CN106582286B - Flue gas purification device and method - Google Patents

Flue gas purification device and method Download PDF

Info

Publication number
CN106582286B
CN106582286B CN201710058501.9A CN201710058501A CN106582286B CN 106582286 B CN106582286 B CN 106582286B CN 201710058501 A CN201710058501 A CN 201710058501A CN 106582286 B CN106582286 B CN 106582286B
Authority
CN
China
Prior art keywords
absorbent
flue gas
flue
outlet
scr reactor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201710058501.9A
Other languages
Chinese (zh)
Other versions
CN106582286A (en
Inventor
张哲然
王建春
张原�
郭厚焜
林春源
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LONJING ENVIRONMENT TECHNOLOGY CO LTD
Original Assignee
LONJING ENVIRONMENT TECHNOLOGY CO LTD
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by LONJING ENVIRONMENT TECHNOLOGY CO LTD filed Critical LONJING ENVIRONMENT TECHNOLOGY CO LTD
Priority to CN201710058501.9A priority Critical patent/CN106582286B/en
Publication of CN106582286A publication Critical patent/CN106582286A/en
Application granted granted Critical
Publication of CN106582286B publication Critical patent/CN106582286B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8603—Removing sulfur compounds
    • B01D53/8609—Sulfur oxides
    • 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
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/75—Multi-step processes
    • 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
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8659—Removing halogens or halogen compounds
    • 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
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/90—Injecting reactants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/003—Arrangements of devices for treating smoke or fumes for supplying chemicals to fumes, e.g. using injection devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/006—Layout of treatment plant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
    • F23J15/04—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material using washing fluids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/30—Alkali metal compounds
    • B01D2251/304—Alkali metal compounds of sodium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/40—Alkaline earth metal or magnesium compounds
    • B01D2251/404—Alkaline earth metal or magnesium compounds of calcium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/204—Inorganic halogen compounds
    • B01D2257/2045—Hydrochloric acid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/204—Inorganic halogen compounds
    • B01D2257/2047—Hydrofluoric acid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/30—Sulfur compounds
    • B01D2257/302—Sulfur oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2215/00—Preventing emissions
    • F23J2215/20—Sulfur; Compounds thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2215/00—Preventing emissions
    • F23J2215/30—Halogen; Compounds thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2219/00—Treatment devices
    • F23J2219/10—Catalytic reduction devices

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Treating Waste Gases (AREA)

Abstract

The invention provides a flue gas purification device, which also comprises: the device comprises a first-stage absorbent injection device, a second-stage absorbent injection device, an absorbent bin and an absorbent quantitative supply device; a first-stage absorbent injection device is arranged on the inlet flue of the SCR reactor; and a second-stage absorbent injection device is arranged on the outlet flue of the SCR reactor. The method and the device provided by the invention are used for treating SO in flue gas 3 The method has the advantages that sectional control is carried out, HCl and HF in the flue gas are synchronously removed, meanwhile, the adverse effects of abrasion, dust deposition, blockage and the like on the SCR catalyst and an air preheater caused by adding a large amount of absorbent in a single stage are avoided, the absorbent and the flue gas are fully and uniformly mixed, and the absorbent is prevented from settling; the utilization rate of the absorbent and the removal efficiency of the system are improved.

Description

Flue gas purification device and method
Technical Field
The invention relates to the technical field of environmental management, in particular to a flue gas purification device and a flue gas purification method.
Background
In the combustion process of coal, sulfur element, chlorine element and fluorine element in the coal can be converted into flue gas and generate SO 2 HCl and HF. Typically about 1% SO 2 Will be converted into SO 3 ，SO 3 The concentration is relatively high; the concentrations of HCl and HF are generally low. The field of flue gas purification of thermal power plants is generally only used for SO in flue gas 2 、NO X And dust and other main index pollutants to treat SO 3 Contaminants such as HCl, HF, etc. are not effectively controlled.
Reducing agent NH sprayed in SCR reaction 3 With SO in flue gas 3 Will generate NH 4 HSO 4 If the SCR reaction temperature is operated at a lower temperature for a long time, NH may be caused 4 HSO 4 Clogging on the catalyst affects the removal efficiency and service life of the catalyst and increases the running resistance. SCR catalyst can reduce NO X Emission, but the SCR catalyst contains V 2 O 5 Component (b), inevitably will be part of SO in the flue gas 2 Conversion of SO 3 (by 0.5% to 1%), and NH 3 NH formed by the reaction 4 HSO 4 The dust is attached to the surface of a heat exchange element of the air preheater, so that the dust is accumulated and the air preheater is blocked. SO in flue gas 3 HCl and HF will corrode flues and equipment after condensation. SO 3 After being discharged to the atmospheric environment, colored smoke plume can be formed.
Chinese patent with application number CN105148709A discloses a flue gas treatment method, which comprises the steps of sequentially carrying out SCR denitration treatment and desulfurization treatment on flue gas generated by coal combustion, wherein before the SCR denitration treatment, the flue gas is contacted with an alkaline solution in an atomized state to carry out HF, HCl and SO in the flue gas 3 The gas is converted into solid salt; the alkaline absorbent may be selected from Na 2 CO 3 、NaHCO 3 And NaOH. The method comprises the step of spraying an alkaline solution into flue gas before SCR denitration treatment for removing SO in the flue gas 3 HCl and HF; and will also contain Cl - 、F - The waste water is sprayed into the SCR denitration device for treatment, and the alkali liquor consumption is large. A large amount of alkali liquor is sprayed into flue gas and is converted into solid salt, and then the solid salt is attached to the surface of the SCR catalyst, so that the catalyst is easily blocked, the catalyst is poisoned, and the removal efficiency and the service life of the catalyst are influenced. Therefore, the prior art generally adopts a single-stage absorbent adding mode, so that the utilization rate of the absorbent is low, and the removal efficiency is limited; but also easily brings certain restriction or influence to the operation of the device.
Disclosure of Invention
The invention aims to provide a flue gas purification device and a flue gas purification method, and the flue gas purification device can efficiently remove SO 3 HCl and HF, and can prevent the equipmentThe service life of the catalyst is prolonged.
In view of this, the present application provides a flue gas cleaning device, comprising: the system comprises an SCR reactor inlet flue, an SCR reactor outlet flue, an air preheater and an air preheater outlet flue; the outlet end of the boiler is provided with the SCR reactor inlet flue, the outlet end of the SCR reactor inlet flue is provided with the SCR reactor, the outlet end of the SCR reactor is provided with the SCR reactor outlet flue, the outlet of the SCR reactor outlet flue is provided with the air preheater, and the outlet end of the air preheater is provided with the air preheater outlet flue; it is characterized in that the flue gas purification device further comprises: the device comprises a first-stage absorbent spraying device, a second-stage absorbent spraying device, an absorbent bin and an absorbent quantitative supply device;
a first-stage absorbent injection device is arranged on the inlet flue of the SCR reactor;
a second-stage absorbent spraying device is arranged on the flue at the outlet of the SCR reactor;
the lower end of the absorbent bin is provided with an absorbent quantitative supply device;
and the outlet end of the absorbent quantitative supply device is respectively connected with the inlet ends of the first-stage absorbent injection device and the second-stage absorbent injection device.
Preferably, the flue gas purification device further comprises an atomization humidification device, and the outlet flue of the air preheater is provided with the atomization humidification device.
Preferably, the flue gas purification device further comprises a water tank, wherein a water pump is arranged at the outlet end of the water tank, and the water pump is connected with the inlet end of the atomization spraying device.
Preferably, the SCR outlet flue is provided with an absorbent suspension gas supporting device, an included angle between a suspension gas supporting hole of the suspension gas supporting device and the flue is 70-110 degrees, and the absorbent suspension gas supporting device is arranged in a horizontal flue at the downstream of the second-stage absorbent injection device.
Preferably, the flue at the outlet of the air preheater is provided with an absorbent suspension gas supporting device, and the included angle between the suspension gas supporting hole of the suspension gas supporting device and the flue is 70-110 degrees.
Preferably, a plurality of injection points are arranged on the first-stage absorbent injection device and the second-stage absorbent injection device respectively.
Preferably, a flue gas turbulence device is further arranged on the inlet flue of the SCR reactor, and the flue gas turbulence device is arranged on the upstream of the first-stage absorbent injection device.
Preferably, the flue gas turbulence device is a ring-type swirling flow turbulence device which is composed of an inner ring, an outer ring and middle swirling vanes; the included angle between the swirl vanes and the horizontal plane is 20-60 degrees, and the included angle between the flue gas turbulent flow device and the flow direction of the flue gas is 60-90 degrees.
The application also provides a flue gas purification method, which comprises the following steps:
mixing flue gas generated by combustion in a boiler with an absorbent to obtain primarily purified flue gas;
the flue gas which is preliminarily purified enters an SCR reactor for reaction to obtain the flue gas after the reaction;
mixing the reacted flue gas with the absorbent again, and discharging the flue gas after heat exchange to obtain the deeply purified flue gas.
Preferably, the heat exchange device further comprises:
atomizing and humidifying the flue gas after heat exchange.
Preferably, in the step of obtaining the preliminarily purified flue gas, the absorbent and SO in the flue gas 3 The molar ratio of (1-1.5): 1; in the step of obtaining the deeply purified flue gas, the SO in the absorbent and the flue gas 3 The molar ratio of (1-3): 1.
preferably, in the step of obtaining the preliminarily purified flue gas, the absorbent is conveyed by taking fluidized wind or compressed air as a carrier; in the step of obtaining the deeply purified flue gas, the absorbent is conveyed by taking fluidized wind or compressed air as a carrier.
Preferably, in the step of obtaining the preliminarily purified flue gas, the absorbent is one or more selected from quick lime, slaked lime, carbide slag, sodium carbonate, sodium bicarbonate and trona; in the step of obtaining the deeply purified flue gas, the absorbent is selected from one or more of quick lime, slaked lime, carbide slag, sodium carbonate, sodium bicarbonate and trona.
The application provides a flue gas purification device, which further comprises a first-stage absorbent injection device and a second-stage absorbent injection device, wherein the first-stage absorbent injection device is arranged on an SCR inlet flue, and the second-stage absorbent injection device is arranged between an SCR reactor and an air preheater; this application is through setting up absorbent injection device before SCR reactor, but SO that injected absorbent high-efficient desorption boiler combustion generated 3 The HCl and the HF can reduce the allowable operating temperature of the SCR, improve the adaptability of the device to different working conditions and prolong the service life of the catalyst; the absorbent sprayed by the absorbent spraying device is arranged behind the SCR reactor to remove newly generated SO 3 The air preheater is prevented from being blocked, and the heat exchange efficiency and the operation reliability of the air preheater are ensured. Furthermore, the atomization humidification device is arranged in an outlet flue of an air preheater of the flue gas purification device, and can be timely opened according to the temperature of flue gas and the concentration of pollutants, so that the removal efficiency is further improved.
Drawings
FIG. 1 is a schematic structural diagram of a flue gas purification device according to the present invention;
FIG. 2 is a bottom view of an absorbent suspension gas tray apparatus of the present invention;
FIG. 3 is a front view of an absorbent suspension aerosol generating assembly of the present invention;
FIG. 4 is a schematic view of a flue gas turbulence apparatus of the present invention;
fig. 5 is a schematic diagram of the position of the flue gas turbulence device in the flue.
Detailed Description
For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.
The application provides a flue gas purification device, it includes: the system comprises an SCR reactor inlet flue 2, a flue gas turbulence device 3, a first-stage absorbent injection device 4, an SCR reactor 5, an SCR reactor outlet flue 6, a second-stage absorbent injection device 7, an absorbent suspension gas support device 8, an air preheater 9, an air preheater outlet flue 10, an absorbent bin 11, an absorbent quantitative supply device 12, a water tank 13 and an atomization humidification device 14, wherein the boiler 1 is a flue gas generating source; as shown in fig. 1, an embodiment of the present invention discloses a flue gas purification apparatus, which includes:
the system comprises an SCR reactor inlet flue, an SCR reactor outlet flue, an air preheater and an air preheater outlet flue; the outlet end of the boiler is provided with the SCR reactor inlet flue, the outlet end of the SCR reactor inlet flue is provided with the SCR reactor, the outlet end of the SCR reactor is provided with the SCR reactor outlet flue, the outlet of the SCR reactor outlet flue is provided with the air preheater, and the outlet end of the air preheater is provided with the air preheater outlet flue; the flue gas purification device further comprises: the device comprises a first-stage absorbent spraying device, a second-stage absorbent spraying device, an absorbent bin and an absorbent quantitative supply device;
a first-stage absorbent injection device is arranged on the inlet flue of the SCR reactor;
a second-stage absorbent spraying device is arranged on the flue at the outlet of the SCR reactor;
the lower end of the absorbent bin is provided with an absorbent quantitative supply device;
the outlet end of the absorbent quantitative supply device is respectively connected with the inlet ends of the first-stage absorbent injection device and the second-stage absorbent injection device.
The first-stage absorbent spraying device and the second-stage absorbent spraying device are respectively arranged on the inlet flue and the outlet flue of the SCR reactor, SO that the absorbent is added in a segmented manner and is used for removing SO in flue gas 3 HCl and HF, thereby improving the working condition adaptability of the SCR denitration device and ensuring the denitration efficiency of the catalystThe efficiency and the service life of the air preheater are avoided, the scaling and blockage of the air preheater are avoided, the corrosion risk of a flue and equipment is reduced, and the SO caused by the corrosion is eliminated 3 Forming a colored smoke plume.
According to the invention, the inlet flue of the SCR reactor, the outlet flue of the SCR reactor, the air preheater and the outlet flue of the air preheater in the flue gas purification device are all conventional arrangements of technicians in the field, and the application is not particularly limited; specifically, the exit end of the boiler is provided with SCR reactor inlet flue, the exit end of SCR reactor inlet flue is provided with the SCR reactor, the exit end of SCR reactor is provided with SCR reactor outlet flue, the export of SCR reactor outlet flue is provided with air heater, air heater's exit end is provided with air heater outlet flue.
The flue gas purification device also comprises a first-stage absorbent injection device, a second-stage absorbent injection device, an absorbent bin and an absorbent quantitative supply device; the first-stage absorbent injection device and the second-stage absorbent injection device are respectively arranged in an inlet flue and an outlet flue of the SCR reactor, and the outlet of the absorbent quantitative supply device at the lower end of the absorbent bin is respectively connected with the inlets of the first-stage absorbent injection device and the second-stage absorbent injection device.
In industrial production, flue gas generated by boiler combustion enters an SCR reactor through an inlet flue of the SCR reactor, a first-stage absorbent injection device is arranged at the inlet flue of the SCR reactor, and preferably fluidized air or compressed air is used for conveying absorbent to the first-stage absorbent injection device SO that the injected absorbent reacts with the flue gas entering the inlet flue of the SCR reactor to complete the reaction of original SO in the flue gas 3 The method can efficiently remove the HCl, HF and other pollutants in the flue gas, and can primarily purify the HCl, HF and other pollutants. In order to fully mix the injected absorbent with the flue gas, the first-stage absorbent injection device is composed of a plurality of injection points. From the flow direction of flue gas, the upstream of first order absorbent injection apparatus is provided with flue gas turbulent flow device to further guarantee absorbent and the intensive mixing of flue gas. The flue gas turbulence device is a ring type rotaryThe vortex turbulence device consists of an inner ring, an outer ring and middle swirl blades; the included angle between the rotational flow blade and the horizontal plane is 20-60 degrees, and the included angle between the flue gas turbulent flow device and the flow direction of the flue gas is 60-90 degrees. The structure of the flue gas turbulence device is schematically shown in fig. 4 and 5. In the flue gas turbulence device, the absorbent is sprayed into a swirl zone at the rear end of a swirl blade and annular connection zone, the full mixing of the absorbent and the flue gas is enhanced through the swirl action of the flue gas, and meanwhile, the absorbent and the flue gas are fully mixed through annular swirl airflow in an outer annular zone, so that the full mixing of the flue gas and the absorbent is realized.
The flue gas after primary purification of the first-stage absorbent injection device in the inlet flue of the SCR reactor enters the SCR reactor to react with an SCR catalyst loaded in the SCR reactor, the flue gas after reaction enters the outlet flue of the SCR reactor, the second-stage absorbent injection device arranged on the outlet flue preferably conveys the absorbent into the second-stage absorbent injection device under the action of fluidized wind or compressed air, and the second-stage absorbent injection device is also provided with a plurality of injection points to ensure that the injected absorbent is fully mixed with the flue gas to fully mix SO in the flue gas 3 HCl and HF were purified again. In order to prevent the absorbent from settling and improve the utilization rate of the absorbent and the removal efficiency of a system, an absorbent suspension gas support device is arranged in a horizontal flue at the downstream of the second-stage absorbent injection device and is arranged in multiple sections; from the flowing direction of the flue gas, the included angle between the suspended gas supporting hole of the absorbent suspended gas supporting device and the flue is 70-110 degrees. Fluidized wind or compressed air is sprayed into the flue through the distribution header through the suspended gas supporting holes. The absorbent suspension gas-supporting device is specifically shown in fig. 2 and 3, wherein 15 in fig. 2 and 3 is a flue wall, 16 is a suspension gas-supporting air hole, and 17 is a distribution header.
And finally, the smoke after secondary purification flows out from an outlet flue of the air preheater after heat exchange of the air preheater to obtain the deeply purified smoke, and the smoke at the moment can enter smoke purification units at the rear end, such as a desulfurization unit, a dedusting unit and the like. In order to further improve the removal efficiency, the flue gas purification device further comprises an atomization humidification device, and an atomization humidification device is arranged on an outlet flue of the air preheater. To prevent absorptionAnd settling the agent, wherein an absorbent suspension gas supporting device is arranged on an outlet flue of the air preheater, and an included angle between a suspension gas supporting hole of the suspension gas supporting device and the flue is 70-110 degrees. The absorbent suspension gas supporting device only needs to be arranged on the outlet flue of the air preheater, and can be arranged at the upstream of the atomization and humidification device or at the downstream of the atomization and humidification device, and the application is not particularly limited. The temperature of the flue gas at the outlet of the SCR ranges from 300 ℃ to 400 ℃, and SO is generated at a higher temperature 3 Has larger reaction activation energy, SO, when reacting with the absorbent 3 The HCl, the HF and the absorbent are in gas-solid reaction, so that the removing efficiency is high. The temperature of the flue gas at the outlet of the air preheater is usually below 150 ℃, the reaction activation energy is low, the removal efficiency is low, and a liquid film and SO are formed on the surface of the absorbent through atomization and humidification 3 HCl and HF are soluble in the liquid film, SO 3 The reaction of HCl and HF with absorbent is changed from gas-solid reaction to liquid-solid reaction, so that the removing efficiency can be improved. The reaction and removal mechanisms are different under different temperature conditions, the atomization and humidification are mainly arranged at the outlet of the air preheater under the low temperature condition, the removal efficiency can be improved, and the atomization and humidification are not needed under the high temperature condition.
SO 3 The generation mainly comes from two aspects: a) Conversion of coal to SO during combustion in the boiler 3 The first-stage absorbent injection point is arranged in the flue gas inlet flue of the SCR and is mainly used for removing the SO in the flue gas before entering the SCR reactor 3 (ii) a b) The flue gas passes through the SCR reactor, and the SCR reactor is loaded with SCR catalyst, wherein V is in the SCR catalyst 2 O 5 The components can lead part of SO in the flue gas 2 Conversion to SO 3 A second-stage absorbent injection point is arranged in the flue at the outlet of the SCR for removing the residual SO in the first-stage reaction 3 And SO newly generated after passing through the SCR reactor 3 Guarantee SO 3 Overall removal efficiency of HCl and HF.
The second-stage absorbent spraying device is arranged in the flue at the outlet of the SCR reactor, and is not directly arranged behind the first-stage absorbent spraying device, so that the dosage of the sprayed absorbent is reduced before entering the SCR reactor, and only the absorbent is removed into the flue gas before entering the SCR reactorMost of the SO 3 And (4) finishing. The risk of abrasion, blockage and the like to the catalyst possibly caused by spraying the absorbent is reduced; in addition, the absorbent is mainly calcium-based or sodium-based absorbent, and a large amount of calcium-based or sodium-based components are attached to the surface of the catalyst, so that the catalyst is poisoned. The absorbent adding devices are respectively arranged in front of the SCR reactor and behind the SCR reactor in a segmented manner, so that the removal efficiency of the catalyst can be ensured, and the service life of the catalyst can be prolonged.
The application provides a flue gas purification device, not only effectively promoted the system to SO 3 HCl and HF eliminating efficiency to avoid NH 4 HSO 4 The method has the advantages of generating adverse effects such as dust deposition, blockage and the like on the SCR catalyst and an air preheater, reducing the dosage of the absorbent added in front of the SCR catalyst, and avoiding the poisoning and blockage of the catalyst caused by the addition of a large amount of calcium-based and sodium-based absorbents.
The invention also provides a method for purifying smoke by using the smoke purifying device, which comprises the following steps:
mixing flue gas generated by combustion in a boiler with an absorbent to obtain primarily purified flue gas;
the flue gas which is preliminarily purified enters an SCR reactor for reaction to obtain the flue gas after the reaction;
and mixing the reacted flue gas with the absorbent again, and discharging the flue gas after heat exchange to obtain the deeply purified flue gas.
In the above process, in the step of preliminarily purifying the flue gas, the absorbent is selected from one or more of quick lime, slaked lime, carbide slag, sodium carbonate, sodium bicarbonate and trona; the absorbent and SO in the flue gas 3 The molar ratio of (1-1.5): 1, too small a molar ratio, SO 3 The removal efficiency is limited, and the molar ratio is too large, which can cause adverse effects on the catalyst. In the step of obtaining the deeply purified flue gas, the absorbent is selected from one or more of quick lime, slaked lime, carbide slag, sodium carbonate, sodium bicarbonate and trona; the SO in the absorbent and the flue gas 3 The molar ratio of (1-3): 1, excessive molar ratio can cause waste of the absorbent, and increase the abrasion and accumulation of the air preheater and the flueRisk of ash. The catalyst in the SCR reactor is a catalyst well known to those skilled in the art, and is not particularly limited herein.
For further understanding of the present invention, the following detailed description will be made of the flue gas purification device and method provided by the present invention with reference to the following examples, and the scope of the present invention is not limited by the following examples.
Example 1
A flue gas cleaning device, comprising: an SCR inlet flue 2; a flue gas turbulence device 3; a first stage absorbent injection device 4; an SCR reactor 5; an SCR outlet flue 6; a second stage absorbent injection device 7; an absorbent suspension gas-bearing device 8; an air preheater 9; an air preheater exit flue 10; an absorbent bin 11; an absorbent dosing device 12; a water tank 13; an atomizing humidifier 14;
an SCR inlet flue 2 is arranged at the outlet end of a boiler 1, an SCR reactor 5 is arranged at the outlet end of the SCR inlet flue 2, a flue gas turbulence device 3 and a first-stage absorbent injection device 4 are sequentially arranged in the SCR inlet flue 2, an air preheater 9 is arranged at the outlet end of the SCR reactor 5, a second-stage absorbent injection device 7 and an absorbent suspended gas support device 8 are sequentially arranged between the SCR reactor 5 and the air preheater 9, an air preheater outlet flue 10 is arranged at the outlet end of the air preheater 9, the absorbent suspended gas support device 8 and an atomization humidification device 14 are sequentially arranged on the air preheater outlet flue 10, the first-stage absorbent injection device 4 and the second-stage absorbent injection device 7 are both connected with an absorption and quantification device 12 arranged at the lower end of an absorbent bin 11, and the atomization humidification device 14 is connected with an outlet of a water tank 13. The flue gas cleaning device of the present embodiment is shown in fig. 1.
Example 2
The smoke quantity of a certain coal-fired boiler is 830000m 3 And h, the absorbent spraying device and the atomization humidifying device are not started. Raw flue gas SO of outlet flue of air preheater 2 The concentration is 5700mg/Nm 3 ，SO 3 The concentration is 105.4mg/Nm 3 HCl concentration 18.8mg/Nm 3 HF concentration of 2.2mg/Nm 3 。
Cigarette applied to example 1The flue gas that gas purifier, burning produced in the boiler loops through SCR entry flue, SCR reactor, SCR export flue, air heater and air heater export flue. Opening the first-stage absorbent injection device and the second-stage absorbent injection device, and injecting sodium carbonate into the flue; SO in flue gas after purification of outlet flue of air preheater 3 The concentration is 7.6mg/Nm 3 The removal efficiency is 92.8%; HCl concentration 3.3mg/Nm 3 The removal efficiency is 82.4%; HF concentration of 0.6mg/Nm 3 The removal efficiency was 72.7%.
Example 3
Applied to the flue gas purification device of the embodiment 1, the flue gas volume of a certain coal-fired boiler is 520000m 3 And h, the absorbent spraying device and the atomization humidifying device are not started. Raw flue gas SO of outlet flue of air preheater 2 The concentration is 4200mg/Nm 3 ，SO 3 The concentration was 61.3mg/Nm 3 HCl concentration 9.5mg/Nm 3 HF concentration of 3.7mg/Nm 3 。
Flue gas generated by combustion in the boiler sequentially passes through the SCR inlet flue, the SCR reactor, the SCR outlet flue air preheater and the air preheater outlet flue. And the first-stage absorbent injection device and the second-stage absorbent injection device are started, slaked lime is injected into the flue, and meanwhile, the humidifying device at the outlet flue of the air preheater is started to atomize the process water and then inject the atomized process water into the flue. SO in the humidified and purified flue gas 3 The concentration is 3.8mg/Nm 3 The removal efficiency is 93.8%; HCl concentration 0.8mg/Nm 3 The removal efficiency is 91.6%; HF concentration of 0.5mg/Nm 3 The removal efficiency is 86.5 percent
Example 4
Same apparatus as in example 2, the amount of smoke was 480000Nm 3 H, raw flue gas SO of outlet flue of air preheater 2 The concentration is 3900mg/Nm 3 ，SO 3 The concentration was 58.6mg/Nm 3 HCl concentration of 8.9mg/Nm 3 HF concentration of 3.6mg/Nm 3 。
Flue gas generated by combustion in the boiler sequentially passes through the SCR inlet flue, the SCR reactor, the SCR outlet flue, the air preheater and the air preheater outlet flue. First stage suctionThe recycling agent spraying device and the secondary absorbent spraying device are opened and both spray sodium carbonate into the flue; and simultaneously, starting a flue humidifying device at the outlet of the air preheater to atomize the process water and then spray the atomized process water into the flue. SO in humidified and purified flue gas 3 The concentration is 2.5mg/Nm 3 The removal efficiency is 95.7%; HCl concentration 0.6mg/Nm 3 The removal efficiency is 93.3%; HF concentration of 0.4mg/Nm 3 The removal efficiency was 88.9%.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A flue gas cleaning device comprising: the system comprises an SCR reactor inlet flue, an SCR reactor outlet flue, an air preheater and an air preheater outlet flue; the outlet end of the boiler is provided with the SCR reactor inlet flue, the outlet end of the SCR reactor inlet flue is provided with the SCR reactor, the outlet end of the SCR reactor is provided with the SCR reactor outlet flue, the outlet of the SCR reactor outlet flue is provided with the air preheater, and the outlet end of the air preheater is provided with the air preheater outlet flue; it is characterized in that the flue gas purification device further comprises: the device comprises a first-stage absorbent spraying device, a second-stage absorbent spraying device, an absorbent bin and an absorbent quantitative supply device;
a first-stage absorbent spraying device is arranged on the inlet flue of the SCR reactor;
a second-stage absorbent injection device is arranged on the outlet flue of the SCR reactor;
the lower end of the absorbent bin is provided with an absorbent quantitative supply device;
the outlet end of the absorbent quantitative supply device is respectively connected with the inlet ends of the first-stage absorbent injection device and the second-stage absorbent injection device;
the flue gas purification device also comprises an atomization humidification device, and an atomization humidification device is arranged on an outlet flue of the air preheater;
the SCR outlet flue is provided with an absorbent suspension gas supporting device, the included angle between the suspension gas supporting air holes of the suspension gas supporting device and the flue is 70-110 degrees, the absorbent suspension gas supporting device is arranged in the horizontal flue at the downstream of the second-stage absorbent injection device, the outlet flue of the air preheater is provided with the absorbent suspension gas supporting device, and the included angle between the suspension gas supporting air holes of the suspension gas supporting device and the flue is 70-110 degrees.
2. The flue gas purification device according to claim 1, further comprising a water tank, wherein a water pump is arranged at an outlet end of the water tank, and the water pump is connected with an inlet end of the atomization spraying device.
3. The flue gas purification device according to claim 1 or 2, wherein the first stage absorbent injection means and the second stage absorbent injection means are each provided with a plurality of injection points.
4. The flue gas purification device according to claim 1 or 2, wherein a flue gas turbulence device is further arranged on the inlet flue of the SCR reactor, and the flue gas turbulence device is arranged upstream of the first-stage absorbent injection device.
5. The flue gas purification device according to claim 4, wherein the flue gas turbulence device is a ring-type swirling flow turbulence device which is composed of an inner ring, an outer ring and middle swirling vanes; the included angle between the swirl vanes and the horizontal plane is 20-60 degrees, and the included angle between the flue gas turbulent flow device and the flow direction of the flue gas is 60-90 degrees.
6. A method of flue gas purification comprising the steps of:
mixing flue gas generated by combustion in a boiler with an absorbent to obtain primarily purified flue gas;
the flue gas purified primarily enters an SCR reactor for reaction to obtain the flue gas after reaction;
and mixing the reacted flue gas with the absorbent again, and discharging the flue gas after heat exchange to obtain the deeply purified flue gas.
7. The flue gas purification method according to claim 6, further comprising, after the heat exchange and before the discharging:
atomizing and humidifying the flue gas after heat exchange.
8. The flue gas purification method according to claim 6, wherein in the step of obtaining the preliminarily purified flue gas, the absorbent and SO in the flue gas are mixed 3 In a molar ratio of (1-1.5): 1; in the step of obtaining the deeply purified flue gas, the SO in the absorbent and the flue gas 3 The molar ratio of (1-3): 1.
9. the method for purifying flue gas according to claim 6, wherein in the step of obtaining the preliminarily purified flue gas, the absorbent is conveyed by fluidized wind or compressed air as a carrier; in the step of obtaining the deeply purified flue gas, the absorbent is conveyed by taking fluidized wind or compressed air as a carrier.
10. The flue gas purification method according to claim 6, wherein in the step of obtaining the preliminarily purified flue gas, the absorbent is selected from one or more of quick lime, slaked lime, carbide slag, sodium carbonate, sodium bicarbonate and trona; in the step of obtaining the deeply purified flue gas, the absorbent is selected from one or more of quick lime, slaked lime, carbide slag, sodium carbonate, sodium bicarbonate and trona.
CN201710058501.9A 2017-01-23 2017-01-23 Flue gas purification device and method Active CN106582286B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710058501.9A CN106582286B (en) 2017-01-23 2017-01-23 Flue gas purification device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710058501.9A CN106582286B (en) 2017-01-23 2017-01-23 Flue gas purification device and method

Publications (2)

Publication Number Publication Date
CN106582286A CN106582286A (en) 2017-04-26
CN106582286B true CN106582286B (en) 2022-12-13

Family

ID=58586767

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710058501.9A Active CN106582286B (en) 2017-01-23 2017-01-23 Flue gas purification device and method

Country Status (1)

Country Link
CN (1) CN106582286B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108654567B (en) * 2018-05-14 2020-02-07 东南大学 Medium-high temperature dechlorinating agent for removing HCl gas in flue gas and preparation method thereof
CN109622204A (en) * 2018-11-12 2019-04-16 南京环境再生能源有限公司 A kind of garbage burning factory fume treatment sodium bicarbonate flouring technology
CN109486534B (en) * 2018-12-20 2021-06-08 中国平煤神马能源化工集团有限责任公司 Coal gas dust removal and desulfurization method
CN111503637A (en) * 2019-07-23 2020-08-07 河北燕岛环保科技股份有限公司 Process and device for pyrolyzing household garbage by low-nitrogen combustion
CN110523276A (en) * 2019-09-30 2019-12-03 大唐郓城发电有限公司 A kind of flue gas processing device and its method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103143254A (en) * 2013-03-22 2013-06-12 福建龙净脱硫脱硝工程有限公司 Compound airflow generator, circulating fluidized bed tower-front two-phase premixing device and method
CN103697488A (en) * 2013-12-27 2014-04-02 四川川润动力设备有限公司 System for removing PM2.5 (particulate matter 2.5) and sulfur together, and CFB system and method
CN105879620A (en) * 2016-05-12 2016-08-24 大唐环境产业集团股份有限公司 Two-stage flue gas sulphur trioxide removing device and method for flue gas purification
CN206474018U (en) * 2017-01-23 2017-09-08 福建龙净脱硫脱硝工程有限公司 A kind of smoke eliminator

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10202048A (en) * 1997-01-21 1998-08-04 Ishikawajima Harima Heavy Ind Co Ltd Treatment of stack gas from boiler plant and device therefor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103143254A (en) * 2013-03-22 2013-06-12 福建龙净脱硫脱硝工程有限公司 Compound airflow generator, circulating fluidized bed tower-front two-phase premixing device and method
CN103697488A (en) * 2013-12-27 2014-04-02 四川川润动力设备有限公司 System for removing PM2.5 (particulate matter 2.5) and sulfur together, and CFB system and method
CN105879620A (en) * 2016-05-12 2016-08-24 大唐环境产业集团股份有限公司 Two-stage flue gas sulphur trioxide removing device and method for flue gas purification
CN206474018U (en) * 2017-01-23 2017-09-08 福建龙净脱硫脱硝工程有限公司 A kind of smoke eliminator

Also Published As

Publication number Publication date
CN106582286A (en) 2017-04-26

Similar Documents

Publication Publication Date Title
CN106582286B (en) Flue gas purification device and method
CN101314105A (en) Control technique and apparatus for flue gas NOx of cement kiln
CN108636092B (en) Flue gas desulfurization and denitrification system and method
CN110252051B (en) Method for dedusting, desulfurizing and denitrating boiler flue gas and removing dioxin
CN109603539A (en) A kind of industrial smoke high temperature desulfurizing denitration dust removal system and its processing method
CN107029546A (en) SO based on alkaline absorbent fine particle3Removing system and its removal methods
CN111744362A (en) Ceramic industry comprehensive flue gas cooperative treatment system
CN109529616A (en) Cement kiln equipment for denitrifying flue gas
CN107008120A (en) Utilize the SO of urea pyrolysis waste heat3Removing system and its removal methods
CN113144862A (en) Biomass incineration power generation flue gas ultralow emission system and emission method thereof
CN112138542A (en) High-temperature flue gas dedusting, denitration and desulfurization system and method
CN209714765U (en) A kind of industrial smoke high temperature desulfurizing denitration dust removal system
CN114849471A (en) HTr-3SO combined denitration system applied to treatment of glass fiber kiln waste gas
CN202387362U (en) Semi-dry low temperature flue gas denitrification system
CN106178877A (en) A kind of coke oven flue waste gas purification waste heat recovery apparatus and technique
CN209302510U (en) Flue gas purification system
CN204933244U (en) NOx removal device in coal-burning power plant's coal-powder boiler flue gas
CN209934440U (en) Civil heating boiler desulfurization and denitrification system
CN208542022U (en) Incineration flue gas non-catalytic reduction denitrating system based on high concentration reducing agent
JPH0693971B2 (en) Simultaneous desulfurization denitration method in furnace
CN206474018U (en) A kind of smoke eliminator
CN212236738U (en) Gas purification system
CN206867999U (en) SO3 removing systems based on alkaline absorbent fine particle
CN112495151A (en) Method for eliminating blue smoke plume of chimney of coal-fired boiler
CN207493486U (en) A kind of desulfurization of coke oven flue gas and de-dusting de-nitration integrated

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant