 or 36, wherein the first electrode of the auxiliary electric field unit is an extension of the electric field cathode.
33. Example 38 provided by the invention: examples 37 above are included, wherein the first electrode of the auxiliary electric field unit has an angle α with the electric field anode, and 0 ° < α ≦ 125 °, or 45 ° ≦ α ≦ 125 °, or 60 ° ≦ α ≦ 100 °, or α ≦ 90 °.
34. Example 39 provided by the invention: including any one of the above examples 33-38, wherein the auxiliary electric field unit includes a second electrode, and the second electrode of the auxiliary electric field unit is disposed at or near an outlet of the exhaust gas ionization dust removal electric field.
35. Example 40 provided by the present invention: including example 39 above, wherein the second electrode is an anode.
36. Example 41 provided by the present invention: including the above examples 39 or 40, wherein the second electrode of the auxiliary electric field unit is an extension of the electric field anode.
37. Example 42 provided by the present invention: examples 41 described above are included, wherein the second electrode of the auxiliary electric field unit has an angle α with the electric field cathode, and 0 ° < α ≦ 125 °, or 45 ° ≦ α ≦ 125 °, or 60 ° ≦ α ≦ 100 °, or α ≦ 90 °.
38. Example 43 provided by the invention: any one of the above examples 33 to 36, 39 and 40 is included, wherein the electrodes of the auxiliary electric field are provided independently of the electrodes of the off-gas ionization dust removal electric field.
39. Example 44 provided by the invention: any one of the above examples 6 to 43 is included, wherein a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode is 1.667: 1-1680: 1.
40. example 45 provided by the invention: any one of the above examples 6 to 43 is included, wherein a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode is 6.67: 1-56.67: 1.
41. example 46 provided by the invention: including any of examples 6-45 above, wherein the electric field cathode has a diameter of 1-3 mm, and the electric field anode has a polar separation from the electric field cathode of 2.5-139.9 mm; the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is 1.667: 1-1680: 1
42. Example 47 provided by the invention: including any of examples 6-45 above, wherein a polar separation of the electric field anode and the electric field cathode is less than 150 mm.
43. Example 48 provided by the invention: including any one of examples 6-45 above, wherein the inter-polar distance between the electric field anode and the electric field cathode is 2.5-139.9 mm.
44. Example 49 provided by the invention: including any one of examples 6-45 above, wherein the electric field anode is separated from the electric field cathode by a distance of 5-100 mm.
45. Example 50 provided by the invention: including any of examples 6-49 above, wherein the electric field anode is 10-180mm in length.
46. Example 51 provided by the present invention: including any of examples 6-49 above, wherein the electric field anode is 60-180mm in length.
47. Example 52 provided by the invention: including any of examples 6-51 above, wherein the electric field cathode has a length of 30-180 mm.
48. Example 53 provided by the present invention: including any of examples 6-51 above, wherein the electric field cathode length is 54-176 mm.
49. Example 54 provided by the invention: including any one of examples 44-53 above, wherein, when operating, the number of couplings of the exhaust gas ionization dust removal electric field is ≦ 3.
50. Example 55 provided by the invention: including any of examples 33-53 above, wherein, when operating, the number of couplings of the exhaust gas ionization dust removal electric field is ≦ 3.
51. Example 56 provided by the invention: any one of the above examples 6 to 55 is included, wherein the voltage of the tail gas ionization dust removal electric field ranges from 1kv to 50 kv.
52. Example 57 provided by the invention: including any of examples 6-56 above, wherein the exhaust gas electric field apparatus further comprises a plurality of connection housings through which the series electric field stages are connected.
53. Example 58 provided by the invention: including example 57 above, where the distance of adjacent electric field levels is greater than 1.4 times the pole pitch.
54. Example 105 provided by the invention: including any of the above examples 1 to 58, further comprising a water removal device for removing liquid water prior to the electric field device inlet.
55. Example 106 provided by the invention: including example 105 above, where the water removal device removes liquid water from the exhaust gas when the exhaust gas temperature or the engine temperature is below a certain temperature.
56. Example 107 provided by the invention: the above example 106 is included, wherein the certain temperature is 90 ℃ or more and 100 ℃ or less.
57. Example 108 provided by the invention: the above example 106 is included, wherein the certain temperature is 80 ℃ or higher and 90 ℃ or lower.
58. Example 109 provided by the invention: including example 106 above, wherein the certain temperature is 80 ℃ or less.
59. Example 111 provided by the invention: including any of examples 1-110 above, further comprising an exhaust gas temperature reduction device for reducing the temperature of the exhaust gas prior to the inlet of the electric field device.
60. Example 112 provided by the invention: including above-mentioned example 111, wherein, the tail gas heat sink includes heat exchange unit for carrying out the heat exchange with the tail gas of engine to heat the heat transfer medium of liquid in heat exchange unit into gaseous heat transfer medium.
61. Example 113 provided by the invention: including example 112 above, wherein the heat exchange unit comprises:
the tail gas passing cavity is communicated with an exhaust pipeline of the engine and is used for the tail gas of the engine to pass through;
the medium gasification cavity is used for converting the liquid heat exchange medium and the tail gas into a gaseous state after heat exchange.
62. Example 114 provided by the invention: including any one of examples 112-113 above, wherein the exhaust gas cooling device further includes a heat preservation pipeline connected between the exhaust pipeline of the engine and the heat exchange unit.
63. Example 115 provided by the invention: including any of examples 111-114 above, wherein the exhaust gas cooling device includes a fan that cools the exhaust gas before the fan passes air into the electric field device inlet.
64. Example 116 provided by the invention: including example 115 above, wherein the air is 50% to 300% of the tail gas.
65. Example 117 provided by the invention: including example 115 above, wherein the air is 100% to 180% of the tail gas.
66. Example 118 provided by the invention: including example 115 above, wherein the air is introduced at 120% to 150% of the tail gas.
67. Example 119 provided by the invention: any of the above examples 1-118 is included, wherein an engine is also included.
68. Example 120 provided by the invention: including any one of the above examples 1-119, wherein the system for treating VOCs in engine exhaust further comprises an adsorption device disposed between the ultraviolet device and the electric field device.
69. Example 76 provided by the invention: including example 74 above, wherein the adsorbent material is disposed within the adsorbent device.
70. Example 77 provided by the invention: including example 76 above, wherein the adsorbent material comprises at least one of activated carbon, molecular sieve.
71. Example 78 provided by the invention: a method for treating VOCs in engine exhaust comprises the following steps:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
and (3) performing electric field dust removal treatment on the product after the engine tail gas is treated by UV, and removing particulate matters in the product after the UV treatment.
72. Example 79 provided by the invention: example 78 is included, wherein the method for treating VOCs in engine exhaust further includes subjecting the UV-treated products to an adsorption treatment before the electric field dust removal treatment.
73. Example 80 provided by the invention: example 79 is included, wherein the adsorbent of the adsorption treatment is activated carbon and/or molecular sieve.
74. Example 130 provided by the invention: including any of examples 125-129, wherein the UV treatment employs at least one ultraviolet lamp.
75. Example 131 provided by the invention: including any of the above examples 125-130, wherein the ultraviolet light provided by the ultraviolet lamp is single-peak ultraviolet light or dual-peak ultraviolet light.
76. Example 132 provided by the invention: including any one of the above examples 125-131, wherein the ultraviolet lamp provides a single peak ultraviolet light having a main peak at 253.7nm or 185 nm.
77. Example 133 provided by the invention: including example 125 and 132 above, wherein the ultraviolet lamp provides two-peak ultraviolet light having dominant peaks of 253.7nm and 185nm, respectively.
78. Example 148 provided by the invention: including any one of examples 125-147, the electric field dust removal processing method further includes: a method for reducing electric field coupling in engine tail gas dust removal comprises the following steps:
the electric field anode parameters or/and the electric field cathode parameters are selected to reduce the number of electric field couplings.
79. Example 149 provided by the invention: example 148 is included wherein a ratio of a dust collection area of the electric field anode to a discharge area of the electric field cathode is selected.
80. Example 150 provided by the invention: example 149 is included, wherein selecting a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode to be 1.667: 1-1680: 1.
81. example 151 provided by the invention: example 149 is included, wherein selecting a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode to be 6.67: 1-56.67: 1.
82. example 152 provided by the invention: including any one of examples 148 through 151, wherein the diameter of the electric field cathode is selected to be 1-3 mm, and the inter-polar distance between the electric field anode and the electric field cathode is selected to be 2.5-139.9 mm; the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is 1.667: 1-1680: 1.
83. example 153 provided by the invention: including any one of examples 148 to 152, wherein including selecting a polar separation of the electric field anode and the electric field cathode to be less than 150 mm.
84. Example 154 provided by the invention: including any one of examples 148 to 152, wherein including selecting a polar separation of the electric field anode and the electric field cathode to be 2.5-139.9 mm.
85. Example 155 provided by the invention: including any one of examples 148 to 152, wherein including selecting a polar separation of the electric field anode and the electric field cathode to be 5-100 mm.
86. Example 156 provided by the invention: including any of examples 148 to 155, wherein comprising selecting the electric field anode to be 10-180mm in length.
87. Example 157 provided by the invention: including any of examples 148 to 155, wherein comprising selecting the electric field anode length to be 60-180 mm.
88. Example 158 provided by the invention: including any one of examples 148 to 157, wherein comprising selecting the electric field cathode length to be 30-180 mm.
89. Example 159 provided by the invention: including any one of examples 148 to 157, wherein comprising selecting the electric field cathode length to be 54-176 mm.
90. Example 160 provided by the invention: including any one of examples 148 to 159, wherein the electric field cathode is selected to include at least one electrode rod.
91. Example 161 provided by the invention: examples 160 are included, including selecting the electrode rod to have a diameter of no more than 3 mm.
92. Example 162 provided by the invention: examples 160 or 161 are included, including selecting the shape of the electrode rod to be needle-like, polygonal, burred, threaded rod-like, or cylindrical.
93. Example 163 provided by the invention: including any of examples 148 to 162, wherein comprising selecting the electric field anode to be comprised of a hollow tube bundle.
94. Example 164 provided by the invention: example 163 is included, wherein the cross-section of the void comprising the anode tube bundle is selected to be circular or polygonal.
95. Example 165 provided by the invention: examples 164 are included, wherein selecting the polygon to be a hexagon.
96. Example 166 provided by the invention: including any one of examples 163-165, wherein the tube bundle comprising the electric field anodes is selected to be honeycomb-shaped.
97. Example 167 provided by the invention: including any one of examples 148 to 166, wherein including selecting the electric field cathode to be penetrated within the electric field anode.
98. Example 168 provided by the invention: including any of examples 148 through 167, wherein the electric field anode and/or the electric field cathode dimensions are selected such that the electric field coupling number is ≦ 3.
99. Example 169 provided by the invention: including any one of examples 125 and 168, the electric field dust removal processing method further includes: an engine tail gas dedusting method comprises the following steps: when the temperature of the tail gas is lower than 100 ℃, removing liquid water in the tail gas, and then ionizing and dedusting.
100. Example 170 provided by the invention: example 169 includes that the off-gas is subjected to ionization dust removal when the temperature of the off-gas is equal to or higher than 100 ℃.
101. Example 171 provided by the invention: including example 169 or 170, wherein liquid water is removed from the tail gas at a temperature of less than or equal to 90 ℃, and then ionized for dust removal.
102. Example 172 provided by the invention: including example 169 or 170, wherein liquid water is removed from the tail gas at a temperature of 80 ℃ or less, and then ionized for dust removal.
103. Example 173 provided by the invention: including example 169 or 170, wherein liquid water is removed from the tail gas at a temperature of 70 ℃ or less, and then ionized for dust removal.
104. Example 174 provided by the invention: including example 169 or 170, where the liquid water in the tail gas is removed using an electrocoagulation demisting process followed by ionization for dust removal.
105. Example 105 provided by the invention: including any one of examples 71 to 104, wherein the UV treated exhaust product contains nanoparticles, and wherein the removal of the nanoparticles in the UV treated exhaust product comprises removal of nanoparticles in the UV treated exhaust product.
106. Example 106 provided by the invention: including any of examples 71-105, wherein the UV treated exhaust product contains particulates smaller than 50nm, and wherein removing particulates from the UV treated exhaust product comprises removing particulates smaller than 50nm from the UV treated exhaust product.
107. Example 107 provided by the invention: including any of examples 71-106, wherein the UV treated exhaust product comprises 15-35 nm particulate matter, and wherein removing the particulate matter comprises removing 15-35 nm particulate matter from the UV treated exhaust product.
108. Example 108 provided by the invention: including any one of examples 71-107, wherein the UV treated exhaust product contains 23nm particulate matter, and wherein removing particulate matter from the UV treated exhaust product comprises removing 23nm particulate matter from the UV treated exhaust product.
109. Example 109 provided by the invention: including any one of examples 71 to 108, wherein the removal rate of 23nm particulate matter in the product after the removal of the UV-treated tail gas is greater than or equal to 93%.
110. Example 110 provided by the invention: including any one of examples 71 to 109, wherein the removal rate of 23nm particulate matter in the product after the removal of the UV-treated off-gas is not less than 95%.
111. Example 111 provided by the invention: including any one of examples 71 to 110, wherein the removal rate of 23nm particulate matter in the product after the removal of the UV-treated exhaust gas is greater than or equal to 99.99%.
In the invention, the product after the UV treatment of the tail gas contains nano particles, wherein the nano particles refer to particles with the particle size of less than 1 mu m.
Drawings
Fig. 1 is a schematic perspective view of an exhaust gas treatment device in an embodiment of an engine exhaust gas dedusting system according to the present invention.
Fig. 2 is a schematic structural diagram of an umbrella-shaped tail gas insulation mechanism of a tail gas processing device in an engine tail gas dust removal system according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of an engine exhaust gas dedusting system according to embodiment 2 of the present invention.
Fig. 4 is a schematic structural view of the electric field generating unit.
Fig. 5 is a view a-a of the electric field generating unit of fig. 4.
FIG. 6 is a view A-A of the electric field generating unit of FIG. 4, taken along the lines of length and angle.
FIG. 7 is a schematic diagram of an electric field device configuration for two electric field levels.
Fig. 8 is a schematic structural diagram of an electric field device in embodiment 19 of the present invention.
Fig. 9 is a schematic structural view of an electric field device in embodiment 21 of the present invention.
Fig. 10 is a schematic structural view of an electric field device in embodiment 22 of the present invention.
Fig. 11 is a schematic structural diagram of an exhaust gas temperature reducing device in embodiment 24 of the present invention.
FIG. 12 is a schematic flow chart of a test apparatus in example 25 of the present invention.
FIG. 13 is a graph showing the VOCs concentration and VOCs removal rate as a function of time at the device outlet of the electric field device in accordance with example 25 of the present invention.
FIG. 14 shows the CO at the outlet of the electric field apparatus in accordance with example 25 of the present invention2Concentration profile over treatment time.
FIG. 15 is a graph showing the variation of PM2.5 with processing time at the device outlet of the electric field device in accordance with example 25 of the present invention.
FIG. 16 is a schematic flow chart of a test apparatus in example 31 of the present invention.
FIG. 17 is a graph showing the time-dependent changes in the concentrations of VOCs at the inlet, outlet and outlet of the ultraviolet light unit and the adsorption unit when purifying low concentrations of VOCs in example 31 of the present invention.
FIG. 18 shows the CO at the inlet, outlet and outlet of the ultraviolet device and the adsorption device for purifying low concentrations of VOCs in example 31 of the present invention2Concentration versus time curve.
FIG. 19 is a graph showing the time-dependent changes in the concentrations of VOCs at the inlet, outlet and outlet of the ultraviolet light unit and the adsorption unit when purifying high concentrations of VOCs in example 31 of the present invention.
FIG. 20 shows the CO at the inlet, outlet and outlet of the ultraviolet device and the adsorption device for purifying high concentrations of VOCs in example 31 of the present invention2Concentration versus time curve.
Detailed Description
The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.
It should be understood that the structures, ratios, sizes, and the like shown in the drawings and described in the specification are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions under which the present invention can be implemented, so that the present invention has no technical significance, and any structural modification, ratio relationship change, or size adjustment should still fall within the scope of the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.
The engine tail gas dust removal system is communicated with an outlet of an engine. The exhaust gas discharged by the engine flows through the engine exhaust gas dedusting system.
In some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the device comprises an inlet, an outlet and a flow channel, and is characterized by further comprising an ultraviolet device and a tail gas electric field device, wherein the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet. When the system for treating VOCs in engine tail gas works, gas enters the flow channel from the inlet, enters the ultraviolet device in the flow channel, enters the electric field device after being treated by ultraviolet, is used for removing particles in the gas after being treated by ultraviolet, and is discharged from the outlet.
In an embodiment of the present invention, the UV treatment and the electric field dust removal are combined to purify the VOCs gas, and the following technical effects are obtained:
the research of the invention discovers that the engine tail containing VOCsThe product of the gas after UV irradiation is not only CO2And H2O, also large molecular weight nano-sized solid particles are present, for example, the present invention is confirmed by a large amount of experimental data: the PM2.5 content in the product after the tail gas is treated by the UV is increased compared with that before the UV irradiation, the nano-scale particles in the product treated by the UV are greatly increased, wherein the PN value of the solid particles with the particle size of 23nm is increased by more than 1 time, and secondary pollution can be caused if the product treated by the UV irradiation is directly discharged. Therefore, removal of particulate matter is a consideration in the art of UV treatment of gases containing VOCs. However, the prior art does not find relevant research on removing nano-particles in the product after the UV irradiation treatment, and does not disclose a technology for effectively removing nano-particles in the gas. According to the invention, the electric field is used for dedusting to effectively remove the nano particles in the product after UV irradiation treatment, the removal efficiency of the particles with the particle size of 23nm reaches more than 99.99%, and secondary pollution is avoided.
In some embodiments of the present invention, the ultraviolet device comprises at least one ultraviolet lamp.
In some embodiments of the present invention, the UV light provided by the UV lamp is single-peak UV light or dual-peak UV light.
In some embodiments of the present invention, the ultraviolet lamp provides a single peak of ultraviolet light having a main peak of 253.7nm or 185 nm.
In some embodiments of the present invention, the dominant peaks of the dual-peak ultraviolet light provided by the ultraviolet lamp are 253.7nm and 185nm, respectively.
In some embodiments of the present invention, the system for treating VOCs in engine exhaust further includes an adsorption device disposed in a flow channel of the system for treating VOCs in engine exhaust.
In some embodiments of the present invention, the adsorption device is located between the ultraviolet device and the electric field device.
In some embodiments of the present invention, the adsorption device includes a gas inlet and a gas outlet, the gas inlet of the adsorption device is communicated with the gas outlet of the ultraviolet device, and the gas outlet of the adsorption device is communicated with the electric field device inlet of the electric field device.
In the inventionIn some embodiments, the adsorbent device is provided with an adsorbent material, which includes but is not limited to activated carbon, molecular sieves, and any other adsorbent material capable of adsorbing at least one of VOCs, products and intermediates of VOCs generated during photolysis, ozone oxidation, UV light-activated oxidation, etc., such as photolysis product O of VOCs3The material of (1).
In certain embodiments of the present invention, the adsorbent material comprises at least one of a hydrophilic engineered activated carbon, a hydrophobic engineered molecular sieve.
In an embodiment of the present invention, the adsorption purification technique functions as follows:
firstly, the method comprises the following steps: in the ultraviolet treatment stage, the UV light can not completely treat VOCs in the engine tail gas into CO2And H2O, intermediate products are produced, all VOCs components cannot be degraded, H is in the adsorption device2O, UV products of light irradiation such as O3、OH-The intermediate product and the VOCs components which are not subjected to degradation are adsorbed and collected, and the UV intermediate product and the VOCs components which are not subjected to degradation are adsorbed in the pore passage of the adsorbing material and are subjected to O3、OH-Further decomposing into CO under the action of an equal-strength oxidant2And H2O, from desorption in the adsorption material pore, play the additional action to UV illumination processing VOCs, realize online desorption simultaneously, avoid the adsorbent inefficacy, ensure adsorbent repeatedly usable, improved VOCs treatment effeciency.
Secondly, the method comprises the following steps: economically, in practical application, the release amount of VOCs is not constant, when the concentration of VOCs is high, the VOCs cannot be completely degraded by UV light, the residual VOCs (VOCs which are not degraded by UV light in the ultraviolet purification stage) are adsorbed in the adsorbing material, stored and concentrated by aggregation, and the product O is irradiated by UV light3、OH-Further oxidized and decomposed again under the action of an equal-strength oxidant; when the concentration of VOCs is very low, strong oxidized ion hydroxyl free radical (OH) generated by the ultraviolet device enters the adsorption device to further catalyze the VOCs stored in the adsorption material into CO2And H2And O. This improves the efficiency of VOCs gas treatment, saves energy consumption, and also realizes VOCsThe gas processing apparatus is miniaturized.
Thirdly, the method comprises the following steps: the adsorption material can adsorb the ozone generated by photolysis, and the adsorbed ozone can oxidize VOCs accumulated in the adsorption material, so that O3Fully utilizes the ozone and avoids secondary pollution caused by the ozone.
In an embodiment of the present invention, the combination of the ultraviolet purification and the adsorption purification improves efficiency of UV purifying the VOCs gas, saves energy consumption, and miniaturizes a system for processing VOCs in the engine exhaust.
In some embodiments of the present invention, a method for treating VOCs in engine exhaust is provided, comprising the steps of:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
and (4) performing electric field dust removal treatment on the product after the UV treatment of the tail gas to remove particles.
In an embodiment of the invention, the method for treating VOCs in engine exhaust further includes performing electric field dedusting treatment on the gas before the UV treatment.
In an embodiment of the present invention, the method for treating VOCs in engine exhaust further includes performing adsorption treatment on a product obtained after UV treatment of the exhaust, and then performing electric field dust removal treatment.
In an embodiment of the present invention, the adsorbent for adsorption treatment is activated carbon and/or molecular sieve.
In one embodiment of the present invention, at least one ultraviolet lamp is used for the UV irradiation treatment.
In an embodiment of the invention, the UV light provided by the UV lamp is single-peak UV light or dual-peak UV light.
In an embodiment of the invention, the ultraviolet lamp provides a main peak of the single-peak ultraviolet light of 253.7nm or 185 nm.
In an embodiment of the invention, the dominant peaks of the dual-peak ultraviolet light provided by the ultraviolet lamp are 253.7nm and 185nm, respectively.
In an embodiment of the invention, the product after the UV treatment of the exhaust gas contains nano-particles, and the removing of the particles in the product after the UV treatment of the exhaust gas includes removing the nano-particles in the product after the UV treatment of the exhaust gas.
In an embodiment of the invention, the product after UV treatment of the exhaust gas contains particles smaller than 50nm, and the removing of the particles in the product after UV treatment of the exhaust gas includes removing the particles smaller than 50nm in the product after UV treatment of the exhaust gas.
In an embodiment of the invention, the product after UV treatment of the exhaust gas contains 15 to 35 nm of particles, and the removal of the particles in the product after UV treatment of the exhaust gas includes removal of 15 to 35 nm of particles in the product after UV treatment of the exhaust gas.
In an embodiment of the present invention, the product after UV treatment of the exhaust gas contains 23nm of particulate matter, and the removing of the particulate matter in the product after UV treatment of the exhaust gas includes removing 23nm of particulate matter in the product after UV treatment of the exhaust gas.
In an embodiment of the invention, the removal rate of the 23nm particulate matters in the product after the removal of the UV-treated tail gas is greater than or equal to 93%.
In an embodiment of the invention, the removal rate of the 23nm particulate matters in the product after the removal of the UV-treated tail gas is greater than or equal to 95%.
In an embodiment of the invention, the removal rate of the 23nm particulate matters in the product after the UV-treated tail gas is removed is greater than or equal to 99.99%.
In one embodiment of the present invention, the inlet of the electric field device is communicated with the outlet of the engine.
In an embodiment of the present invention, the exhaust gas electric field device may include an electric field cathode and an electric field anode, and an ionization dust removal electric field is formed between the electric field cathode and the electric field anode. Tail gas gets into ionization dust removal electric field, and the oxygen ion in the tail gas will be ionized to form a large amount of oxygen ions that have an electric charge, particulate matters such as dust combine in oxygen ion and the tail gas, make the particulate matter lotus electric, the electric field positive pole exerts adsorption affinity for the particulate matter that has a negative charge, makes the particulate matter adsorbed on the electric field positive pole, in order to clear away the particulate matter in the tail gas.
In an embodiment of the present invention, the electric field cathode includes a plurality of cathode filaments. The diameter of the cathode filament can be 0.1mm-20mm, and the size parameter is adjusted according to the application occasion and the dust accumulation requirement. In one embodiment of the present invention, the diameter of the cathode filament is not greater than 3 mm. In one embodiment of the invention, the cathode wire is made of metal wire or alloy wire which is easy to discharge, is temperature resistant, can support the self weight and is stable in electrochemistry. In an embodiment of the present invention, the cathode filament is made of titanium. The specific shape of the cathode filament is adjusted according to the shape of the electric field anode, for example, if the dust deposition surface of the electric field anode is a plane, the section of the cathode filament is circular; if the dust deposition surface of the electric field anode is a circular arc surface, the cathode filament needs to be designed into a polyhedral shape. The length of the cathode filament is adjusted according to the electric field anode.
In one embodiment of the present invention, the electric field cathode includes a plurality of cathode bars. In one embodiment of the present invention, the diameter of the cathode bar is not greater than 3 mm. In one embodiment of the present invention, the cathode rod is made of a metal rod or an alloy rod which is easily discharged. The shape of the cathode rod may be needle-like, polygonal, burr-like, threaded rod-like, columnar, or the like. The shape of the cathode bar can be adjusted according to the shape of the electric field anode, for example, if the dust deposition surface of the electric field anode is a plane, the section of the cathode bar needs to be designed to be circular; if the dust deposition surface of the electric field anode is a circular arc surface, the cathode bar needs to be designed into a polyhedral shape.
In an embodiment of the present invention, the electric field cathode is disposed through the electric field anode.
In one embodiment of the invention, the electric field anode comprises one or more hollow anode tubes arranged in parallel. When there are a plurality of hollow anode tubes, all the hollow anode tubes constitute a honeycomb-shaped electric field anode. In an embodiment of the present invention, the cross-section of the hollow anode tube may be circular or polygonal. If the cross section of the hollow anode tube is circular, an even electric field can be formed between the electric field anode and the electric field cathode, and dust is not easy to accumulate on the inner wall of the hollow anode tube. If the cross section of the hollow anode tube is triangular, 3 dust accumulation surfaces can be formed on the inner wall of the hollow anode tube, 3 far-angle dust containing angles are formed, and the dust containing rate of the hollow anode tube with the structure is highest. If the cross section of the hollow anode tube is quadrilateral, 4 dust accumulation surfaces and 4 dust containing corners can be obtained, but the splicing structure is unstable. If the cross section of the hollow anode tube is hexagonal, 6 dust accumulation surfaces and 6 dust containing angles can be formed, and the dust accumulation surfaces and the dust containing rate are balanced. If the cross section of the hollow anode tube is polygonal, more dust-collecting edges can be obtained, but the dust holding rate is lost. In one embodiment of the invention, the diameter of the inner tangent circle of the hollow anode tube ranges from 5mm to 400 mm.
In an embodiment of the invention, the electric field cathode is arranged on the cathode supporting plate, and the cathode supporting plate is connected with the electric field anode through the tail gas insulation mechanism. In an embodiment of the present invention, the electric field anode includes a first anode portion and a second anode portion, i.e., the first anode portion is close to the inlet of the dust removing device, and the second anode portion is close to the outlet of the dust removing device. The cathode supporting plate and the tail gas insulating mechanism are arranged between the first anode part and the second anode part, namely the tail gas insulating mechanism is arranged in the middle of an ionization electric field or in the middle of an electric field cathode, so that the electric field cathode can be well supported, the electric field cathode can be fixed relative to the electric field anode, and a set distance is kept between the electric field cathode and the electric field anode. In the prior art, the supporting point of the cathode is at the end point of the cathode, and the distance between the cathode and the anode is difficult to maintain. In an embodiment of the present invention, the tail gas insulation mechanism is disposed outside the dust removal flow channel to prevent or reduce dust in the tail gas from accumulating on the tail gas insulation mechanism, which may cause the tail gas insulation mechanism to break down or conduct electricity.
In an embodiment of the invention, the tail gas insulation mechanism adopts a high-voltage-resistant ceramic insulator to insulate the electric field cathode and the electric field anode. The electric field anode is also referred to as a housing.
In an embodiment of the invention, the first anode portion is located in front of the cathode support plate and the tail gas insulation mechanism in the gas flowing direction, and the first anode portion can remove water in the tail gas to prevent water from entering the tail gas insulation mechanism to cause short circuit and ignition of the tail gas insulation mechanism. In addition, the third positive part can remove a considerable part of dust in the tail gas, and when the tail gas passes through the tail gas insulation mechanism, the considerable part of dust is eliminated, so that the possibility that the tail gas insulation mechanism is short-circuited due to the dust is reduced. In an embodiment of the present invention, the tail gas insulation mechanism includes an insulation knob. The design of first anode portion mainly is in order to protect insulating knob insulator not polluted by particulate matter etc. in the gas, in case gas pollution insulating knob insulator will cause electric field positive pole and electric field negative pole to switch on to the laying dust function that makes electric field positive pole is inefficacy, so the design of first anode portion can effectively reduce insulating knob insulator and be polluted, improves the live time of product. In the process that the tail gas flows through the second-stage flow channel, the first anode part and the electric field cathode contact polluted gas firstly, and the tail gas insulating mechanism contacts the gas later, so that the purpose of removing dust firstly and then passing through the tail gas insulating mechanism is achieved, the pollution to the tail gas insulating mechanism is reduced, the cleaning and maintenance period is prolonged, and the corresponding electrode is supported in an insulating mode after being used. In an embodiment of the present invention, the length of the first anode portion is long enough to remove a portion of dust, reduce dust accumulated on the tail gas insulation mechanism and the cathode support plate, and reduce electrical breakdown caused by dust. In an embodiment of the invention, the length of the first anode portion accounts for 1/10-1/4, 1/4-1/3, 1/3-1/2, 1/2-2/3, 2/3-3/4, or 3/4-9/10 of the total length of the electric field anode.
In one embodiment of the invention the second anode portion is located after the cathode support plate and the tail gas insulating means in the flow direction of the tail gas. The second anode part comprises a dust deposition section and a reserved dust deposition section. The dust accumulation section adsorbs particles in the tail gas by utilizing static electricity, and the dust accumulation section is used for increasing the dust accumulation area and prolonging the service time of the tail gas electric field device. The reserved dust accumulation section can provide failure protection for the dust accumulation section. The dust accumulation section is reserved to further increase the dust accumulation area on the premise of meeting the design dust removal requirement. And reserving a dust accumulation section for supplementing the dust accumulation of the front section. In an embodiment of the invention, the reserved dust-laying section and the first anode part can use different power supplies.
In an embodiment of the present invention, since there is a very high potential difference between the cathode and the anode of the electric field, in order to prevent the cathode and the anode of the electric field from being conducted, the tail gas insulation mechanism is disposed outside the second-stage flow channel between the cathode and the anode of the electric field. Therefore, the tail gas insulation mechanism is suspended outside the anode of the electric field. In an embodiment of the present invention, the tail gas insulation mechanism may be made of a non-conductive temperature-resistant material, such as ceramic, glass, etc. In one embodiment of the invention, the insulation of the completely closed air-free material requires that the insulation isolation thickness is more than 0.3 mm/kv; air insulation requirements >1.4 mm/kv. The insulation distance may be set according to 1.4 times or more of the inter-polar distance between the electric field cathode and the electric field anode. In one embodiment of the invention, the tail gas insulation mechanism is made of ceramic, and the surface of the tail gas insulation mechanism is glazed; the connection can not be filled by using adhesive or organic materials, and the temperature resistance is higher than 350 ℃.
In an embodiment of the present invention, the exhaust gas insulation mechanism includes an insulation portion and a heat insulation portion. In order to enable the tail gas insulation mechanism to have an anti-pollution function, the material of the insulation part is made of a ceramic material or a glass material. In an embodiment of the invention, the insulating part can be an umbrella-shaped ceramic column or a glass column, and glaze is hung inside and outside the umbrella. The distance between the outer edge of the umbrella-shaped string ceramic column or the glass column and the anode of the electric field is more than or equal to 1.4 times of the distance of the electric field, namely more than or equal to 1.4 times of the distance between the electrodes. The sum of the distances between the umbrella protruding edges of the umbrella-shaped string ceramic columns or the glass columns is more than or equal to 1.4 times of the insulation distance of the umbrella-shaped string ceramic columns. The total depth of the umbrella edge of the umbrella-shaped string ceramic column or the glass column is more than or equal to 1.4 times of the insulation distance of the umbrella-shaped string ceramic column. The insulating part can also be a columnar ceramic column or a glass column, and glaze is hung inside and outside the column. In an embodiment of the invention, the insulating portion may also be in a tower shape.
In an embodiment of the present invention, a heating rod is disposed in the insulating portion, and when the ambient temperature of the insulating portion approaches the dew point, the heating rod is activated to perform heating. Because the inside and outside of the insulating part have temperature difference during use, condensation is easily generated inside and outside the insulating part. The outer surface of the insulation may be heated spontaneously or by gas to generate high temperature, which requires necessary insulation protection and scalding prevention. The heat insulation part comprises a protective enclosure baffle positioned outside the second insulation part and a denitration purification reaction cavity. In an embodiment of the invention, the tail part of the insulating part needs to be insulated from the condensation position, so that the condensation component is prevented from being heated by the environment and the heat dissipation high temperature.
In one embodiment of the invention, the outgoing line of the power supply of the tail gas electric field device is connected in an umbrella-shaped string ceramic column or glass column through-wall mode, the elastic contact head is used for connecting the cathode supporting plate in the wall, the sealed insulating protection wiring cap is used for plugging and pulling connection outside the wall, and the insulating distance between the outgoing line through-wall conductor and the wall is larger than the ceramic insulating distance between the umbrella-shaped string ceramic column or the glass column. In one embodiment of the invention, the high-voltage part is provided with no lead and is directly arranged on the end head, so that the safety is ensured, the high-voltage module is wholly insulated and protected by ip68, and heat exchange and heat dissipation are realized by using a medium.
In an embodiment of the invention, the electric field anode and the electric field cathode are electrically connected to two electrodes of the power supply respectively. The voltage loaded on the electric field anode and the electric field cathode needs to select a proper voltage grade, and the specific voltage grade depends on the volume, temperature resistance, dust holding rate and the like of the tail gas electric field device. For example, the voltage is from 1kv to 50 kv; the design firstly considers the temperature-resistant condition, the parameters of the inter-polar distance and the temperature: 1MM is less than 30 degrees, the dust accumulation area is more than 0.1 square/kilocubic meter/hour, the length of the electric field is more than 5 times of the inscribed circle of the single tube, and the air flow velocity of the electric field is controlled to be less than 9 meters/second. In an embodiment of the present invention, the electric field anode is formed of a second hollow anode tube and has a honeycomb shape. The second hollow anode tube port may be circular or polygonal in shape. In one embodiment of the invention, the value range of the internal tangent circle of the second hollow anode tube is 5-400mm, the corresponding voltage is 0.1-120kv, and the corresponding current of the second hollow anode tube is 0.1-30A; different inscribed circles correspond to different corona voltages, approximately 1KV/1 MM.
In an embodiment of the invention, the exhaust gas electric field device includes a second electric field stage, and the second electric field stage includes a plurality of second electric field generating units, and there may be one or more second electric field generating units. The second electric field generating unit is also called a second dust collecting unit, and the second dust collecting unit comprises the electric field anode and the electric field cathode, and the second dust collecting unit is provided with one or more than one. When the second electric field is multiple, the dust collecting efficiency of the tail gas electric field device can be effectively improved. In the same second electric field stage, the anodes of the electric fields have the same polarity, and the cathodes of the electric fields have the same polarity. And when the second electric field stage is multiple, all the second electric field stages are connected in series. In one embodiment of the invention, the tail gas electric field device further comprises a plurality of connecting shells, and the second electric field stages connected in series are connected through the connecting shells; the distance of the second electric field stage of two adjacent stages is more than 1.4 times of the pole pitch.
The inventor of the present invention has found that the disadvantage of the electric field dust removing device in the prior art is caused by electric field coupling. The invention can obviously reduce the size (namely the volume) of the electric field dust removal device by reducing the coupling times of the electric field. For example, the size of the ionization dust removal device provided by the invention is about one fifth of the size of the existing ionization dust removal device. The reason is that the gas flow rate is set to be about 1m/s in the existing ionized dust removing device in order to obtain acceptable particle removal rate, but the invention can still obtain higher particle removal rate under the condition of increasing the gas flow rate to 6 m/s. When a given flow of gas is treated, the size of the electric field dust collector can be reduced as the gas velocity is increased.
In addition, the invention can obviously improve the particle removal efficiency. For example, the prior art electric field dust removing device can remove about 70% of the particulate matter in the engine exhaust gas at a gas flow rate of about 1m/s, but the present invention can remove about 99% of the particulate matter even at a gas flow rate of 6 m/s. Therefore, the present invention can satisfy the latest emission standards.
The present invention achieves the above-noted unexpected results as the inventors have discovered the effect of electric field coupling and have found a way to reduce the number of electric field couplings. Therefore, the present invention can be used to manufacture an electric field dust removing apparatus suitable for vehicles.
The method for reducing the coupling frequency of the electric field provided by the invention comprises the following steps:
in one embodiment of the present invention, an asymmetric structure is adopted between the electric field cathode and the electric field anode. In the symmetrical electric field, the polar particles are subjected to an acting force with the same magnitude and opposite directions, and the polar particles reciprocate in the electric field; in an asymmetric electric field, the polar particles are subjected to two acting forces with different magnitudes, and the polar particles move towards the direction with the large acting force, so that the generation of coupling can be avoided.
In some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet; the tail gas electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field; the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is 1.667: 1-1680: 1.
in an embodiment of the present invention, a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode is 6.67: 1-56.67: 1.
in an embodiment of the present invention, the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is such that the coupling frequency of the ionization dust removal electric field is less than or equal to 3.
In an embodiment of the present invention, the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode, the inter-polar distance between the electric field anode and the electric field cathode, the length of the electric field anode, and the length of the electric field cathode enable the coupling frequency of the ionization dust removal electric field to be less than or equal to 3.
In an embodiment of the present invention, a method for treating VOCs in engine exhaust is provided, which includes the following steps:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
carrying out electric field dust removal treatment on the UV-treated product to remove particles in the UV-treated product;
the electric field dust removal treatment also comprises a method for reducing the coupling of a dust removal electric field, and the method for reducing the coupling of the dust removal electric field comprises the following steps: comprises selecting the ratio of the dust collecting area of the electric field anode to the discharging area of the electric field cathode to make the electric field coupling frequency less than or equal to 3.
In an embodiment of the present invention, the method further includes selecting a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode to be 1.667: 1-1680: 1. in an embodiment of the present invention, the method further includes selecting a ratio of a dust deposition area of the electric field anode to a discharge area of the electric field cathode to be 6.67: 1-56.67: 1. in one embodiment of the present invention, the diameter of the electric field cathode is selected to be 1-3 mm, and the inter-polar distance between the electric field anode and the electric field cathode is selected to be 2.5-139.9 mm; the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is 1.667: 1-1680: 1.
in some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet; the tail gas electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field; the length of the electric field anode is 10-180 mm.
In an embodiment of the present invention, the length of the electric field anode is 60-180 mm.
In an embodiment of the present invention, the length of the electric field anode enables the coupling frequency of the ionization dust removal electric field to be less than or equal to 3.
In some embodiments of the present invention, a method for treating VOCs in engine exhaust is provided, which includes the following steps:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
carrying out electric field dust removal treatment on the UV-treated product to remove particles in the UV-treated product;
the electric field dust removal treatment also comprises a method for reducing the coupling of a dust removal electric field, and the method for reducing the coupling of the dust removal electric field comprises the following steps: comprises selecting the length of the anode of the electric field to make the coupling frequency of the electric field less than or equal to 3.
In one embodiment of the present invention, the length of the electric field anode is selected to be 10-180 mm.
In one embodiment of the present invention, the length of the electric field anode is selected to be 60-180 mm.
In some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet; the tail gas electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field; the length of the electric field cathode is 30-180 mm.
In one embodiment of the present invention, the length of the electric field cathode is 54-176 mm.
In an embodiment of the present invention, the length of the electric field anode enables the coupling frequency of the ionization dust removal electric field to be less than or equal to 3.
In some embodiments of the present invention, a method for treating VOCs in engine exhaust is provided, which includes the following steps:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
carrying out electric field dust removal treatment on the UV-treated product to remove particles in the UV-treated product;
the electric field dust removal treatment also comprises a method for reducing the coupling of a dust removal electric field, and the method for reducing the coupling of the dust removal electric field comprises the following steps:
comprises selecting the length of the cathode of the electric field to make the coupling frequency of the electric field less than or equal to 3.
In one embodiment of the present invention, the length of the electric field cathode is selected to be 30-180 mm.
In one embodiment of the present invention, the method includes selecting the length of the electric field cathode to be 54-176 mm.
In some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet; the tail gas electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field; the distance between the electric field anode and the electric field cathode is less than 150 mm.
In an embodiment of the present invention, the inter-polar distance between the electric field anode and the electric field cathode is 2.5-139.9 mm.
In an embodiment of the present invention, the inter-polar distance between the electric field anode and the electric field cathode is 5-100 mm.
In an embodiment of the present invention, the inter-polar distance between the electric field anode and the electric field cathode enables the coupling frequency of the ionization dust removal electric field to be less than or equal to 3.
In some embodiments of the present invention, a method for treating VOCs in engine exhaust is provided, which includes the following steps:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
carrying out electric field dust removal treatment on the UV-treated product to remove particles in the UV-treated product;
the electric field dust removal treatment also comprises a method for reducing the coupling of a dust removal electric field, and the method for reducing the coupling of the dust removal electric field comprises the following steps:
selecting the inter-polar distance between the electric field anode and the electric field cathode to ensure that the electric field coupling frequency is less than or equal to 3.
In an embodiment of the present invention, the distance between the anode and the cathode is selected to be 2.5-139.9 mm.
In an embodiment of the present invention, the distance between the anode and the cathode is selected to be 5-100 mm.
An ionization dust removal electric field is formed between an electric field cathode and an electric field anode of the tail gas electric field device. In order to reduce the electric field coupling of the electric field for the ionization and dust removal, in an embodiment of the present invention, the method for reducing the electric field coupling includes the following steps: the ratio of the dust collecting area of the electric field anode to the discharging area of the electric field cathode is selected to make the electric field coupling frequency less than or equal to 3. In an embodiment of the present invention, a ratio of the dust collecting area of the electric field anode to the discharging area of the electric field cathode may be: 1.667: 1-1680: 1; 3.334: 1-113.34: 1; 6.67: 1-56.67: 1; 13.34: 1-28.33: 1. the embodiment selects the relatively large-area dust collecting area of the electric field anode and the relatively small-area discharge area of the electric field cathode, and specifically selects the area ratio, so that the discharge area of the electric field cathode can be reduced, the suction force is reduced, the dust collecting area of the electric field anode is enlarged, the suction force is enlarged, namely, asymmetric electrode suction force is generated between the electric field cathode and the electric field anode, dust after charging falls into the dust collecting surface of the electric field anode, although the polarity is changed, the dust cannot be sucked away by the electric field cathode, the electric field coupling is reduced, and the electric field coupling frequency is less than or equal to 3. That is, when the electric field interpolar distance is less than 150mm, the electric field coupling frequency is less than or equal to 3, the electric field energy consumption is low, the coupling consumption of the electric field to aerosol, water mist, oil mist and loose and smooth particles can be reduced, and the electric field electric energy is saved by 30-50%. The dust collection area refers to the area of the working surface of the electric field anode, for example, if the electric field anode is in a hollow regular hexagon tube shape, the dust collection area is the inner surface area of the hollow regular hexagon tube shape, and the dust collection area is also called as the dust deposition area. The discharge area refers to the area of the working surface of the cathode of the electric field, for example, if the cathode of the electric field is rod-shaped, the discharge area is the outer surface area of the rod.
In an embodiment of the invention, the length of the electric field anode can be 10-180mm, 10-20 mm, 20-30 mm, 60-180mm, 30-40 mm, 40-50 mm, 50-60 mm, 60-70 mm, 70-80 mm, 80-90 mm, 90-100 mm, 100-110 mm, 110-120 mm, 120-130 mm, 130-140 mm, 140-150 mm, 150-160 mm, 160-170 mm, 170-180 mm, 60mm, 180mm, 10mm or 30 mm. The length of the electric field anode refers to the minimum length from one end of the working surface of the electric field anode to the other end. The length of the electric field anode is selected to effectively reduce electric field coupling.
In an embodiment of the invention, the length of the electric field anode can be 10-90mm, 15-20 mm, 20-25 mm, 25-30 mm, 30-35 mm, 35-40 mm, 40-45 mm, 45-50 mm, 50-55 mm, 55-60 mm, 60-65 mm, 65-70 mm, 70-75 mm, 75-80 mm, 80-85 mm or 85-90 mm, and the design of the length can enable the electric field anode and the tail gas electric field device to have high temperature resistance and enable the tail gas electric field device to have high-efficiency dust collection capability under high temperature impact.
In an embodiment of the invention, the length of the electric field cathode may be 30-180mm, 54-176mm, 30-40 mm, 40-50 mm, 50-54 mm, 54-60 mm, 60-70 mm, 70-80 mm, 80-90 mm, 90-100 mm, 100-110 mm, 110-120 mm, 120-130 mm, 130-140 mm, 140-150 mm, 150-160 mm, 160-170 mm, 170-176 mm, 170-180 mm, 54mm, 180mm, or 30 mm. The length of the field cathode refers to the minimum length from one end of the working surface of the field cathode to the other. The length of the electric field cathode is selected to effectively reduce electric field coupling.
In an embodiment of the invention, the length of the electric field cathode may be 10-90mm, 15-20 mm, 20-25 mm, 25-30 mm, 30-35 mm, 35-40 mm, 40-45 mm, 45-50 mm, 50-55 mm, 55-60 mm, 60-65 mm, 65-70 mm, 70-75 mm, 75-80 mm, 80-85 mm or 85-90 mm, and the design of the length can make the electric field cathode and the tail gas electric field device have high temperature resistance, and make the tail gas electric field device have high-efficiency dust collecting capability under high temperature impact. Wherein, when the temperature of the electric field is 200 ℃, the corresponding dust collection efficiency is 99.9 percent; when the temperature of the electric field is 400 ℃, the corresponding dust collection efficiency is 90 percent; when the temperature of the electric field is 500 ℃, the corresponding dust collecting efficiency is 50%.
In an embodiment of the invention, the distance between the electric field anode and the electric field cathode may be 5-30 mm, 2.5-139.9mm, 9.9-139.9 mm, 2.5-9.9 mm, 9.9-20 mm, 20-30 mm, 30-40 mm, 40-50 mm, 50-60 mm, 60-70 mm, 70-80 mm, 80-90 mm, 90-100 mm, 100-110 mm, 110-120 mm, 120-130 mm, 130-139.9 mm, 9.9mm, 139.9mm, or 2.5 mm. The distance between the electric field anode and the electric field cathode is also referred to as the pole pitch. The inter-polar distance specifically refers to the minimum vertical distance between the working surfaces of the electric field anode and the electric field cathode. The selection of the polar distance can effectively reduce the electric field coupling and ensure that the tail gas electric field device has the high temperature resistance.
In an embodiment of the present invention, the diameter of the electric field cathode is 1-3 mm, and the inter-polar distance between the electric field anode and the electric field cathode is 2.5-139.9 mm; the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is 1.667: 1-1680: 1.
for the tail gas system, in an embodiment, the electric field dust removal processing method provided by the present invention further includes: a method for reducing tail gas dust removal electric field coupling comprises the following steps:
enabling the tail gas to pass through a tail gas ionization dust removal electric field generated by an electric field anode and an electric field cathode;
the electric field anode or/and the electric field cathode are selected.
In an embodiment of the present invention, the size of the electric field anode and/or the electric field cathode is selected such that the number of electric field couplings is less than or equal to 3.
Specifically, the ratio of the dust collection area of the field anode to the discharge area of the field cathode is selected. Preferably, the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is selected to be 1.667: 1-1680: 1.
more preferably, the ratio of the dust area of the electric field anode to the discharge area of the tail gas of the dust removal electric field cathode is selected to be 6.67: 1-56.67: 1.
in an embodiment of the present invention, the diameter of the electric field cathode is 1-3 mm, and the inter-polar distance between the electric field anode and the electric field cathode is 2.5-139.9 mm; the ratio of the dust deposition area of the electric field anode to the discharge area of the electric field cathode is 1.667: 1-1680: 1.
preferably, the inter-polar distance between the electric field anode and the electric field cathode is selected to be less than 150 mm.
Preferably, the distance between the electric field anode and the electric field cathode is selected to be 2.5-139.9 mm. More preferably, the distance between the electric field anode and the electric field cathode is selected to be 5.0-100 mm.
Preferably, the length of the electric field anode is selected to be 10-180 mm. More preferably, the length of the electric field anode is selected to be 60-180 mm.
Preferably, the length of the electric field cathode is selected to be 30-180 mm. More preferably, the length of the electric field cathode is selected to be 54-176 mm.
In some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet; the tail gas electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field; the electric field device also comprises an auxiliary electric field unit which is used for generating an auxiliary electric field which is not parallel to the ionization dust removal electric field.
In some embodiments of the present invention, a system for treating VOCs in engine exhaust is provided, comprising: an inlet, an outlet, and a flow channel between the inlet and the outlet; the ultraviolet device and the tail gas electric field device are sequentially arranged along the flow channel from the inlet to the outlet; the tail gas electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field; the electric field device further comprises an auxiliary electric field unit, the ionization dust removal electric field comprises a flow channel, and the auxiliary electric field unit is used for generating an auxiliary electric field which is not perpendicular to the flow channel.
In an embodiment of the present invention, the auxiliary electric field unit includes a first electrode, and the first electrode of the auxiliary electric field unit is disposed at or near an inlet of the ionization dust-removal electric field.
In an embodiment of the invention, the first electrode is a cathode.
In an embodiment of the invention, the first electrode of the auxiliary electric field unit is an extension of the electric field cathode.
In an embodiment of the present invention, the first electrode of the auxiliary electric field unit has an included angle α with the electric field anode, and 0 ° < α ≦ 125 °, or 45 ° ≦ α ≦ 125 °, or 60 ° ≦ α ≦ 100 °, or α ≦ 90 °.
In an embodiment of the invention, the auxiliary electric field unit includes a second electrode, and the second electrode of the auxiliary electric field unit is disposed at or near the outlet of the ionization dust-removal electric field.
In an embodiment of the invention, the second electrode is an anode.
In an embodiment of the invention, the second electrode of the auxiliary electric field unit is an extension of the electric field anode.
In one embodiment of the present invention, the second electrode of the auxiliary electric field unit has an angle α with the electric field cathode, and 0 ° < α ≦ 125 °, or 45 ° ≦ α ≦ 125 °, or 60 ° ≦ α ≦ 100 °, or α ≦ 90 °.
In an embodiment of the present invention, the electrodes of the auxiliary electric field and the electrodes of the ionization dust-removing electric field are independently disposed.
In some embodiments of the present invention, the electric field dust removing method further includes a method of providing an auxiliary electric field, including the steps of:
passing a gas through a flow channel;
generating an auxiliary electric field in the flow channel, the auxiliary electric field being non-perpendicular to the flow channel, the auxiliary electric field including an inlet and an outlet.
Wherein the auxiliary electric field ionizes the gas.
In an embodiment of the invention, the auxiliary electric field is generated by the auxiliary electric field unit, and the structure of the auxiliary electric field unit is the same as that of the auxiliary electric field unit in the electric field device.
The ionization dust removal electric field between the electric field anode and the electric field cathode in the tail gas electric field device is also called as a third electric field. In an embodiment of the invention, a fourth electric field not parallel to the third electric field is formed between the electric field anode and the electric field cathode. In another embodiment of the present invention, the flow channel of the fourth electric field and the flow channel of the ionized dust removing electric field are not perpendicular. The fourth electric field, also called auxiliary electric field, can be formed by one or two auxiliary electrodes. When the fourth electric field is formed by an auxiliary electrode, which may be placed at the entrance or exit of the ionizing electric field, the auxiliary electrode may be charged to a negative potential, or to a positive potential. When the auxiliary electrode is a cathode, the auxiliary electrode is arranged at or close to an inlet of the ionization dust removal electric field; the auxiliary electrode and the electric field anode form an included angle alpha, and the alpha is more than 0 degrees and less than or equal to 125 degrees, or more than or equal to 45 degrees and less than or equal to 125 degrees, or more than or equal to 60 degrees and less than or equal to 100 degrees, or more than or equal to 90 degrees. When the auxiliary electrode is an anode, the auxiliary electrode is arranged at or close to an outlet of the ionization dust removal electric field; the auxiliary electrode and the electric field cathode form an included angle alpha, and the alpha is more than 0 degrees and less than or equal to 125 degrees, or more than or equal to 45 degrees and less than or equal to 125 degrees, or more than or equal to 60 degrees and less than or equal to 100 degrees, or more than or equal to 90 degrees. When the fourth electric field is formed by two auxiliary electrodes, one of the auxiliary electrodes may be charged with a negative potential and the other auxiliary electrode may be charged with a positive potential; one auxiliary electrode may be placed at the inlet of the ionizing dedusting electric field and the other auxiliary electrode at the outlet of the ionizing dedusting electric field. In addition, the auxiliary electrode may be a part of the electric field cathode or the electric field anode, that is, the auxiliary electrode may be formed by an extension of the electric field cathode or the electric field anode, in which case the lengths of the electric field cathode and the electric field anode are different. The auxiliary electrode may be a single electrode, that is, the auxiliary electrode may not be a part of the electric field cathode or the electric field anode, and in this case, the voltage of the fourth electric field is different from the voltage of the third electric field, and may be individually controlled according to the operating condition.
In an embodiment of the invention, the engine exhaust gas dedusting system further includes a water removal device for removing liquid water before the inlet of the electric field device.
In an embodiment of the present invention, when the temperature of the exhaust gas or the temperature of the engine is lower than a certain temperature, the exhaust gas of the engine may contain liquid water, and the water removing device removes the liquid water in the exhaust gas.
In an embodiment of the present invention, the certain temperature is between 90 ℃ and 100 ℃.
In an embodiment of the present invention, the certain temperature is between 80 ℃ and 90 ℃.
In an embodiment of the present invention, the certain temperature is below 80 ℃.
In an embodiment of the present invention, the electric field dust removing method further includes: a tail gas dedusting method comprises the following steps: when the temperature of the tail gas is lower than 100 ℃, removing liquid water in the tail gas, and then ionizing and dedusting.
In one embodiment of the invention, when the temperature of the tail gas is more than or equal to 100 ℃, the tail gas is subjected to ionization dust removal.
In one embodiment of the invention, when the temperature of the tail gas is less than or equal to 90 ℃, the liquid water in the tail gas is removed, and then the tail gas is ionized for dust removal.
In one embodiment of the invention, when the temperature of the tail gas is less than or equal to 80 ℃, the liquid water in the tail gas is removed, and then the tail gas is ionized for dust removal.
In one embodiment of the invention, when the temperature of the tail gas is less than or equal to 70 ℃, the liquid water in the tail gas is removed, and then the tail gas is ionized for dust removal.
In one embodiment of the invention, the liquid water in the tail gas is removed by an electrocoagulation demisting method, and then ionized dust removal is carried out.
The following technical problems are not recognized by the person skilled in the art: when tail gas or engine temperature are low, have liquid water in the tail gas, adsorb on electric field negative pole and electric field positive pole, cause that tail gas ionization dust removal electric field discharges inhomogeneous, strike sparks, and the inventor of this application discovers this problem to propose engine tail gas dust pelletizing system and set up water trap for get rid of liquid water before the electric field device entry, liquid water has electric conductivity, can shorten ionization distance, lead to that tail gas ionization dust removal electric field discharges inhomogeneously, easily lead to the electrode to puncture. When the engine is in cold start, the water trap removes water drops, namely liquid water, in tail gas before the tail gas enters the inlet of the electric field device, so that the water drops, namely liquid water, in the tail gas are reduced, the discharge unevenness of an electric field for tail gas ionization dust removal and the breakdown of a cathode and an anode of the electric field are reduced, the ionization dust removal efficiency is improved, and unexpected technical effects are obtained. The water removal device is not particularly limited, and the invention can be applied to the removal of liquid water in tail gas in the prior art.
The present invention is further illustrated by the following specific examples.
Example 1
The system for treating VOCs in engine exhaust comprises an exhaust treatment device, wherein the exhaust treatment device is used for treating a product of exhaust gas to be discharged into the atmosphere after being treated by an ultraviolet device.
Fig. 1 is a schematic structural diagram of an exhaust gas treatment device in an embodiment. As shown in fig. 1, the exhaust gas treatment device 102 includes an exhaust gas electric field device 1021, an exhaust gas insulation mechanism 1022, and a water removal device.
The tail gas electric field device 1021 comprises an electric field anode 10211 and an electric field cathode 10212 arranged in the electric field anode 10211, an asymmetric electrostatic field is formed between the electric field anode 10211 and the electric field cathode 10212, wherein after the gas containing the particulate matters enters the tail gas electric field device 1021 through the exhaust port, the gas is ionized due to discharge of the electric field cathode 10212, so that the particulate matters obtain negative charges, move to the electric field anode 10211, and are deposited on the electric field cathode 10212.
Specifically, the electric field cathode 10212 is composed of a honeycomb-shaped and hollow anode tube bundle group, and the shape of the end opening of the anode tube bundle is hexagonal.
The electric field cathode 10212 includes a plurality of electrode rods, which are inserted through each anode tube bundle in the anode tube bundle group in a one-to-one correspondence manner, wherein the electrode rods are needle-shaped, polygonal, burred, threaded rod-shaped or columnar.
The ratio of the dust collection area of the electric field anode 10211 to the discharge area of the electric field cathode 10212 is 1680: 1, the distance between the electric field anode 10211 and the electric field cathode 10212 is 9.9mm, the length of the electric field anode 10211 is 60mm, and the length of the electric field cathode 10212 is 54 mm.
In this embodiment, the gas inlet end of the electric field cathode 10212 is lower than the gas inlet end of the electric field anode 10211, the gas outlet end of the electric field cathode 10212 is flush with the gas outlet end of the electric field anode 10211, an included angle α is formed between the gas inlet end of the electric field cathode 10212 and the gas inlet end of the electric field anode 10211, and α is 90 °, so that an accelerating electric field is formed inside the tail gas electric field device 1021, and more substances to be treated can be collected.
The exhaust gas insulation mechanism 1022 suspended outside the air duct includes an insulation part and a heat insulation part. The insulating part is made of ceramic materials or glass materials. The insulating part is an umbrella-shaped string ceramic column, and glaze is hung inside and outside the umbrella. Fig. 2 is a schematic structural diagram of an umbrella-shaped exhaust gas insulation mechanism in an embodiment.
As shown in fig. 1, in an embodiment of the present invention, the electric field cathode is mounted on the cathode support plate 10213, and the cathode support plate 10213 is connected to the electric field anode 10211 through the tail gas insulation mechanism 1022. In one embodiment of the present invention, the electric field anode 10211 comprises a first anode portion 102112 and a second anode portion 102111, i.e. the first anode portion 102112 is close to the inlet of the dust removing device, and the second anode portion 102111 is close to the outlet of the dust removing device. The cathode support plate 10213 and the tail gas insulation mechanism 1022 are disposed between the first anode portion 102112 and the second anode portion 102111, that is, the tail gas insulation mechanism 1022 is disposed between the ionization electric field and the electric field cathode 10212, so as to support the electric field cathode 10212 well and fix the electric field cathode 10212 relative to the electric field anode 10211, so as to maintain a predetermined distance between the electric field cathode 10212 and the electric field anode 10211.
The water removal device is used for removing liquid water before an inlet of the electric field device, when the temperature of tail gas is lower than 100 ℃, the water removal device removes the liquid water in the tail gas, and the water removal device is an electrocoagulation demisting device.
Example 2
As shown in fig. 3, the engine exhaust gas dedusting system includes a water removal device 207 and an exhaust gas electric field device. The tail gas electric field device comprises an electric field anode 10211 and an electric field cathode 10212, wherein the electric field anode 10211 and the electric field cathode 10212 are used for generating a tail gas ionization dust removal electric field. The water removal device 207 is used for removing liquid water before an inlet of the electric field device, when the temperature of tail gas is lower than 100 ℃, the water removal device removes the liquid water in the tail gas, the water removal device 207 is an electrocoagulation device, and the arrow direction in the figure is the tail gas flowing direction.
In this embodiment, a product obtained after the ultraviolet device treats VOCs in engine exhaust is treated, and the treatment method includes: a tail gas dedusting method comprises the following steps: when the temperature of the tail gas is lower than 100 ℃, removing liquid water in the tail gas, and then ionizing and dedusting, wherein the liquid water in the tail gas is removed by adopting an electrocoagulation demisting method, the tail gas is the tail gas generated when a gasoline engine is cold started, water drops, namely the liquid water, in the tail gas are reduced, uneven discharge of an electric field for ionizing and dedusting of the tail gas and breakdown of a cathode and an anode of the electric field are reduced, the ionizing and dedusting efficiency is improved, the ionizing and dedusting efficiency is more than 99.9%, and the ionizing and dedusting efficiency of the dedusting method for not removing the liquid water in the tail gas is lower than 70%. Therefore, when the temperature of the tail gas is lower than 100 ℃, liquid water in the tail gas is removed, then ionization dust removal is carried out, water drops, namely the liquid water, in the tail gas are reduced, uneven discharge of an electric field of the tail gas ionization dust removal and breakdown of a cathode and an anode of the electric field are reduced, and the ionization dust removal efficiency is improved.
Example 3
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for forming an exhaust gas ionization dust removal electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
As shown in fig. 4, 5 and 6, in the present embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, and the electric field cathode 4052 is inserted into the electric field anode 4051.
In this embodiment, a product obtained after the ultraviolet device treats VOCs in engine exhaust is treated, and the treatment method includes: a method of reducing electric field coupling comprising the steps of: the ratio of the dust collection area of the field anode 4051 to the discharge area of the field cathode 4052 was selected to be 6.67: 1, the inter-polar distance L3 between the electric field anode 4051 and the electric field cathode 4052 is 9.9mm, the length L1 of the electric field anode 4051 is 60mm, the length L2 of the electric field cathode 4052 is 54mm, the electric field anode 4051 comprises a tail gas flow channel comprising an inlet end and an outlet end, the electric field cathode 4052 is disposed in the exhaust gas flow channel, the electric field cathode 4052 extends along the direction of the electric field anode exhaust gas flow channel, the inlet end of the electric field anode 4051 is flush with the proximal inlet end of the electric field cathode 4052, an angle α is formed between the outlet end of the electric field anode 4051 and the proximal outlet end of the electric field cathode 4052, and α is 118 degrees, and then under the effect of electric field positive pole 4051 and electric field negative pole 4052, can collect more pending material, realize that electric field coupling number of times is less than or equal to 3, can reduce the electric field and to aerosol, water smoke, oil mist, loose smooth particulate matter's coupling consumption, save electric field electric energy 30 ~ 50%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the tail gas electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field level, the anode of each tail gas ionization dust removal electric field is of the same polarity, and the cathode of each tail gas ionization dust removal electric field is of the same polarity.
The electric field stages in the plurality of electric field stages are connected in series, the electric field stages in series are connected through the connecting shell, and the distance between the electric field stages of two adjacent stages is larger than 1.4 times of the inter-pole distance. As shown in fig. 7, the electric field levels are two stages, a first stage electric field 4053 and a second stage electric field 4054, and the first stage electric field 4053 and the second stage electric field 4054 are connected in series by a connecting housing 4055.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is the product of the ultraviolet device processing VOCs in the engine exhaust.
Example 4
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for forming an exhaust gas ionization dust removal electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, and the electric field cathode 4052 is inserted into the electric field anode 4051.
In this embodiment, a product obtained after the ultraviolet device treats VOCs in engine exhaust is treated, and the treatment method includes: a method of reducing electric field coupling comprising the steps of: the ratio of the dust collection area of the electric field anode 4051 to the discharge area of the electric field cathode 4052 was selected to be 1680: 1, the inter-polar distance between the electric field anode 4051 and the electric field cathode 4052 is 139.9mm, the length of the electric field anode 4051 is 180mm, the length of the electric field cathode 4052 is 180mm, the electric field anode 4051 comprises a tail gas fluid channel, the tail gas fluid channel comprises an inlet end and an outlet end, the electric field cathode 4052 is arranged in the tail gas fluid channel, the electric field cathode 4052 extends along the direction of the electric field anode tail gas fluid channel, the inlet end of the electric field anode 4051 is flush with the near inlet end of the electric field cathode 4052, the outlet end of the electric field anode 4051 is flush with the near outlet end of the electric field cathode 4052, and further under the action of the electric field anode 4051 and the electric field cathode 4052, more substances to be processed can be collected, the electric field coupling frequency is less than or equal to 3, the coupling consumption of the electric field to aerosol, water mist, oil mist and smooth particles can be reduced, and the electric field electric energy can be saved by 20-40%.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is the product of the ultraviolet device processing VOCs in the engine exhaust.
Example 5
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for forming an exhaust gas ionization dust removal electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, and the electric field cathode 4052 is inserted into the electric field anode 4051.
In this embodiment, a product obtained after the ultraviolet device treats VOCs in engine exhaust is treated, and the treatment method includes: a method of reducing electric field coupling comprising the steps of: the ratio of the dust collection area of the field anode 4051 to the discharge area of the field cathode 4052 was selected to be 1.667: 1, the inter-polar distance between the electric field anode 4051 and the electric field cathode 4052 is 2.4mm, the length of the electric field anode 4051 is 30mm, the length of the electric field cathode 4052 is 30mm, the electric field anode 4051 comprises a tail gas fluid channel, the tail gas fluid channel comprises an inlet end and an outlet end, the electric field cathode 4052 is arranged in the tail gas fluid channel, the electric field cathode 4052 extends along the direction of the electric field anode tail gas fluid channel, the inlet end of the electric field anode 4051 is flush with the near inlet end of the electric field cathode 4052, the outlet end of the electric field anode 4051 is flush with the near outlet end of the electric field cathode 4052, and further under the action of the electric field anode 4051 and the electric field cathode 4052, more substances to be processed can be collected, the electric field coupling frequency is less than or equal to 3, the coupling consumption of the electric field to aerosol, water mist, oil mist and smooth particles can be reduced, and the electric field electric energy can be saved by 10-30%.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is the product of the ultraviolet device processing VOCs in the engine exhaust.
Example 6
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for forming an exhaust gas ionization dust removal electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
As shown in fig. 4, 5 and 6, in the present embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, the electric field cathode 4052 is inserted into the electric field anode 4051, and the ratio of the dust collection area of the electric field anode 4051 to the discharge area of the electric field cathode 4052 is 6.67: 1, the distance L3 between the electric field anode 4051 and the electric field cathode 4052 is 9.9mm, the length L1 of the electric field anode 4051 is 60mm, the length L2 of the electric field cathode 4052 is 54mm, the electric field anode 4051 comprises a tail gas flow channel comprising an inlet end and an outlet end, the electric field cathode 4052 is disposed in the exhaust gas flow channel, the electric field cathode 4052 extends along the direction of the electric field anode exhaust gas flow channel, the inlet end of the electric field anode 4051 is flush with the proximal inlet end of the electric field cathode 4052, an angle α is formed between the outlet end of the electric field anode 4051 and the proximal outlet end of the electric field cathode 4052, and α is 118 degrees, and then under the effect of electric field positive pole 4051 and electric field negative pole 4052, can collect more pending material, guarantee that this electric field generating element's collection dust efficiency is higher, and typical tail gas granule pm0.23 collection dust efficiency is 99.99%, and typical 23nm granule removal efficiency is 99.99%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the tail gas electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field level, the anodes of the electric fields have the same polarity, and the cathodes of the electric fields have the same polarity.
The electric field stages in the plurality of electric field stages are connected in series, the electric field stages in series are connected through the connecting shell, and the distance between the electric field stages of two adjacent stages is larger than 1.4 times of the inter-pole distance. As shown in fig. 7, the electric field levels are two stages, a first stage electric field 4053 and a second stage electric field 4054, and the first stage electric field 4053 and the second stage electric field 4054 are connected in series by a connecting housing 4055.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is the product of the ultraviolet device processing VOCs in the engine exhaust.
Example 7
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, the electric field cathode 4052 is inserted into the electric field anode 4051, and the ratio of the dust collecting area of the electric field anode 4051 to the discharging area of the electric field cathode 4052 is 1680: 1, the inter-polar distance between electric field anode 4051 and electric field cathode 4052 is 139.9mm, electric field anode 4051 is 180mm in length, electric field cathode 4052 is 180mm in length, electric field anode 4051 includes the tail gas fluid passageway, the tail gas fluid passageway includes inlet end and exit end, electric field cathode 4052 is arranged in the tail gas fluid passageway, electric field cathode 4052 extends along electric field anode tail gas fluid passageway's direction, and the inlet end of electric field anode 4051 flushes with the nearly inlet end of electric field cathode 4052, and the exit end of electric field anode 4051 flushes with the nearly outlet end of electric field cathode 4052, and then under the effect of electric field anode 4051 and electric field cathode 4052, can collect more pending material, guarantees that the collection efficiency of this electric field device is higher, and typical tail gas granule pm0.23 collection efficiency is 99.99%, and typical 23nm granule gets rid of efficiency is 99.99%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the tail gas electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field level, the anodes of the electric fields have the same polarity, and the cathodes of the electric fields have the same polarity.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 8
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the field anode 4051 has a hollow regular hexagonal tube shape, the field cathode 4052 has a rod shape, the field cathode 4052 is inserted into the field anode 4051, and the ratio of the dust collection area of the field anode 4051 to the discharge area of the field cathode 4052 is 1.667: 1, the distance between the poles of the electric field anode 4051 and the electric field cathode 4052 is 2.4 mm. Electric field anode 4051 is 30mm in length, and electric field cathode 4052 is 30mm in length, electric field anode 4051 includes the tail gas fluid channel, the tail gas fluid channel includes entrance end and exit end, electric field cathode 4052 is arranged in the tail gas fluid channel, electric field cathode 4052 extends along electric field anode tail gas fluid channel's direction, and electric field anode 4051's entrance end flushes with electric field cathode 4052's nearly entrance end, and electric field anode 4051's exit end flushes with electric field cathode 4052's nearly exit end, and then under electric field anode 4051 and electric field cathode 4052's effect, can collect more pending material, guarantee that this electric field device's collection dust efficiency is higher, and typical tail gas granule pm0.23 collection efficiency is 99.99%, and typical 23nm granule removal efficiency is 99.99%.
In this embodiment, the electric field anode 4051 and the electric field cathode 4052 constitute a plurality of dust collecting units, so as to effectively improve the dust collecting efficiency of the exhaust gas electric field apparatus by using the plurality of dust collecting units.
In this embodiment, the substance to be treated may be granular dust, and the gas in this embodiment is a product obtained by treating VOCs in engine exhaust gas with an ultraviolet device.
Example 9
The system for treating VOCs in engine exhaust in this embodiment includes the exhaust gas electric field apparatus in embodiment 6, embodiment 7, or embodiment 8. The tail gas discharged by the engine firstly flows through the ultraviolet device, and the product of VOCs treated by the ultraviolet device flows through the tail gas electric field device, so that pollutants such as dust in the gas can be effectively removed by using the tail gas electric field device; and then, the treated gas is discharged to the atmosphere so as to reduce the influence of the tail gas of the engine on the atmosphere.
Example 10
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for forming an exhaust gas ionization dust removal electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 is in the shape of a hollow regular hexagonal tube, the electric field cathode 4052 is in the shape of a rod, the electric field cathode 4052 is inserted into the electric field anode 4051, the length of the electric field anode 4051 is 5cm, the length of the electric field cathode 4052 is 5cm, the electric field anode 4051 comprises a tail gas flow channel comprising an inlet end and an outlet end, the electric field cathode 4052 is disposed in the exhaust flow channel, the electric field cathode 4052 extends in the direction of the electric field anode exhaust flow channel, the inlet end of the electric field anode 4051 is flush with the proximal inlet end of the electric field cathode 4052, the outlet end of the electric field anode 4051 is flush with the proximal outlet end of the electric field cathode 4052, the electric field anode 4051 and the electric field cathode 4052 have a pole pitch of 9.9mm, and then the electric field anode 4051 and the electric field cathode 4052 can resist high temperature impact, and more substances to be treated can be collected, so that the dust collection efficiency of the electric field generation unit is higher. The dust collection efficiency is 99.9% corresponding to the electric field temperature of 200 ℃; the dust collection efficiency is 90% corresponding to the electric field temperature of 400 ℃; the electric field temperature of 500 ℃ corresponds to a dust collecting efficiency of 50%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field level, the anodes of the electric fields have the same polarity, and the cathodes of the electric fields have the same polarity.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 11
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 is in the shape of a hollow regular hexagonal tube, the electric field cathode 4052 is in the shape of a rod, the electric field cathode 4052 is inserted into the electric field anode 4051, the length of the electric field anode 4051 is 9cm, the length of the electric field cathode 4052 is 9cm, the electric field anode 4051 comprises a tail gas flow channel comprising an inlet end and an outlet end, the electric field cathode 4052 is disposed in the exhaust flow channel, the electric field cathode 4052 extends in the direction of the electric field anode exhaust flow channel, the inlet end of the electric field anode 4051 is flush with the proximal inlet end of the electric field cathode 4052, the outlet end of the electric field anode 4051 is flush with the proximal outlet end of the electric field cathode 4052, the electric field anode 4051 and the electric field cathode 4052 have a pole pitch of 139.9mm, and then the electric field anode 4051 and the electric field cathode 4052 can resist high temperature impact, and more substances to be treated can be collected, so that the dust collection efficiency of the electric field generation unit is higher. The dust collection efficiency is 99.9% corresponding to the electric field temperature of 200 ℃; the dust collection efficiency is 90% corresponding to the electric field temperature of 400 ℃; the electric field temperature of 500 ℃ corresponds to a dust collecting efficiency of 50%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field level, the anodes of the storage electric fields are of the same polarity, and the cathodes of the storage electric fields are of the same polarity.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 12
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 is in the shape of a hollow regular hexagonal tube, the electric field cathode 4052 is in the shape of a rod, the electric field cathode 4052 is inserted into the electric field anode 4051, the length of the electric field anode 4051 is 1cm, the length of the electric field cathode 4052 is 1cm, the electric field anode 4051 comprises a tail gas flow channel comprising an inlet end and an outlet end, the electric field cathode 4052 is disposed in the exhaust flow channel, the electric field cathode 4052 extends in the direction of the electric field anode exhaust flow channel, the inlet end of the electric field anode 4051 is flush with the proximal inlet end of the electric field cathode 4052, the outlet end of the electric field anode 4051 is flush with the proximal outlet end of the electric field cathode 4052, the electric field anode 4051 and the electric field cathode 4052 have a pole pitch of 2.4mm, and then the electric field anode 4051 and the electric field cathode 4052 can resist high temperature impact, and more substances to be treated can be collected, so that the dust collection efficiency of the electric field generation unit is higher. The dust collection efficiency is 99.9% corresponding to the electric field temperature of 200 ℃; the dust collection efficiency is 90% corresponding to the electric field temperature of 400 ℃; the electric field temperature of 500 ℃ corresponds to a dust collecting efficiency of 50%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field level, the anodes of the electric fields have the same polarity, and the cathodes of the electric fields have the same polarity.
The electric field stages in the plurality of electric field stages are connected in series, the electric field stages in series are connected through the connecting shell, and the distance between the electric field stages of two adjacent stages is larger than 1.4 times of the inter-pole distance. The electric field level is two levels, namely a first level electric field and a second level electric field, and the first level electric field and the second level electric field are connected in series through a connecting shell.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 13
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
As shown in fig. 4 and 5, in the present embodiment, the electric field anode 4051 is in the shape of a hollow regular hexagon tube, the electric field cathode 4052 is in the shape of a rod, the electric field cathode 4052 is inserted into the electric field anode 4051, the electric field anode 4051 has a length of 3cm, the electric field cathode 4052 has a length of 2cm, the electric field anode 4051 includes an exhaust gas flow channel, the exhaust gas flow channel includes an inlet end and an outlet end, the electric field cathode 4052 is disposed in the exhaust gas flow channel, the electric field cathode 4052 extends along the direction of the electric field anode exhaust gas flow channel, the inlet end of the electric field anode 4051 is flush with the proximal inlet end of the electric field cathode 4052, the outlet end of the electric field anode 4051 and the proximal outlet end of the electric field cathode 4052 have an included angle α, and α is 90 °, the distance between the electric field anode 4051 and the electric field cathode 4052 is 20mm, and the electric field anode 4051 and the electric field cathode 4052 are further resistant to high temperature impact, and more substances to be treated can be collected, so that the dust collection efficiency of the electric field generation unit is higher. The dust collection efficiency is 99.9% corresponding to the electric field temperature of 200 ℃; the dust collection efficiency is 90% corresponding to the electric field temperature of 400 ℃; the electric field temperature of 500 ℃ corresponds to a dust collecting efficiency of 50%.
The tail gas electric field device in the embodiment comprises a plurality of electric field stages formed by the electric field generating units, and the electric field stages are multiple, so that the dust collecting efficiency of the electric field device is effectively improved by utilizing a plurality of dust collecting units. In the same electric field stage, the dust collectors have the same polarity, and the discharge electrodes have the same polarity.
The electric field stages in the plurality of electric field stages are connected in series, the electric field stages in series are connected through the connecting shell, and the distance between the electric field stages of two adjacent stages is larger than 1.4 times of the inter-pole distance. As shown in fig. 7, the electric field level is two levels, i.e., a first level electric field and a second level electric field, and the first level electric field and the second level electric field are connected in series by the connecting housing.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 14
The system for treating VOCs in engine exhaust in this embodiment includes the exhaust gas electric field apparatus in embodiment 10, embodiment 11, embodiment 12, or embodiment 13. The tail gas discharged by the engine firstly flows through the ultraviolet device, and the product of VOCs treated by the ultraviolet device flows through the tail gas electric field device, so that pollutants such as dust in the tail gas are effectively removed by using the tail gas electric field device; and then, the treated gas is discharged to the atmosphere so as to reduce the influence of the tail gas of the engine on the atmosphere.
Example 15
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, the electric field cathode 4052 is inserted into the electric field anode 4051, the ratio of the dust collecting area of the electric field anode 4051 to the discharge area of the electric field cathode 4052 is 27.566:1, and the distance between the poles of the electric field anode 4051 and the electric field cathode 4052 is 2.3 mm. Electric field anode 4051 length is 5mm, and electric field cathode 4052 length is 4mm, electric field anode 4051 includes tail gas flow channel, tail gas flow channel includes entrance point and exit end, electric field cathode 4052 arranges in the tail gas flow channel, electric field cathode 4052 extends along electric field anode tail gas flow channel's direction, and electric field anode 4051's entrance point flushes with electric field cathode 4052's nearly entrance point, and electric field anode 4051's exit end flushes with electric field cathode 4052's nearly exit end, and then under electric field anode 4051 and electric field cathode 4052's effect, can collect more pending material, guarantees that this electric field device's collection dust collection efficiency is higher.
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 16
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, the electric field cathode 4052 is inserted into the electric field anode 4051, the ratio of the dust collecting area of the electric field anode 4051 to the discharging area of the electric field cathode 4052 is 1.108:1, and the distance between the poles of the electric field anode 4051 and the electric field cathode 4052 is 2.3 mm. Electric field anode 4051 length is 60mm, and electric field cathode 4052 length is 200mm, electric field anode 4051 includes tail gas flow channel, tail gas flow channel includes entrance end and exit end, electric field cathode 4052 arranges in the tail gas flow channel, electric field cathode 4052 extends along electric field anode tail gas flow channel's direction, and electric field anode 4051's entrance end flushes with electric field cathode 4052's nearly entrance end, and electric field anode 4051's exit end flushes with electric field cathode 4052's nearly exit end, and then under electric field anode 4051 and electric field cathode 4052's effect, can collect more pending material, guarantees that this electric field device's collection dust collection efficiency is higher
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 17
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, the electric field cathode 4052 is inserted into the electric field anode 4051, and the ratio of the dust collection area of the electric field anode 4051 to the discharge area of the electric field cathode 4052 is 3065: 1, the distance between the electric field anode 4051 and the electric field cathode 4052 is 249 mm. Electric field anode 4051 length is 2000mm, and electric field cathode 4052 length is 180mm, electric field anode 4051 includes tail gas flow channel, tail gas flow channel includes entrance end and exit end, electric field cathode 4052 arranges in the tail gas flow channel, electric field cathode 4052 extends along electric field anode tail gas flow channel's direction, and electric field anode 4051's entrance end flushes with electric field cathode 4052's nearly entrance end, and electric field anode 4051's exit end flushes with electric field cathode 4052's nearly exit end, and then under electric field anode 4051 and electric field cathode 4052's effect, can collect more pending material, guarantees that this electric field device's collection dust collection efficiency is higher
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 18
The electric field generating unit in this embodiment is applied to the exhaust gas electric field device, as shown in fig. 4, and includes an electric field anode 4051 and an electric field cathode 4052 for generating an electric field, where the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to two electrodes of a power supply, the power supply is a dc power supply, and the electric field anode 4051 and the electric field cathode 4052 are respectively electrically connected to an anode and a cathode of the dc power supply. In this embodiment the electric field anode 4051 has a positive potential and the electric field cathode 4052 has a negative potential.
The dc power supply in this embodiment may be a dc high voltage power supply. An electric field for ionization and dust removal of the exhaust gas is formed between the anode 4051 and the cathode 4052.
In this embodiment, the electric field anode 4051 has a hollow regular hexagonal tube shape, the electric field cathode 4052 has a rod shape, the electric field cathode 4052 is inserted into the electric field anode 4051, the ratio of the dust collection area of the electric field anode 4051 to the discharge area of the electric field cathode 4052 is 1.338:1, and the distance between the poles of the electric field anode 4051 and the electric field cathode 4052 is 5 mm. Electric field anode 4051 length is 2mm, and electric field cathode 4052 length is 10mm, electric field anode 4051 includes tail gas flow channel, tail gas flow channel includes entrance end and exit end, electric field cathode 4052 arranges in the tail gas flow channel, electric field cathode 4052 extends along electric field anode tail gas flow channel's direction, and electric field anode 4051's entrance end flushes with electric field cathode 4052's nearly entrance end, and electric field anode 4051's exit end flushes with electric field cathode 4052's nearly exit end, and then under electric field anode 4051 and electric field cathode 4052's effect, can collect more pending material, guarantees that this electric field device's collection dust collection efficiency is higher
In this embodiment, the material to be treated may be dust in the form of particles.
In this embodiment, the gas is a product of treating VOCs in engine exhaust gas by an ultraviolet device.
Example 19
The electric field device is applied to VOCs gas treatment system in engine exhaust in this embodiment, including dust removal electric field negative pole 5081 and dust removal electric field positive pole 5082 respectively with DC power supply's negative pole and positive pole electric connection, auxiliary electrode 5083 and DC power supply's positive pole electric connection. In this embodiment, the dedusting electric field cathode 5081 has a negative potential, and the dedusting electric field anode 5082 and the auxiliary electrode 5083 each have a positive potential.
Meanwhile, as shown in fig. 8, the auxiliary electrode 5083 is fixedly connected to the dedusting electric field anode 5082 in this embodiment. After the dedusting electric field anode 5082 is electrically connected to the anode of the dc power supply, the auxiliary electrode 5083 is also electrically connected to the anode of the dc power supply, and the auxiliary electrode 5083 and the dedusting electric field anode 5082 have the same positive potential.
As shown in fig. 8, the auxiliary electrode 5083 may extend in the front-rear direction in this embodiment, i.e., the length direction of the auxiliary electrode 5083 may be the same as the length direction of the dust removing field anode 5082.
As shown in fig. 8, in this embodiment, the dust removing electric field anode 5082 is tubular, the dust removing electric field cathode 5081 is rod-shaped, and the dust removing electric field cathode 5081 is inserted into the dust removing electric field anode 5082. In this embodiment, the auxiliary electrode 5083 is also tubular, and the auxiliary electrode 5083 and the dedusting electric field anode 5082 form an anode tube 5084. The front end of the anode tube 5084 is flush with the dedusting electric field cathode 5081, the rear end of the anode tube 5084 is extended rearward beyond the rear end of the dedusting electric field cathode 5081, and the portion of the anode tube 5084 extended rearward beyond the dedusting electric field cathode 5081 is the auxiliary electrode 5083. That is, in this embodiment, the dust removal electric field anode 5082 and the dust removal electric field cathode 5081 have the same length, and the dust removal electric field anode 5082 and the dust removal electric field cathode 5081 are opposite to each other in position in the front-rear direction; the auxiliary electrode 5083 is located behind the dedusting electric field anode 5082 and the dedusting electric field cathode 5081. Thus, an auxiliary electric field is formed between the auxiliary electrode 5083 and the dedusting electric field cathode 5081, and the auxiliary electric field applies a backward force to the negatively charged oxygen ion stream between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081, so that the negatively charged oxygen ion stream between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081 has a backward moving speed. When the gas containing the substances to be treated flows into the anode tube 5084 from front to back, the oxygen ions with negative charges are combined with the substances to be treated in the process of moving towards the anode 5082 of the dust removal electric field and moving backwards, and because the oxygen ions have backward moving speed, the oxygen ions are combined with the substances to be treated, and strong collision cannot be generated between the oxygen ions and the substances to be treated, so that the larger energy consumption caused by the strong collision is avoided, the oxygen ions are easily combined with the substances to be treated, the charging efficiency of the substances to be treated in the gas is higher, further, under the action of the anode 5082 of the dust removal electric field and the anode tube 5084, more substances to be treated can be collected, and the higher dust removal efficiency of the electric field device is ensured.
In addition, as shown in fig. 8, in the present embodiment, an angle α is formed between the rear end of the anode 5084 and the rear end of the dust-removing electric field cathode 5081, and 0 ° < α ≦ 125 °, or 45 ° ≦ α ≦ 125 °, or 60 ° ≦ α ≦ 100 °, or α ≦ 90 °.
In this embodiment, the dust removing electric field anode 5082, the auxiliary electrode 5083, and the dust removing electric field cathode 5081 form a plurality of dust removing units, so as to effectively improve the dust removing efficiency of the electric field apparatus by using the plurality of dust removing units.
In this embodiment, the substance to be treated may be dust in the form of particles or other impurities to be treated.
In this embodiment, the gas may be a product of the ultraviolet device after treating the VOCs in the engine exhaust.
The dc power supply in this embodiment may be a dc high voltage power supply. An exhaust gas ionization dust removal electric field is formed between the dust removal electric field cathode 5081 and the dust removal electric field anode 5082, and the exhaust gas ionization dust removal electric field is an electrostatic field. In the absence of the auxiliary electrode 5083, the ion flow in the electric field between the dedusting electric field cathode 5081 and the dedusting electric field anode 5082 is perpendicular to the electrode direction, and turns back and flows between the two electrodes, and the ions are consumed by turning back and forth between the electrodes. Therefore, in this embodiment, the auxiliary electrode 5083 is used to shift the relative positions of the electrodes, so that the relative imbalance between the anode 5082 of the dedusting electric field and the cathode 5081 of the dedusting electric field is formed, which causes the ion current in the electric field to deflect. In the electric field device, an auxiliary electrode 5083 forms an electric field that can provide an ion flow with directionality. The electric field device in the present embodiment is also referred to as an electric field device having an acceleration direction. The collecting rate of the particles entering the electric field along the ion flow direction is improved by nearly one time compared with the collecting rate of the particles entering the electric field along the reverse ion flow direction, so that the dust accumulation efficiency of the electric field is improved, and the power consumption of the electric field is reduced. In addition, the main reason that the dust collection efficiency of the dust collection electric field in the prior art is low is that the direction of dust entering the electric field is opposite to or perpendicular to the direction of ion flow in the electric field, so that the dust and the ion flow collide violently with each other and generate large energy consumption, and the charge efficiency is also influenced, so that the dust collection efficiency of the electric field in the prior art is reduced, and the energy consumption is increased.
When the electric field device is used for collecting dust in gas, the gas and the dust enter the electric field along the ion flow direction, so that the dust is fully charged, and the electric field consumption is low; the dust collecting efficiency of the monopole electric field can reach 99.99%. When gas and dust enter the electric field in the direction of the counter ion flow, the dust is insufficiently charged, the power consumption of the electric field is increased, and the dust collection efficiency is 40-75%. In addition, the ion flow formed by the electric field device in the embodiment is beneficial to unpowered fan fluid conveying, oxygen increasing, heat exchange and the like.
Example 20
The electric field device in the embodiment is applied to a VOCs gas treatment system in engine exhaust, and comprises a dedusting electric field cathode and a dedusting electric field anode which are respectively electrically connected with a cathode and an anode of a direct current power supply, and an auxiliary electrode is electrically connected with the cathode of the direct current power supply. In this embodiment, the auxiliary electrode and the cathode of the dedusting electric field both have negative potentials, and the anode of the dedusting electric field has positive potentials.
In this embodiment, the auxiliary electrode can be fixedly connected with the cathode of the dust removing electric field. Therefore, after the cathode of the dust removal electric field is electrically connected with the cathode of the direct current power supply, the auxiliary electrode is also electrically connected with the cathode of the direct current power supply. Meanwhile, the auxiliary electrode extends in the front-rear direction in the present embodiment.
In this embodiment, the anode of the dedusting electric field is tubular, the cathode of the dedusting electric field is rod-shaped, and the cathode of the dedusting electric field is arranged in the anode of the dedusting electric field in a penetrating manner. Meanwhile, the auxiliary electrode is also in a rod shape in the embodiment, and the auxiliary electrode and the dedusting electric field cathode form a cathode rod. The front end of the cathode bar exceeds the front end of the dust removing electric field anode forwards, and the part of the cathode bar exceeding the dust removing electric field anode forwards is the auxiliary electrode. That is, the anode of the dedusting electric field and the cathode of the dedusting electric field have the same length in the embodiment, and the anode of the dedusting electric field and the cathode of the dedusting electric field are opposite in position in the front-back direction; the auxiliary electrode is positioned in front of the dedusting electric field anode and the dedusting electric field cathode. Thus, an auxiliary electric field is formed between the auxiliary electrode and the dedusting electric field anode, and the auxiliary electric field applies backward force to the negatively charged oxygen ion flow between the dedusting electric field anode and the dedusting electric field cathode, so that the negatively charged oxygen ion flow between the dedusting electric field anode and the dedusting electric field cathode has backward moving speed. When the gas containing the substances to be treated flows into the tubular dedusting electric field anode from front to back, the oxygen ions with negative charges are combined with the substances to be treated in the process of moving towards the dedusting electric field anode and moving backwards, and because the oxygen ions have backward moving speed, the oxygen ions are combined with the substances to be treated, and strong collision cannot be generated between the oxygen ions and the substances to be treated, so that the larger energy consumption caused by the strong collision is avoided, the oxygen ions are easily combined with the substances to be treated, the charge efficiency of the substances to be treated in the gas is higher, and further under the action of the dedusting electric field anode, more substances to be treated can be collected, and the higher dedusting efficiency of the electric field device is ensured.
In this embodiment, the anode of the dust removal electric field, the auxiliary electrode and the cathode of the dust removal electric field form a plurality of dust removal units, so as to effectively improve the dust removal efficiency of the electric field device by using the plurality of dust removal units.
In this embodiment, the material to be treated may be dust in the form of particles.
Example 21
As shown in fig. 9, the electric field device of the present embodiment is applied to a system for treating VOCs in engine exhaust, and the auxiliary electrode 5083 extends in the left-right direction. In this embodiment, the length direction of the auxiliary electrode 5083 is different from the length direction of the dust removing electric field anode 5082 and the dust removing electric field cathode 5081. And the auxiliary electrode 5083 may be specifically perpendicular to the dedusting electric field anode 5082.
In this embodiment, the cathode 5081 and the anode 5082 of the dust removing electric field are electrically connected to the cathode and the anode of the dc power supply, respectively, and the auxiliary electrode 5083 is electrically connected to the anode of the dc power supply. In this embodiment, the dedusting electric field cathode 5081 has a negative potential, and the dedusting electric field anode 5082 and the auxiliary electrode 5083 each have a positive potential.
As shown in fig. 9, in the present embodiment, the dust-removing field cathode 5081 and the dust-removing field anode 5082 are opposed to each other in the front-rear direction, and the auxiliary electrode 5083 is located behind the dust-removing field anode 5082 and the dust-removing field cathode 5081. Thus, an auxiliary electric field is formed between the auxiliary electrode 5083 and the dedusting electric field cathode 5081, and the auxiliary electric field applies a backward force to the negatively charged oxygen ion stream between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081, so that the negatively charged oxygen ion stream between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081 has a backward moving speed. When gas containing substances to be treated flows into an electric field between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081 from front to back, oxygen ions with negative charges are combined with the substances to be treated in the process of moving towards the dedusting electric field anode 5082 and backwards, and the oxygen ions have backward moving speed, so that the oxygen ions are combined with the substances to be treated, strong collision cannot be generated between the oxygen ions and the substances to be treated, and therefore, the situation that the energy consumption is large due to strong collision is avoided, the oxygen ions are easily combined with the substances to be treated, the charging efficiency of the substances to be treated in the gas is high, further, under the action of the dedusting electric field anode 5082, more substances to be treated can be collected, and the high dedusting efficiency of the electric field device is guaranteed.
Example 22
As shown in fig. 10, the electric field device of the present embodiment is applied to a system for treating VOCs in engine exhaust, and the auxiliary electrode 5083 extends in the left-right direction. In this embodiment, the length direction of the auxiliary electrode 5083 is different from the length direction of the dust removing electric field anode 5082 and the dust removing electric field cathode 5081. And the auxiliary electrode 5083 may be specifically perpendicular to the dedusting electric field cathode 5081.
In this embodiment, the cathode 5081 and the anode 5082 of the dust removing electric field are electrically connected to the cathode and the anode of the dc power supply, respectively, and the auxiliary electrode 5083 is electrically connected to the cathode of the dc power supply. In this embodiment, the dedusting electric field cathode 5081 and the auxiliary electrode 5083 both have a negative potential, and the dedusting electric field anode 5082 has a positive potential.
As shown in fig. 10, in the present embodiment, the dust-removing field cathode 5081 and the dust-removing field anode 5082 are opposed to each other in the front-rear direction, and the auxiliary electrode 5083 is located in front of the dust-removing field anode 5082 and the dust-removing field cathode 5081. Thus, an auxiliary electric field is formed between the auxiliary electrode 5083 and the dedusting electric field anode 5082, and the auxiliary electric field applies a backward force to the negatively charged oxygen ion stream between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081, so that the negatively charged oxygen ion stream between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081 has a backward moving speed. When gas containing substances to be treated flows into an electric field between the dedusting electric field anode 5082 and the dedusting electric field cathode 5081 from front to back, oxygen ions with negative charges are combined with the substances to be treated in the process of moving towards the dedusting electric field anode 5082 and backwards, and the oxygen ions have backward moving speed, so that the oxygen ions are combined with the substances to be treated, strong collision cannot be generated between the oxygen ions and the substances to be treated, and therefore, the situation that the energy consumption is large due to strong collision is avoided, the oxygen ions are easily combined with the substances to be treated, the charging efficiency of the substances to be treated in the gas is high, further, under the action of the dedusting electric field anode 5082, more substances to be treated can be collected, and the high dedusting efficiency of the electric field device is guaranteed.
Example 23
The system for treating the VOCs in the engine exhaust in the embodiment comprises the electric field device in the above embodiments 19, 20, 21 or 22. The tail gas discharged by the engine firstly flows through the ultraviolet device, and the product of the tail gas treated by the ultraviolet device flows through the electric field device, so that pollutants such as dust and the like in the gas are effectively removed by utilizing the electric field device; and then, the treated gas is discharged to the atmosphere so as to reduce the influence of the tail gas of the engine on the atmosphere. In this embodiment, the engine exhaust is also referred to as an exhaust gas treatment device, the dedusting electric field cathode 5081 is also referred to as an electric field cathode, and the dedusting electric field anode 5082 is also referred to as an electric field anode.
Example 24
The engine exhaust gas dedusting system in this embodiment includes an exhaust gas temperature reduction device for reducing the exhaust gas temperature prior to the electric field device inlet. The exhaust gas cooling device in this embodiment may be in communication with the inlet of the electric field device.
As shown in fig. 11, the present embodiment provides an exhaust gas temperature reduction device, including:
the heat exchange unit 3071 is configured to exchange heat with exhaust gas of the engine to heat the liquid heat exchange medium in the heat exchange unit 3071 into a gaseous heat exchange medium.
The heat exchange unit 3071 in this embodiment may include:
the tail gas passing cavity is communicated with an exhaust pipeline of the engine and is used for the tail gas of the engine to pass through;
the medium gasification cavity is used for converting the liquid heat exchange medium and the tail gas into the gaseous heat exchange medium after heat exchange.
The medium gasification chamber in this embodiment has liquid heat transfer medium, and liquid heat transfer medium can change gaseous heat transfer medium into with tail gas after the tail gas in the tail gas through the chamber takes place the heat exchange. The tail gas passes through the chamber and realizes the collection to automobile exhaust. In this embodiment, the length directions of the medium gasification cavity and the tail gas passing cavity may be the same, that is, the axis of the medium gasification cavity coincides with the axis of the tail gas passing cavity. The medium gasification chamber in this embodiment may be located within the tail gas passing chamber or outside the tail gas passing chamber. Thus, when the automobile exhaust flows through the exhaust passing cavity, the heat carried by the automobile exhaust is transferred to the liquid in the medium gasification cavity, the liquid is heated to a boiling point, the liquid is gasified into gaseous media such as high-temperature and high-pressure steam, and the steam flows in the medium gasification cavity. In this embodiment, the medium gasification chamber may be fully covered or partially covered on the inner and outer sides of the tail gas passing chamber except for the front end thereof.
The exhaust gas cooling device in this embodiment further includes a power generation unit 3072, and the power generation unit 3072 is configured to convert heat energy of the heat exchange medium and/or heat energy of the exhaust gas into mechanical energy.
The exhaust gas cooling device in this embodiment may further include a power generation unit 3073, where the power generation unit 3073 is configured to convert the mechanical energy generated by the power generation unit 3072 into electric energy.
The operating principle of the tail gas cooling device in this embodiment is as follows: the heat exchange unit 3071 exchanges heat with the exhaust gas of the engine to heat the liquid heat exchange medium in the heat exchange unit 3071 into a gaseous heat exchange medium; the power generation unit 3072 converts the heat energy of the heat exchange medium or the heat energy of the tail gas into mechanical energy; if the power generation unit 3073 is included, the power generation unit 3073 converts the mechanical energy generated by the power generation unit 3072 into electric energy, so that power generation is realized by using tail gas of the engine, and heat and pressure carried by the tail gas are prevented from being wasted; and the heat exchange unit 3071 can also perform the functions of heat dissipation and temperature reduction on the tail gas when performing heat exchange with the tail gas, so that other tail gas purification devices and the like can be adopted to treat the tail gas, and the subsequent efficiency of treating the tail gas is improved.
In this embodiment, the heat exchange medium may be water, methanol, ethanol, oil, or alkane. The heat exchange medium is a substance capable of changing phase due to temperature, and the volume and the pressure of the heat exchange medium are correspondingly changed in the phase change process.
The heat exchange unit 3071 in this embodiment is also referred to as a heat exchanger. In this embodiment, the heat exchange unit 3071 can be a tubular heat exchange device. Design considerations for heat exchange unit 3071 include pressure bearing, reduced volume, increased heat exchange area, and the like.
As shown in fig. 11, the exhaust gas cooling device in this embodiment may further include a medium transmission unit 3074 connected between the heat exchange unit 3071 and the power generation unit 3072. The gaseous medium such as vapor formed in the medium vaporizing chamber acts on the power generation unit 3072 through the medium transfer unit 3074. The medium transfer unit 3074 includes a pressure-containing pipe.
The power generation unit 3072 in this embodiment includes a turbofan. The turbofan can convert pressure generated by gaseous media such as steam or tail gas into kinetic energy. And the turbofan comprises a turbofan shaft and at least one group of turbofan components fixed on the turbofan shaft. The turbofan assembly comprises a flow guiding fan and a power fan. When the pressure of the vapor acts on the turbofan assembly, the turbofan shaft will rotate with the turbofan assembly, thereby converting the pressure of the vapor into kinetic energy. When the power generation unit 3072 includes a turbofan, the pressure of the engine exhaust gas may also act on the turbofan to rotate the turbofan. Thus, the pressure of the steam and the pressure generated by the tail gas can be alternatively and seamlessly switched to act on the turbofan. If the power generation unit is included in the embodiment, when the turbofan rotates in the first direction, the power generation unit 3073 converts kinetic energy into electric energy to realize waste heat power generation; when the generated electric energy drives the turbofan to rotate in turn, and the turbofan rotates in the second direction, the power generation unit 3073 converts the electric energy into exhaust resistance to provide exhaust resistance for the engine, and when the exhaust brake device mounted on the engine works to generate high-temperature and high-pressure tail gas for braking the engine, the turbofan converts the braking energy into electric energy to realize exhaust braking and braking power generation of the engine.
The constant exhaust negative pressure can be generated by air suction of the high-speed turbofan, the exhaust resistance of the engine is reduced, and engine power assisting is realized. And when the power generation unit 3072 includes a turbofan, the power generation unit 3072 further includes a turbofan adjusting module, which pushes the turbofan to generate rotational inertia by using a peak value of exhaust pressure of the engine, further delays to generate negative pressure of exhaust gas, pushes the engine to suck air, reduces exhaust resistance of the engine, and increases power of the engine.
The tail gas cooling device in the embodiment can be applied to a fuel engine, such as a diesel engine or a gasoline engine. The tail gas cooling device in the embodiment can also be applied to a gas engine. Specifically, the tail gas cooling device is used for a diesel engine of a vehicle, namely the tail gas is communicated with an exhaust port of the diesel engine through a cavity.
As shown in fig. 11, the exhaust gas cooling device in this embodiment may further include a coupling unit 3075, the coupling unit 3075 is electrically connected between the power generation unit 3072 and the power generation unit 3073, and the power generation unit 3073 is coaxially coupled with the power generation unit 3072 through the coupling unit 3075.
The exhaust gas cooling device in this embodiment may further include a heat-insulating pipeline connected between the exhaust pipeline of the engine and the heat exchange unit 3071. Specifically, two ends of the heat-insulating pipeline are respectively communicated with an exhaust port of the engine system and the tail gas passing cavity, so that the high temperature of the tail gas is maintained by using the heat-insulating pipeline, and the tail gas is introduced into the tail gas passing cavity.
The tail gas cooling device in the embodiment can also comprise a fan, the fan leads air into the tail gas, and the tail gas is cooled before the inlet of the electric field device. The air may be introduced at 50% to 300%, or 100% to 180%, or 120% to 150% of the tail gas.
The tail gas cooling device in the embodiment can assist the engine system to realize the recycling of the exhaust waste heat of the engine, is beneficial to reducing the emission of greenhouse gases of the engine, is also beneficial to reducing the emission of harmful gases of the fuel engine, reduces the emission of pollutants, and ensures that the emission of the fuel engine is more environment-friendly.
The inlet air of the tail gas cooling device can be used for purifying air, and the particle content of the tail gas treated by the engine tail gas dedusting system is less than that of the air.
The tail gas cooling device can be applied to the fields of energy conservation and emission reduction of diesel engines, gasoline engines and gas engines, and is an innovative technology for improving the efficiency of the engines, saving fuel and improving the economical efficiency of the engines. The tail gas cooling device can help the automobile save fuel and improve the fuel economy; the waste heat of the engine can be recycled, and the efficient utilization of energy is realized.
In conclusion, the tail gas cooling device can realize waste heat power generation based on the automobile tail gas, the heat energy conversion efficiency is high, and the heat exchange medium can be recycled; the energy-saving and emission-reducing device can be applied to the fields of energy conservation and emission reduction of diesel engines, gasoline engines, gas engines and the like, and the waste heat of the engines is recycled, so that the economy of the engines is improved; the constant exhaust negative pressure is generated by air suction of the high-speed turbofan, so that the exhaust resistance of the engine is reduced, and the efficiency of the engine is improved. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
Example 25 UV photolysis + ionization dust removal
The embodiment provides a method for treating VOCs in engine exhaust, which comprises the following steps:
carrying out UV purification treatment on the tail gas containing VOCs to obtain a product after UV treatment on the tail gas;
and (4) performing electric field dust removal treatment on the product after the tail gas is treated by UV, and removing particulate matters in the product after the tail gas is treated by UV.
In this embodiment, the electric field dust removal processing method includes: the dust-containing gas is subjected to dust removal treatment through an ionization dust removal electric field generated by an electric field anode and an electric field cathode.
In this embodiment, the electric field dust removal processing method further includes: the ratio of the dust area of the electric field anode to the discharge area of the electric field cathode, the polar distance between the electric field anode and the electric field cathode, the length of the electric field anode and the length of the electric field cathode enable the coupling frequency of an ionization electric field to be less than or equal to 3.
In this embodiment, the electric field dust removal processing method further includes a method of providing an auxiliary electric field, including:
generating an electric field in a flow channel, the electric field being non-perpendicular to the flow channel; an included angle alpha is formed between the air inlet end of the electric field cathode and the air inlet end of the electric field anode, and alpha is 90 degrees.
1 Main test device and Material
1) VOCs stock solution (Industrial banana water)
15% of n-butyl acetate, 15% of ethyl acetate, 10-15% of n-butanol, 10% of ethanol, 5-10% of acetone, 20% of benzene and 20% of xylene;
2) ultraviolet photolysis device: UV ultraviolet lamp: u-shaped tube, 150W, 185nm +254nm mixed wavelength;
3) electric field device: the electric field device of example 1 was used;
4) VOCs concentration detection instrument and CO2A concentration detection instrument, a PM2.5 detection instrument and a temperature and humidity detection instrument;
5) air blower 2: rated air volume is 50L/min and 20L/min;
6) and 3 rotameters.
7) The PN value detection method comprises the following steps: PN value: the particle number of the solid particles is detected by using a laser dust particle counter on the light scattering principle, the gas production flow is 2.8L/min, and 5s is a sampling period.
2 main test procedures and parameters.
Referring to fig. 12, the system for treating VOCs in engine exhaust according to the present embodiment includes an ultraviolet device 4 and an electric field device 5, which are connected in sequence, where the ultraviolet device 4 includes: an air inlet 41, an air outlet 42 and an ultraviolet lamp 43.
The present embodiment adopts the electric field device 5 provided in embodiment 1, and the air outlet 42 of the ultraviolet device 4 is communicated with the electric field device inlet 51 of the electric field device 5.
Referring to fig. 12, a clean space enters an air humidification tank 1, the humidity of clean air is adjusted in the air humidification tank 1, VOCs stock solution is stored in a VOCs storage tank 2, the clean air from the air humidification tank 1 and the VOCs stock solution from the VOCs storage tank are uniformly mixed in a mixing buffer tank 3, the gas flow of the clean air and the VOCs stock solution is controlled, and the gas flow and the concentration of the uniformly mixed gas containing VOCs (VOCs gas for short) are respectively controlled to be 0.95m3/h、320mg/m3。
And (3) conveying the VOCs gas into the ultraviolet device 4 through the ultraviolet device air inlet 41 for UV purification treatment to obtain a product after UV treatment of tail gas, conveying the purified product into the electric field device 5 through the air outlet 42 for electric field dust removal treatment to remove particles in the purified product, and finally discharging the purified product from the electric field device outlet 52 of the electric field device 5.
In purpleThe external line device air inlet 41 and the electric field device outlet 52 of the electric field device 5 respectively detect the concentration content and CO of VOCs in the VOCs gas2Concentration content, PM2.5 value; the PN values of the solid particles with different sizes in the gas are detected at the gas inlet 41 of the ultraviolet device, the gas outlet 42 of the ultraviolet device and the outlet 52 of the electric field device 5, and the PN values of the solid particles with the particle diameters of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm are detected. See table 1 for the main test parameters.
TABLE 1
Figure BDA0002452423010000411
Figure BDA0002452423010000421
3 conditions and results of the experiment
Referring to FIG. 12, the initial flow rate is set to 0.95m3H, initial concentration 320mg/m3The VOCs are sequentially introduced into an ultraviolet device 4 and an electric field device 5.
After the power supply of the ultraviolet lamp in the ultraviolet device is switched on (the electric field device is not switched on temporarily), the treatment is carried out for 0 to 717 s;
starting a direct-current power supply of an electric field device at 717s, and performing an experiment for removing organic solid particles in the product after UV purification under the conditions of 5.13kV and 0.15mA electric fields;
adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification;
and adjusting the parameters of a direct current power supply of the electric field device to 9.10kV and 2.98mA at 1317s, and performing an experiment for removing the organic solid particles in the product after UV purification.
3.1 VOCs concentration variation
When the UV lamp power supply in the UV device is turned on (the electric field device is not turned on temporarily), the VOCs concentration and VOCs removal rate at the device outlet of the electric field device change with time as shown in FIG. 13, in which A is shown as the electric field deviceThe concentration of VOCs at the outlet, B, is shown as the VOCs removal efficiency, and the concentration value of VOCs in 80s of treatment is basically maintained at 320mg/m3The concentration value of (A) is not changed, and the concentration of VOCs is rapidly reduced after 80 s; after treatment for about 440s, the concentration value of VOCs is reduced to 201mg/m3The removal efficiency is as high as about 37.1%.
3.2 UV purification of VOCs product CO2Change in concentration
FIG. 14 shows the CO at the outlet of the electric field apparatus2Curve of concentration as a function of treatment time, CO2The initial concentration was 903.3mg/m3As can be seen from FIG. 14, the UV lamp is turned on and then CO is turned off2The concentration increased rapidly, and when the treatment time reached 453s, CO was added2The concentration reaches 1126mg/m3Then CO is present2The concentration is 1135mg/m3The range is kept relatively stable. It can be seen that the opening of the dust removing electric field is to CO2The influence of the amount of production of (2) is not great.
3.3 PM2.5 data analysis
FIG. 15 is a graph of PM2.5 at the device outlet of the electric field device as a function of treatment time, with the initial PM2.5 value in the VOCs gas being 25 μ g/m when the UV lamp and the electric field device are not turned on3(ii) a As can be seen from FIG. 15, when the UV device was turned on alone, PM2.5 increased rapidly, and the final PM2.5 value was maintained at 5966 μ g/m3About, i.e., PM2.5 increased by about 240 times.
Starting a direct-current power supply of the electric field device in 717s, performing an experiment for removing organic solid particles under the conditions of 5.13kV and 0.15mA electric fields, and starting the electric field device for 60s to reduce the PM2.5 value to 10 mu g/m3The PM2.5 removal efficiency is 99.8%.
Adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification; 1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing organic solid particles in the product after UV purification; under the two electric field working conditions, the PM2.5 value at the outlet of the dust removal area is 0 mu g/m3And the PM2.5 removal efficiency reaches 100 percent.
3.4 PN data analysis
When the ultraviolet device and the electric field device are not started, the PN value contents of the solid particles with different sizes in the VOCs original gas are detected, and the particle number (PN value) distribution of the solid particles with different sizes in the VOCs original gas is shown in Table 2.
After the ultraviolet device is independently started (the electric field device is not started), and the maximum purification efficiency of the VOCs is achieved, solid particle PN with various sizes in the gas at the outlet of the dust removal area is greatly increased, and the experimental data are shown in Table 3. As is clear from Table 3, PN values of the solid particles at 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm were increased to 2585933682 particles/m3122762968 pieces/m3122596749 pieces/m3120574982 pieces/m3117328622 pieces/m3112109682 pieces/m3105862049 pieces/m3Wherein, the PN values of the 2 solid particles of 5.0 μm and 10 μm are increased most obviously, and the amplification is about 15 ten thousand times.
717s, the direct-current power supply of the electric field device is turned on, and the experiment for removing the organic solid particles is carried out under the conditions of 5.13kV and 0.15mA electric fields, and the experimental data are shown in Table 4. After the electric field is turned on for 60s under the condition, PN of the gas at the outlet of the dust removal zone is reduced remarkably, as can be seen from table 4, the removal efficiencies of the solid particles with four sizes of 1.0 μm, 3.0 μm, 5.0 μm and 10 μm are all up to 100%, and the removal efficiencies of the solid particles with 23nm, 0.3 μm and 0.5 μm are 93.5%, 95.1% and 98.5%, respectively.
Adjusting the parameters of the direct-current power supply of the electric field device to 7.07kV and 0.79mA for 1017s, and carrying out an experiment for removing organic solid particles, wherein the experimental data are shown in Table 5; when the electric field was turned on for 60 seconds under these conditions, it was found from Table 5 that the solid particles at 23nm and 0.3 μm were respectively reduced to 1584849/m3And 103180/m3The removal efficiency reaches 99.9 percent, and in addition, 5 solid particles of 0.5 mu m, 1.0 mu m, 3.0 mu m, 5.0 mu m and 10 mu m reach 100 percent under the condition of the electric field.
1317s the parameters of the DC power supply of the electric field device are adjusted to 9.10kV and 2.98mA, the experiment for removing organic solid particles is carried out, and the experimental data are shown in Table 6. Under the condition of the electric field, solid particles of 23nm, 0.3 mu m and 0.5 mu m are further oneThe step is reduced to 229283 pieces/m323322/m3And 9894/m3And the removal efficiency reaches more than 99.99 percent.
TABLE 2 PN data in raw VOC gas
Figure BDA0002452423010000431
Figure BDA0002452423010000441
TABLE 3 PN data for UV at maximum VOC purification efficiency
Figure BDA0002452423010000442
TABLE 45.13 purified PN data under kV and 0.15mA electric field conditions
Figure BDA0002452423010000443
TABLE 57.07 kV and 0.79mA electric field conditions after decontamination PN data
Figure BDA0002452423010000444
TABLE 69.10 purified PN data under kV and 2.98mA electric field conditions
Figure BDA0002452423010000451
Example 26 UV photolysis + ionization dust removal
1. Electric field device: the electric field device of example 15 was used, and the other examples were the same as example 25.
2. Experimental conditions and experimental results
The initial flow rate is 0.95m3H, initial concentration 320mg/m3The VOCs are sequentially communicatedAn ultraviolet device 4 and an electric field device 5.
2.1 VOCs concentration variation
The concentration of VOCs varied in the same manner as in example 25.
2.2 UV purification of VOCs product CO2Change in concentration
UV purification of VOCs product CO2The concentration trend was the same as in example 25.
2.3 PM2.5 data analysis
When the UV device was turned on alone, the PM2.5 values in the gas tended to change with treatment time in the same manner as in example 25.
Starting a direct-current power supply of the electric field device in 717s, performing an experiment for removing organic solid particles under the conditions of 5.13kV and 0.15mA electric fields, and starting the electric field device for 60s to reduce the PM2.5 value to 0.02 mu g/m3The PM2.5 removal efficiency is 99%.
Adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification; 1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing organic solid particles in the product after UV purification; under the two electric field working conditions, the PM2.5 value at the outlet of the dust removal area is 0 mu g/m3And the PM2.5 removal efficiency reaches 100 percent.
2.4 PN data analysis
When the ultraviolet device and the electric field device are not started, the PN value contents of the solid particles with different sizes in the original gas of the VOCs are detected as shown in the table 2.
After the ultraviolet device is independently turned on (the electric field device is not turned on), and the maximum purification efficiency of the VOCs is achieved, solid particulate matter PN with various sizes in the gas at the outlet of the dust removal area is greatly increased, and the experimental data is shown in table 3 and is the same as that in example 25.
717s, the direct-current power supply of the electric field device is turned on, the experiment for removing the organic solid particles is carried out under the conditions of 5.13kV and 0.15mA electric fields, the experimental data refer to table 7, and the data in table 7 are average values of 6 sampling times. After the electric field is turned on for 60s under the condition, PN of the gas at the outlet of the dust removal area is obviously reduced, and the removal efficiency of solid particles with the sizes of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 95% as can be seen from Table 7.
Adjusting the direct-current power supply parameters of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing the organic solid particles, wherein the experimental data refer to table 8, and the data in table 8 are average values of 6 times of sampling; after the electric field is turned on for 60s under the condition, as can be seen from table 8, the removal efficiency of solid particles with the size of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99%.
1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing the organic solid particles, wherein the experimental data are shown in table 9, and the data in table 9 are average values of 6 sampling times. Under the condition of the electric field, the solid particles of 23nm, 0.3 μm and 0.5 μm further drop to 564 nm and 82/m3And 7/m3And the removal efficiency reaches 99.99 percent.
TABLE PN data after decontamination under 75.13 kV and 0.15mA electric field conditions
Figure BDA0002452423010000461
TABLE 87.07 kV and 0.79mA electric field conditions after decontamination PN data
Figure BDA0002452423010000462
TABLE PN data after purification under 99.10 kV and 2.98mA electric field conditions
Figure BDA0002452423010000463
Example 27 UV photolysis + ionization dust removal
1. Electric field device: the electric field device of example 16 was used, and the other examples were the same as example 25.
2. Experimental conditions and experimental results
The initial flow rate is 0.95m3H, initial concentration 320mg/m3The VOCs are sequentially introduced into an ultraviolet device 4,An electric field device 5.
2.1 VOCs concentration variation
The concentration of VOCs varied in the same manner as in example 25.
2.2 UV purification of VOCs product CO2Change in concentration
UV purification of VOCs product CO2The concentration trend was the same as in example 25.
2.3 PM2.5 data analysis
When the UV device was turned on alone, the PM2.5 values in the gas tended to change with treatment time in the same manner as in example 25.
Starting a direct-current power supply of the electric field device in 717s, performing an experiment for removing organic solid particles under the conditions of 5.13kV and 0.15mA electric fields, and starting the electric field device for 60s to reduce the PM2.5 value to 0.02 mu g/m3The PM2.5 removal efficiency is 99%.
Adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification; 1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing organic solid particles in the product after UV purification; under the two electric field working conditions, the PM2.5 value at the outlet of the dust removal area is 0 mu g/m3And the PM2.5 removal efficiency reaches 99.99 percent.
2.4 PN data analysis
When the ultraviolet device and the electric field device are not started, the PN value contents of the solid particles with different sizes in the original gas of the VOCs are detected as shown in the table 2.
After the ultraviolet device is independently started (the electric field device is not started), and the maximum purification efficiency of the VOCs is achieved, solid particle PN with various sizes in the gas at the outlet of the dust removal area is greatly increased, and the experimental data are shown in Table 3.
717s, the direct-current power supply of the electric field device is turned on, the experiment for removing the organic solid particles is carried out under the conditions of 5.13kV and 0.15mA electric fields, the experimental data refer to table 10, and the data in table 10 are average values of 6 times of sampling. After the electric field is turned on for 60s under the condition, PN of the gas at the outlet of the dust removal area is obviously reduced, and the removal efficiency of solid particles with the sizes of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 97 percent as can be seen from Table 12.
Adjusting the direct-current power supply parameters of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing the organic solid particles, wherein the experimental data refer to table 11, and the data in table 11 are average values of 6 times of sampling; after the electric field is turned on for 60s under the above conditions, it can be seen from Table 11 that the removal efficiency of solid particles with the size of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99%.
1317s, adjusting the parameters of the direct current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing the organic solid particles, wherein the experimental data are shown in table 12, and the data in table 12 are average values of 6 sampling times. Under the condition of the electric field, the solid particles with the particle sizes of 23nm, 0.3 mu m and 0.5 mu m are further reduced to 345 particles/m38 pieces/m3And 0 pieces/m3The removal efficiency reaches 99.99 percent.
TABLE 105.13 purified PN data under kV and 0.15mA electric field conditions
Figure BDA0002452423010000481
TABLE 117.07 kV and 0.79mA electric field conditions after decontamination PN data
Figure BDA0002452423010000482
TABLE 129.10 purified PN data under kV and 2.98mA electric field conditions
Figure BDA0002452423010000483
Example 28 UV photolysis + ionization dust removal
1. Electric field device: the electric field device of example 17 was used, and the other examples were the same as example 25.
2. Experimental conditions and experimental results
The initial flow rate is 0.95m3H, initial concentration 320mg/m3The VOCs are sequentially introduced into an ultraviolet device 4,An electric field device 5.
2.1 VOCs concentration variation
The concentration of VOCs varied in the same manner as in example 25.
2.2 UV purification of VOCs product CO2Change in concentration
UV purification of VOCs product CO2The concentration trend was the same as in example 25.
2.3 PM2.5 data analysis
When the UV device was turned on alone, the PM2.5 values in the gas tended to change with treatment time in the same manner as in example 25.
Starting a direct-current power supply of the electric field device in 717s, performing an experiment for removing organic solid particles under the conditions of 5.13kV and 0.15mA electric fields, and starting the electric field device for 60s to reduce the PM2.5 value to 0.02 mu g/m3The PM2.5 removal efficiency is 99%.
Adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification; 1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing organic solid particles in the product after UV purification; under the two electric field working conditions, the PM2.5 value at the outlet of the dust removal area is 0 mu g/m3And the PM2.5 removal efficiency reaches 99.99 percent.
2.4 PN data analysis
When the ultraviolet device and the electric field device are not started, the PN value contents of the solid particles with different sizes in the original gas of the VOCs are detected as shown in the table 2.
After the ultraviolet device is independently started (the electric field device is not started), and the maximum purification efficiency of the VOCs is achieved, solid particle PN with various sizes in the gas at the outlet of the dust removal area is greatly increased, and the experimental data are shown in Table 3.
717s, the direct-current power supply of the electric field device is turned on, the experiment for removing the organic solid particles is carried out under the conditions of 5.13kV and 0.15mA electric fields, the experimental data refer to table 13, and the data in table 13 are average values of 6 times of sampling. After the electric field is turned on for 60s under the condition, PN of the gas at the outlet of the dust removal area is obviously reduced, and the removal efficiency of solid particles with the sizes of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99% as can be seen from Table 13.
Adjusting the parameters of the direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing the organic solid particles, wherein the experimental data refer to table 14, and the data in table 14 are average values of 6 times of sampling; after the electric field is turned on for 60s under the conditions, as can be seen from table 14, the removal efficiency of solid particles with the size of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99.9%.
1317s the parameters of the dc power supply of the electric field device were adjusted to 9.10kV and 2.98mA for the experiment of removing organic solid particles, the experimental data are shown in table 15, and the data in table 15 are the average values of 6 samplings. Under the condition of the electric field, the solid particles of 23nm, 0.3 mu m and 0.5 mu m further drop to 435 particles/m 30, m3And 0 pieces/m3The removal efficiency is 99.99%.
TABLE 135.13 purified PN data under kV and 0.15mA electric field conditions
Figure BDA0002452423010000491
TABLE 147.07 kV and 0.79mA electric field conditions after decontamination PN data
Figure BDA0002452423010000492
TABLE 159.10 purified PN data under kV and 2.98mA electric field conditions
Figure BDA0002452423010000493
Figure BDA0002452423010000501
Example 29 UV photolysis + ionization dust removal
1. Electric field device: the electric field device of example 18 (reduced coupling, pole pitch) was used, and the other examples were the same as example 25.
2. Experimental conditions and experimental results
The initial flow rate is 0.95m3H, initial concentration 320mg/m3The VOCs are sequentially introduced into an ultraviolet device 4 and an electric field device 5.
3.1 VOCs concentration variation
The concentration of VOCs varied in the same manner as in example 25.
3.2 UV purification of VOCs product CO2Change in concentration
UV purification of VOCs product CO2The concentration trend was the same as in example 25.
3.3 PM2.5 data analysis
When the UV device was turned on alone, the PM2.5 values in the gas tended to change with treatment time in the same manner as in example 25.
Starting a direct-current power supply of the electric field device in 717s, performing an experiment for removing organic solid particles under the conditions of 5.13kV and 0.15mA electric fields, and starting the electric field device for 60s to reduce the PM2.5 value to 0.002 mug/m3The PM2.5 removal efficiency is 99.9%.
Adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification; 1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing organic solid particles in the product after UV purification; under the two electric field working conditions, the PM2.5 value at the outlet of the dust removal area is 0 mu g/m3And the PM2.5 removal efficiency reaches 99.99 percent.
3.4 PN data analysis
When the ultraviolet device and the electric field device are not started, the PN value contents of the solid particles with different sizes in the original gas of the VOCs are detected as shown in the table 2.
After the ultraviolet device is independently started (the electric field device is not started), and the maximum purification efficiency of the VOCs is achieved, solid particle PN with various sizes in the gas at the outlet of the dust removal area is greatly increased, and the experimental data are shown in Table 3.
717s, the direct-current power supply of the electric field device is turned on, the experiment for removing the organic solid particles is carried out under the conditions of 5.13kV and 0.15mA electric fields, the experimental data refer to table 16, and the data in table 16 are average values of 6 times of sampling. After the electric field is turned on for 60s under the condition, PN of the gas at the outlet of the dust removal area is obviously reduced, and the removal efficiency of solid particles with the sizes of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99% as can be seen from Table 16.
Adjusting the direct-current power supply parameters of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing the organic solid particles, wherein the experimental data refer to table 17, and the data in table 17 are average values of 6 times of sampling; after the electric field is turned on for 60s under the conditions, as can be seen from Table 17, the removal efficiency of solid particles with the size of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99%.
1317s the parameters of the dc power supply of the electric field device were adjusted to 9.10kV and 2.98mA for the experiment of removing organic solid particles, the experimental data are shown in table 18, and the data in table 18 are the average values of 6 samplings. Under the condition of the electric field, the solid particles of 23nm, 0.3 mu m and 0.5 mu m further drop to 323 particles/m 30, m3And 0 pieces/m3And the removal efficiency reaches 99.99 percent.
TABLE 165.13 purified PN data under kV and 0.15mA electric field conditions
Figure BDA0002452423010000511
TABLE 177.07 kV and 0.79mA electric field conditions after decontamination PN data
Figure BDA0002452423010000512
TABLE 189.10 purified PN data under kV and 2.98mA electric field conditions
Figure BDA0002452423010000513
Example 30 UV photolysis + ionization dust removal
1. Electric field device: the electric field device of example 21 was used, and the same procedure as in example 25 was repeated.
2. Experimental conditions and experimental results
The initial flow rate is 0.95m3H, initial concentration 320mg/m3The VOCs are sequentially introduced into an ultraviolet device 4 and an electric field device 5.
2.1 VOCs concentration variation
The concentration of VOCs varied in the same manner as in example 25.
2.2 UV purification of VOCs product CO2Change in concentration
UV purification of VOCs product CO2The concentration trend was the same as in example 25.
2.3 PM2.5 data analysis
When the UV device was turned on alone, the PM2.5 values in the gas tended to change with treatment time in the same manner as in example 25.
Starting a direct-current power supply of the electric field device in 717s, performing an experiment for removing organic solid particles under the conditions of 5.13kV and 0.15mA electric fields, and starting the electric field device for 60s to reduce the PM2.5 value to 0.21 mu g/m3The PM2.5 removal efficiency is 99%.
Adjusting the parameters of a direct-current power supply of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing organic solid particles in the product after UV purification; 1317s, adjusting the parameters of the direct-current power supply of the electric field device to 9.10kV and 2.98mA, and performing an experiment for removing organic solid particles in the product after UV purification; under the two electric field working conditions, the PM2.5 value at the outlet of the dust removal area is 0.017 mu g/m3And the PM2.5 removal efficiency reaches 99.9 percent.
2.4 PN data analysis
When the ultraviolet device and the electric field device are not started, the PN value contents of the solid particles with different sizes in the original gas of the VOCs are detected as shown in the table 2.
After the ultraviolet device is independently started (the ionization dust removal device is not started), and the maximum purification efficiency of VOCs is achieved, solid particulate matter PN with various sizes in gas at the outlet of the dust removal area is greatly increased, and experimental data are shown in Table 3.
717s, the direct-current power supply of the electric field device is turned on, the experiment for removing the organic solid particles is carried out under the conditions of 5.13kV and 0.15mA electric fields, the experimental data refer to table 19, and the data in table 19 are average values of 6 times of sampling. After the electric field is turned on for 60s under the condition, PN of the gas at the outlet of the dust removal area is obviously reduced, and the removal efficiency of solid particles with the sizes of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99% as can be seen from Table 19.
Adjusting the direct-current power supply parameters of the electric field device to 7.07kV and 0.79mA at 1017s, and carrying out an experiment for removing the organic solid particles, wherein the experimental data refer to table 20, and the data in table 20 are average values of 6 times of sampling; after the electric field is turned on for 60s under the condition, as can be seen from table 20, the removal efficiency of solid particles with the size of 23nm, 0.3 μm, 0.5 μm, 1.0 μm, 3.0 μm, 5.0 μm and 10 μm reaches 99.9%.
1317s the parameters of the dc power supply of the electric field device were adjusted to 9.10kV and 2.98mA for the experiment of removing organic solid particles, the experimental data are shown in table 21, and the data in table 21 are the average values of 6 samplings. Under the condition of the electric field, the solid particles with the particle sizes of 23nm, 0.3 mu m and 0.5 mu m further drop to 5333 particles/m 30, m3And 5/m3The removal efficiency reaches 99.99 percent.
TABLE 195.13 purified PN data under kV and 0.15mA electric field conditions
Figure BDA0002452423010000521
TABLE 207.07 kV and 0.79mA electric field conditions after decontamination PN data
Figure BDA0002452423010000522
TABLE 219.10 purified PN data under kV and 2.98mA electric field conditions
Figure BDA0002452423010000531
Example 31 UV + molecular Sieve + activated carbon Combined purification (hereinafter referred to as "Combined purification")
The embodiment provides a method for treating VOCs in engine exhaust, which comprises the following steps: carrying out UV purification treatment on the tail gas to obtain a product after UV treatment on the tail gas; and adsorbing and purifying the product after the UV treatment of the tail gas, and then carrying out electric field dust removal treatment. The main experimental device flow diagram of this example is shown in fig. 16.
1 Main test device and consumable
VOCs stock solution (Industrial banana water)
15% of n-butyl acetate, 15% of ethyl acetate, 10-15% of n-butanol, 10% of ethanol, 5-10% of acetone, 20% of benzene and 20% of xylene;
UV ultraviolet lamp
U-shaped tube, 150W, 185nm +254nm mixed wavelength
c. Adsorbent and process for producing the same
21AE hydrophobic molecular sieve;
industrial honeycomb activated carbon;
VOCs instrument, CO2Instrument, O3Instrument, PM2.5 instrument, humiture instrument
2 sorbent base product parameters see table 22.
TABLE 22
Figure BDA0002452423010000532
3 Combined purification VOCs test data
Referring to fig. 13, the system for treating VOCs in engine exhaust according to this embodiment includes an ultraviolet device 4 and an adsorption device 6, which are connected in sequence, where the ultraviolet device 4 includes: an air inlet 41, an air outlet 42 and an ultraviolet lamp 43. The adsorption device 6 comprises a gas inlet 61 and a gas outlet 62, and the gas inlet 61 of the adsorption device 6 is communicated with the gas outlet 42 of the ultraviolet device 4.
Clean space gets into air humidifying jar 1 in this embodiment, adjust clean air's humidity in air humidifying jar 1, the VOCs stoste is stored in VOCs storage tank 2, with the clean air who comes from air humidifying jar 1 and the VOCs stoste that comes from in the VOCs storage tank mixing in mixing buffer tank 3, the gas flow of control clean air and VOCs stoste, the VOCs gas after will mixing the homogeneous lets in ultraviolet device 4 in proper order, adsorption equipment 6, at first purify partly VOCs molecule through UV photodissociation photo-oxidation, remaining VOCs molecule utilizes the physical adsorption purification of molecular sieve + active carbon that contains porous structure to detach, the gaseous emission of passing through the adsorption equipment export of final purification, reach the gaseous purpose that purifies of VOCs.
3.1 concentration of 614mg/m of combined purification low VOCs3Analysis of experimental data
3.1.1 fixed parameters
The ultraviolet device 4 was equipped with a 150W U-shaped ultraviolet lamp 43, and the adsorption device 6 was filled with 25.1g of molecular sieves 63 and 30.8g of active metal 64, respectively. The humidity of the VOCs gas entering the inlet 41 of the ultraviolet device 4 was controlled to 90% RH or higher by bubbling clean air. Regulating the gas flow of clean air and the stock solution of VOCs, and controlling the gas flow and concentration of VOCs to be 0.9m3H and 614mg/m3See 23 for other experimental parameters.
TABLE 23
Temperature of air 18℃ Humidity of air 70％RH Atmospheric pressure Atmospheric pressure
UV lamp wavelength 185+254nm UV lamp tube power 150W Residence time in the purification zone 18.2s
VOCs stock gas flow <0.04m3/h Air gas flow 1.1m3/h VOCs flow at outlet of buffer tank 0.9m3/h
21AE molecular sieve loading 25.1g 21AE molecular sieve weight gain 2.9g Initial PM2.5 at inlet of photolysis zone 79μg/m3
Loading of activated carbon 30.8g Weight gain of activated carbon 0.5g Final PM2.5 at the outlet of adsorption zone 6096μg/m3
Buffer tank gas humidity >90％RH
3.1.2 purification Process VOCs variation data at the outlet of each purification Unit
Concentration of 3.1.2.1 VOCs
Fig. 17 is a graph showing the time-dependent changes of the concentrations of the VOCs at the air inlet 41, the air outlet 42 and the air outlet 62 of the ultraviolet device 4 and the adsorption device 6 when purifying low VOCs, wherein a is the concentration of the VOCs at the outlet of the buffer tank, B is the concentration of the VOCs at the air outlet of the ultraviolet device, and C is the concentration of the VOCs at the air outlet of the adsorption device. As can be seen from FIG. 17, from the curve of the concentration of VOCs at the outlet 62 of the adsorption apparatus 6, the concentration of VOCs at the outlet of the adsorption zone stabilized at 6-9mg/m3 within 0s-600s at the beginning of the combined purification test, during which the combined purification efficiency reached 98.5%.
At about 800s (13min), the concentration of 62VOCs at the outlet of the adsorption device 6 is 30mg/m3(when the concentration value of VOCs is set to be 5% of the original concentration, the adsorbent penetrates), the adsorbent penetrates, and before penetration, the combined purification efficiency is at least more than 95%;
when the combined purification time exceeds the penetration time, the combined purification efficiency gradually decreases, and the concentration of the gas outlet 62 of the adsorption device 6 rises to 197mg/m at 7200s (2 hours)3At this time, the concentration of the gas outlet of the ultraviolet device was 219mg/m3That is, the concentrations before and after adsorption and purification are substantially equal, the molecular sieve + activated carbon combined adsorbent is saturated and ineffective, and cannot adsorb and purify the VOCs, and the saturated adsorbent needs to be replaced and the VOCs needs to be desorbed and regenerated in advance.
In the whole combined purification process, from the beginning of purification to the saturation of the adsorbent in the adsorption device, the total time is about 7200s, and the statistics of the test data can obtain that the purification efficiency of the VOCs of the UV purification device is basically kept about 40.9%.
3.1.2.2 purifying process and each purifying unit outlet CO2Change data
FIG. 18 shows the CO at the inlet, outlet and outlet of the ultraviolet device during purification of low VOCs concentration2Curve of concentration over timeWherein A is shown as CO at the outlet of the buffer tank2Concentration, B, is shown as CO at the outlet of the UV device2Concentration, C, as CO at the outlet of the gas outlet of the adsorption unit2And (4) concentration. As can be seen from FIG. 18, CO at the inlet of the ultraviolet device2The concentration is kept at 852mg/m as a whole3Average level of (a), CO at the outlet of the ultraviolet device after reaching the maximum VOCs purification efficiency of UV2The concentration is basically maintained at a relatively stable level, namely 1284mg/m3，CO2The new generation rate after UV purification is stabilized at about 50.7%.
CO at the outlet of the adsorption device2The concentration reaches the maximum value of 1584mg/m after 360s3And then maintained at a relatively constant level of 1472mg/m3I.e. CO purified in combination2The new generation rate is stabilized at about 72.8%.
Comparing CO at outlets of UV purification device and adsorption device2The concentration and the rate of formation of the new gas of (A) are shown as the CO in the adsorption apparatus2The concentration and the new generation rate of (2) are still greatly increased due to VOCs and O at the outlet of the UV unit3And H2O can be adsorbed on the outer surfaces of the molecular sieve and the activated carbon and the inner surfaces of the pore passages after entering the adsorption zone, and the catalytic oxidation decomposition of VOCs is continued to generate CO2, and the gas can enter the electric field device for dedusting to further purify the VOCs in the gas.
3.1.2.3 comparison of PM2.5 data at the beginning of Combined decontamination and at the end of Combined decontamination
0.9m before the start of the formal combined cleanup experiment3H and 614mg/m3Has a PM2.5 value of 79 [ mu ] g/m in VOCs gas3And after the 7200s purification experiment, the PM2.5 value in the gas at the outlet of the adsorption device is increased to 6096 mu g/m3PM2.5 increased nearly 77-fold.
On the one hand, the VOCs are decomposed to generate CO in the processes of UV photolysis and photooxidation2And photopolymerization occurs, so that the VOCs molecules polymerize to generate organic particles with high molecular weight, and the organic particles are dispersed in the gas.
3.2 Combined purification with high VOCs concentration of 1105mg/m3Analysis of experimental data
3.2.1 Experimental fixed parameters
Regulating the gas flow of clean air and the stock solution of VOCs, and controlling the gas flow and concentration of VOCs to be 0.9m3H and 1105mg/m3See table 24 for specific parameters.
Watch 24
Temperature of air 19℃ Humidity of air 70％RH Atmospheric pressure Atmospheric pressure
UV lamp wavelength 185nm+254 UV lamp tube power 150W UV purification zone residence time 18.2S
VOCs bulk gas stream <0.04m3/h Air gas flow 1.1m3/h Buffer tank outlet VOCs stream 0.9m3/h
21AE molecular sieve loading 23.6g 21AE molecular sieve 4.0g Photolysis zone entrance initiation 17μg/m3
Loading of activated carbon 30.0g Weight gain of activated carbon 1.1g Final outlet of adsorption zone 5580
Buffer tank gas humidity >90％RH
3.2.2 purification Process VOCs variation data at the outlet of each purification Unit
Concentration of 3.2.2.1 VOCs
Fig. 19 is a graph showing the time-dependent changes in the concentrations of VOCs at the inlet, outlet and outlet of the ultraviolet light unit during purification of high VOCs, wherein a is the concentration of VOCs at the outlet of the buffer tank, B is the concentration of VOCs at the outlet of the ultraviolet light unit, and C is the concentration of VOCs at the outlet of the adsorption unit. As can be seen from FIG. 19, from the change curve of the concentration C7 of VOCs at the outlet of the adsorption zone, the concentration values of VOCs at the outlet of the adsorption zone were stable from 0s to 600s at the beginning of the combined purification testSet at 8-19mg/m3The combined purification efficiency during this period reaches 98.3%.
The concentration of VOCs at the outlet of the adsorption zone is 55mg/m at about 1020s3(when the concentration value of VOCs is set to be 5% of the original concentration, the adsorbent penetrates), the adsorbent penetrates, and before penetration, the combined purification efficiency is at least over 94.7%;
when the combined purification time exceeds the breakthrough time, the combined purification efficiency gradually decreases, and the outlet concentration C7 of the adsorption zone rises to 451mg/m at 7200s (2 hours)3At this time, the UV device outlet concentration C5 was 456mg/m3The molecular sieve and activated carbon combined adsorbent is saturated and ineffective, and can not play a role in adsorbing and purifying VOCs any more, the combined purification efficiency is reduced to 41.1%, and only the UV photolysis device can play a purification role.
In the whole combined purification process, from the beginning of purification to the saturation of the adsorbent in the adsorption device, the total time is about 7200s, and the statistics of the test data can obtain that the purification efficiency of the VOCs of the UV purification device is basically kept at about 41.1%.
3.2.2.2 purification Process Each purification Unit Outlet CO2Change data
FIG. 20 shows the CO at the inlet, outlet and outlet of the ultraviolet device during purification of high VOCs concentration2Concentration profile over time, where A is shown as CO at the outlet of the buffer tank2Concentration, B, is shown as CO at the outlet of the UV device2Concentration, C, as CO at the outlet of the gas outlet of the adsorption unit2And (4) concentration. As can be seen in FIG. 20, the CO at the inlet of the UV device2The concentration is kept at 882.5mg/m3Average level of (a), CO at the outlet of the ultraviolet device after reaching the maximum VOCs purification efficiency of UV2The concentration is basically maintained at a relatively stable level, namely 1531mg/m3The new generation rate of CO2 after UV purification is stabilized at about 73.6%.
CO at the outlet of the adsorption device2The concentration reached a maximum of 1748mg/m after 360s3Then kept at a relatively stable level of 1679mg/m3I.e. CO purified in combination2The new generation rate is stabilized at about 90.3%.
Comparing CO at outlets of UV purification device and adsorption device2The concentration and the rate of formation of the new gas of (A) are shown as the CO in the adsorption apparatus2The concentration and the newly generated rate of (C) are still greatly increased due to VOCs and O discharged from the ultraviolet ray apparatus3、H2After entering the adsorption zone, O can be adsorbed on the outer surfaces and the inner surfaces of the pore passages of the molecular sieve and the activated carbon, and the catalytic oxidation decomposition of VOCs is continuously carried out to generate CO2And further purifying VOCs in the waste gas.
3.2.2.3 comparison of PM2.5 data at the beginning of Combined decontamination and at the end of Combined decontamination
0.9m before the start of the formal combined cleanup experiment3H and 1105mg/m3Has a PM2.5 value of 17 [ mu ] g/m in VOCs gas3And after the 7200s purification experiment is finished, the PM2.5 value in the gas at the outlet of the adsorption device is increased to 5580 mu g/m3PM2.5 increased nearly 300-fold; meanwhile, yellow oily liquid is generated at the lower end of a 21AE molecular sieve adsorption column of the adsorption device.
Indicating that VOCs are polymerized in different degrees by photopolymerization during UV treatment, and products are also different: part of the products are organic solid particles with high molecular weight, can be suspended in gas and are taken out of the UV purification unit along with the gas flow to be discharged; the other part is deposited on the inner surface of the pipe in a liquid state.
In conclusion, the present invention effectively overcomes various disadvantages of the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (5)

1. A system for treating gases of VOCs in engine exhaust, comprising:
an inlet, an outlet, and a flow channel between the inlet and the outlet;
the ultraviolet device and the electric field device are sequentially arranged along the flow channel from the inlet to the outlet;
the electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field;
the electric field device also comprises an auxiliary electric field unit which is used for generating an auxiliary electric field which is not parallel to the ionization dust removal electric field.
2. A system for treating gases of VOCs in engine exhaust, comprising:
an inlet, an outlet, and a flow channel between the inlet and the outlet;
the ultraviolet device and the electric field device are sequentially arranged along the flow channel from the inlet to the outlet;
the electric field device comprises: the device comprises an electric field device inlet, an electric field device outlet, an electric field cathode and an electric field anode, wherein the electric field cathode and the electric field anode are used for generating an ionization dust removal electric field;
the electric field device further comprises an auxiliary electric field unit, the ionization dust removal electric field comprises a flow channel, and the auxiliary electric field unit is used for generating an auxiliary electric field which is not perpendicular to the flow channel.
3. A method for treating VOCs gas in engine tail gas comprises the following steps:
carrying out UV treatment on the tail gas of the engine to obtain a product after the UV treatment;
carrying out electric field dust removal treatment on the UV-treated product to remove particles in the UV-treated product;
the electric field dust removal treatment also comprises a method for accelerating gas, and comprises the following steps:
passing engine exhaust through a flow path;
an electric field is generated in the flow channel, the electric field being non-perpendicular to the flow channel, the electric field including an inlet and an outlet.
4. The method for treating the gases of the VOCs in the engine exhaust according to any one of claims 3 or 4, wherein the method for treating the gases of the VOCs in the engine exhaust further comprises performing adsorption treatment on a product obtained after UV treatment on the engine exhaust, and then performing electric field dust removal treatment.
5. The method for treating VOCs in engine exhaust according to claim 5, wherein the adsorbent used in the adsorption treatment is activated carbon and/or molecular sieve.
CN202010296602.1A 2019-04-25 2020-04-15 System and method for treating VOCs gas in engine tail gas Pending CN113522023A (en)

Priority Applications (20)

Application Number Priority Date Filing Date Title
CN202010296602.1A CN113522023A (en) 2020-04-15 2020-04-15 System and method for treating VOCs gas in engine tail gas
PCT/CN2020/086856 WO2020216361A1 (en) 2019-04-25 2020-04-24 Vocs gas treatment system and method in engine exhaust gas
CN202080030932.4A CN113748258A (en) 2019-04-25 2020-04-24 System and method for treating VOCs gas in engine tail gas
PCT/CN2020/086863 WO2020216367A1 (en) 2019-04-25 2020-04-24 Apparatus and method for treating vocs gas
CN202080030898.0A CN113727781A (en) 2019-04-25 2020-04-24 VOCs gas treatment device and method
CN202080030900.4A CN113710881A (en) 2019-04-25 2020-04-24 System and method for treating VOCs gas in engine tail gas
CN202090000500.4U CN216974977U (en) 2019-04-25 2020-04-24 VOCs gas treatment system in engine tail gas
CN202080030946.6A CN113748259A (en) 2019-04-25 2020-04-24 System and method for treating VOCs gas in engine tail gas
PCT/CN2020/086864 WO2020216368A1 (en) 2019-04-25 2020-04-24 Apparatus and method for treating vocs gas
PCT/CN2020/086865 WO2020216369A1 (en) 2019-04-25 2020-04-24 Voc gas treatment apparatus and method
PCT/CN2020/086866 WO2020216370A1 (en) 2019-04-25 2020-04-24 Voc gas treatment device and method
PCT/CN2020/086858 WO2020216363A1 (en) 2019-04-25 2020-04-24 System and method for processing voc gas in engine tail gas
CN202090000499.5U CN218235209U (en) 2019-04-25 2020-04-24 Electric field device and VOCs gas treatment device
PCT/CN2020/086857 WO2020216362A1 (en) 2019-04-25 2020-04-24 System and method for treating voc gas in engine exhaust gas
CN202080030940.9A CN113747976A (en) 2019-04-25 2020-04-24 VOCs gas treatment device and method
CN202080030899.5A CN113710350A (en) 2019-04-25 2020-04-24 VOCs gas treatment device and method
PCT/CN2020/086861 WO2020216365A1 (en) 2019-04-25 2020-04-24 System and method for treating vocs gas in engine exhaust gas
PCT/CN2020/086862 WO2020216366A1 (en) 2019-04-25 2020-04-24 Vocs gas treatment apparatus and method
PCT/CN2020/086860 WO2020216364A1 (en) 2019-04-25 2020-04-24 System and method for processing voc gas in engine tail gas
CN202080030938.1A CN113710366A (en) 2019-04-25 2020-04-24 System and method for treating VOCs gas in engine tail gas

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210310387A1 (en) * 2018-10-22 2021-10-07 Shanghai Bixiufu Enterprise Management Co., Ltd. Exhaust gas treatment system and method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210310387A1 (en) * 2018-10-22 2021-10-07 Shanghai Bixiufu Enterprise Management Co., Ltd. Exhaust gas treatment system and method

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