CN113856429B - Magnesium desulfurization device and method based on resource utilization - Google Patents
Magnesium desulfurization device and method based on resource utilization Download PDFInfo
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- CN113856429B CN113856429B CN202111160127.6A CN202111160127A CN113856429B CN 113856429 B CN113856429 B CN 113856429B CN 202111160127 A CN202111160127 A CN 202111160127A CN 113856429 B CN113856429 B CN 113856429B
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- 238000006477 desulfuration reaction Methods 0.000 title claims abstract description 128
- 230000023556 desulfurization Effects 0.000 title claims abstract description 128
- 238000000034 method Methods 0.000 title claims abstract description 64
- 239000011777 magnesium Substances 0.000 title claims abstract description 53
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 229910052749 magnesium Inorganic materials 0.000 title claims abstract description 29
- 239000002002 slurry Substances 0.000 claims abstract description 192
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims abstract description 188
- 239000003546 flue gas Substances 0.000 claims abstract description 188
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 116
- 230000003647 oxidation Effects 0.000 claims abstract description 106
- 230000029087 digestion Effects 0.000 claims abstract description 72
- 239000007921 spray Substances 0.000 claims abstract description 71
- 239000007788 liquid Substances 0.000 claims abstract description 69
- 239000007789 gas Substances 0.000 claims abstract description 50
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims abstract description 44
- 238000010521 absorption reaction Methods 0.000 claims abstract description 42
- 238000001704 evaporation Methods 0.000 claims abstract description 42
- 230000008020 evaporation Effects 0.000 claims abstract description 42
- 239000007787 solid Substances 0.000 claims abstract description 37
- 239000002562 thickening agent Substances 0.000 claims abstract description 28
- 239000000395 magnesium oxide Substances 0.000 claims abstract description 25
- 230000008569 process Effects 0.000 claims abstract description 18
- 238000001914 filtration Methods 0.000 claims abstract description 17
- 238000001035 drying Methods 0.000 claims abstract description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 110
- 239000000706 filtrate Substances 0.000 claims description 51
- 239000000428 dust Substances 0.000 claims description 38
- 239000013078 crystal Substances 0.000 claims description 37
- 239000000843 powder Substances 0.000 claims description 35
- 239000012452 mother liquor Substances 0.000 claims description 33
- 239000000047 product Substances 0.000 claims description 33
- 230000008878 coupling Effects 0.000 claims description 32
- 238000010168 coupling process Methods 0.000 claims description 32
- 238000005859 coupling reaction Methods 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 21
- 238000000926 separation method Methods 0.000 claims description 19
- 239000012065 filter cake Substances 0.000 claims description 18
- 238000002425 crystallisation Methods 0.000 claims description 17
- 230000008025 crystallization Effects 0.000 claims description 17
- 238000001816 cooling Methods 0.000 claims description 15
- 230000005484 gravity Effects 0.000 claims description 13
- 230000001590 oxidative effect Effects 0.000 claims description 13
- 239000002912 waste gas Substances 0.000 claims description 12
- 238000006243 chemical reaction Methods 0.000 claims description 11
- 239000003795 chemical substances by application Substances 0.000 claims description 11
- 229910000831 Steel Inorganic materials 0.000 claims description 10
- 239000003054 catalyst Substances 0.000 claims description 10
- 239000010959 steel Substances 0.000 claims description 10
- 239000008394 flocculating agent Substances 0.000 claims description 7
- 230000014759 maintenance of location Effects 0.000 claims description 7
- 238000004140 cleaning Methods 0.000 claims description 6
- 238000007865 diluting Methods 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 5
- 238000005507 spraying Methods 0.000 claims description 4
- 230000003009 desulfurizing effect Effects 0.000 claims description 2
- 238000009413 insulation Methods 0.000 claims description 2
- 230000000149 penetrating effect Effects 0.000 claims description 2
- 230000000630 rising effect Effects 0.000 claims description 2
- 238000005406 washing Methods 0.000 claims 1
- 238000002156 mixing Methods 0.000 abstract description 21
- 238000010438 heat treatment Methods 0.000 abstract description 10
- 230000000694 effects Effects 0.000 abstract description 7
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 abstract description 6
- 238000005516 engineering process Methods 0.000 abstract description 4
- 238000003756 stirring Methods 0.000 abstract description 4
- 125000004122 cyclic group Chemical group 0.000 abstract description 2
- JESHZQPNPCJVNG-UHFFFAOYSA-L magnesium;sulfite Chemical compound [Mg+2].[O-]S([O-])=O JESHZQPNPCJVNG-UHFFFAOYSA-L 0.000 abstract description 2
- CSNNHWWHGAXBCP-UHFFFAOYSA-L Magnesium sulfate Chemical compound [Mg+2].[O-][S+2]([O-])([O-])[O-] CSNNHWWHGAXBCP-UHFFFAOYSA-L 0.000 abstract 2
- 230000007613 environmental effect Effects 0.000 abstract 1
- 229910052943 magnesium sulfate Inorganic materials 0.000 abstract 1
- 235000019341 magnesium sulphate Nutrition 0.000 abstract 1
- 238000005728 strengthening Methods 0.000 abstract 1
- 239000012530 fluid Substances 0.000 description 48
- 208000028659 discharge Diseases 0.000 description 21
- 238000009826 distribution Methods 0.000 description 16
- 238000005381 potential energy Methods 0.000 description 10
- 238000009792 diffusion process Methods 0.000 description 9
- 239000002245 particle Substances 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 238000005265 energy consumption Methods 0.000 description 4
- 239000004615 ingredient Substances 0.000 description 4
- 239000000779 smoke Substances 0.000 description 4
- 229910019440 Mg(OH) Inorganic materials 0.000 description 3
- 230000009471 action Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000003595 mist Substances 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 239000012629 purifying agent Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- SMDQFHZIWNYSMR-UHFFFAOYSA-N sulfanylidenemagnesium Chemical compound S=[Mg] SMDQFHZIWNYSMR-UHFFFAOYSA-N 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000010907 mechanical stirring Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
- B01D53/504—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific device
-
- 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
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
- B01D53/502—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific solution or suspension
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F5/00—Compounds of magnesium
- C01F5/40—Magnesium sulfates
-
- 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
- B01D2251/402—Alkaline earth metal or magnesium compounds of magnesium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/60—Inorganic bases or salts
- B01D2251/604—Hydroxides
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Environmental & Geological Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Treating Waste Gases (AREA)
Abstract
The invention provides a magnesium desulfurization device and a magnesium desulfurization method based on resource utilization, wherein the desulfurization device comprises a digestion tank, a flash tank, a jet spray tank, a flue gas absorption tower, a bulge filter, an oxidation tank I, an oxidation tank II, a rotary drum centrifuge I, a flash evaporator, an OSLO crystallizer, a thickener, a rotary drum centrifuge II, a fluidized bed dryer and a product bin which are connected in sequence; the desulfurization method adopts a jet spray strengthening technology, magnesium oxide digestion and magnesium sulfite oxidation adopt a novel jet stirrer, high-speed jet mixing and stirring are adopted, heat transfer and mass transfer are strengthened, and gas, liquid and solid mixing and stirring effects are improved; recovering heat generated in digestion, oxidation and drying processes as main heating source, filtering and concentrating MgSO 3 Slurry was concentrated over evaporation MgSO 4 Solution, comprehensive energy saving is achieved by 50%; the invention has simple process flow, continuous operation, high automation degree, cyclic utilization of resources and environmental protection, and realizes reasonable utilization of magnesium sulfate resources.
Description
Technical Field
The invention belongs to the field of chemical equipment and desulfurization processes, and particularly relates to a magnesium desulfurization device and method based on resource utilization.
Background
Wet magnesium desulfurization refers to the preparation of Mg (OH) from MgO 2 Slurry, and SO in flue gas of thermal power plant is removed by utilizing absorption tower 2 Is a desulfurization method. The magnesium desulfurization method has the advantages of high desulfurization efficiency, safe and reliable operation, good operability, but higher cost. The magnesium desulfurization by-product is necessary to be recovered, the energy is reasonably circulated, and the physical utilization of resources is realized.
Magnesium desulfurization byproductThe recycling of the materials is to recycle the byproducts of the desulfurization, namely MgSO 3 Oxidative preparation of MgSO 4 ·7H 2 O. Digestion of MgO, mgSO 3 The oxidation reaction generally adopts a kettle type reactor and mechanical stirring; the preparation method has the defects that the kettle type reactor transfers heat through a jacket or an inner coil, the heat exchange efficiency is low, the heat loss in the heat exchange process is more, the operation period is short, the continuous production can not be realized, and the system can not stably run for a long period. In this method, digestion, oxidation and MgSO are carried out 4 The energy consumption in the solution concentration stage is large and accounts for more than 50% of the energy consumption in the whole process, and the cost is increased due to the increase of the energy consumption, so that the method is not beneficial to industrial production.
The field is urgent to find a method for realizing reasonable utilization of resources, which can overcome the technical problems.
Disclosure of Invention
Aiming at the engineering problems and market demands, in order to overcome the problems in the prior art, the invention provides a magnesium desulfurization device and a magnesium desulfurization method based on resource utilization, and the desulfurization device and the desulfurization process are simple in flow, continuous in operation, high in automation degree, cyclic in resource utilization, environment-friendly and used for realizing long-period stable operation of magnesium desulfurization; simultaneously recovering MgSO 3 Oxidative preparation of MgSO 4 ·7H 2 O, the heat of the fluidized bed dryer is recovered, the heat of digestion reaction and the heat of the flash evaporator are recovered by utilizing the MVR technology, so that the energy consumption is greatly reduced; the digestion reaction, the oxidation reaction and the desulfurization reaction all adopt jet technology.
The technical scheme adopted for solving the technical problems is as follows: a magnesium desulfurization device based on resource utilization comprises a digestion tank, a flash tank, a jet spray tank, a flue gas absorption tower, a bulge filter, an oxidation tank I, an oxidation tank II, a rotary drum centrifuge I, a flash evaporator, an OSLO crystallizer, a thickener, a rotary drum centrifuge II, a fluidized bed dryer and a product bin which are connected in sequence; the jet spray tank is used for obtaining Mg (OH) through digestion reaction and flash evaporation 2 Carrying out jet spray enhanced desulfurization on the slurry; the flue gas absorption tower is used for circulating the desulfurization slurry and the desulfurization flue gas obtained in the jet spray tankThe loop countercurrent contact continues to desulphurize; the drum filter is used for concentrating MgSO 3 Slurry; concentrated MgSO 3 The MgSO is generated by the oxidation reaction of the first oxidation tank and the second oxidation tank 4 Slurry, mgSO 4 Separating the slurry by a rotary drum centrifuge I, enabling the separated filtrate to enter a flash evaporator for flash evaporation concentration, enabling the OSLO crystallizer to be used for cooling and crystallizing the flash evaporation concentrated slurry, enabling the obtained crystal slurry to enter a thickener for concentration, enabling the concentrated crystal slurry to enter a rotary drum centrifuge II for centrifugal separation, enabling the fluidized bed dryer to be used for drying the centrifugally separated crystal filter cake, and enabling the dried solid powder to enter a product bin;
The desulfurization device also comprises a first vapor compressor and a second vapor compressor; the first vapor compressor is connected with a flash evaporation gas outlet pipeline of the flash evaporation tank, and is used for boosting and heating low-pressure vapor obtained by flash evaporation of the flash evaporation tank into secondary water vapor which is used as a main heat source of the digestion tank and enters the digestion tank; the second steam compressor is connected with a steam outlet pipeline of the flash evaporator, and the second steam compressor boosts and heats the steam flashed by the flash evaporator into secondary steam serving as a main heat source of the fluidized bed dryer;
the desulfurization apparatus further includes: the cyclone separator and the bag filter are used for separating solid powder from hot air discharged from the fluidized bed dryer, the separated solid powder enters a product bin, and the separated hot air is used as an auxiliary heat source to be conveyed to the first oxidation tank and the second oxidation tank.
Further, the desulfurization apparatus further includes: the fluidized bed dryer is characterized by comprising a condensate water tank, wherein the condensate water tank is used for collecting steam condensate water generated by a heater of a flash evaporator, an air heater of the fluidized bed dryer and the built-in calandria heater, and the condensate water tank is used for conveying the collected condensate water to a digestion tank through a condensate water pump to serve as ingredient water, wherein the heat is provided by hot air generated by the built-in calandria heater and the air heater, and steam is used as a heat source by the built-in calandria heater and the air heater.
Further, the desulfurization device also comprises a flue gas heat exchanger, a flue gas dust remover and a chimney; the flue gas heat exchanger is used for exchanging heat between the flue gas of the power plant and the desulfurization flue gas discharged by the flue gas absorption tower, the desulfurization flue gas heated after heat exchange enters a chimney and is discharged, the flue gas of the power plant after cooling enters a flue gas dust remover, and the obtained dedusting flue gas enters a jet spray tank for desulfurization;
wherein the temperature of a flue gas inlet of a power plant in the flue gas heat exchanger is 125-130 ℃, the pressure is 0.1MPa, and SO is achieved 2 Concentration of 2500mg/Nm 3 ～2750mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The inlet temperature of the desulfurization flue gas is 50-55 ℃, the pressure is 0.1MPa, and the SO is generated 2 Concentration of 25mg/Nm 3 ～27.5mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The temperature of the flue gas outlet of the power plant is 85-90 ℃, and the temperature of the flue gas outlet of the desulfurization is 80-85 ℃;
the temperature of the desulfurized flue gas entering a chimney is 80-85 ℃;
in the flue gas dust remover, the temperature of a flue gas inlet of a power plant is 85-90 ℃, and the temperature of a dust removing flue gas outlet is 50-55 ℃.
Further, the flue gas absorption tower is provided with two sections of tower plates, a slurry spraying layer is arranged above each section of tower plate, an annular baffle is arranged on the tower wall below each section of tower plate, and the annular baffle and the tower wall are arranged at 45 degrees; two layers of demisters are arranged above the two sections of tower plates, and demister cleaning spray heads are arranged above each layer of demisters; a filtering liquid spray head is arranged between the two layers of demisters and the two sections of tower plates; the flue gas absorption tower is provided with a circulating slurry pipeline which is used for sucking desulfurization slurry in the flue gas absorption tower and conveying the desulfurization slurry to a slurry spraying layer and a bulge filter; and the filtering liquid spray head is connected with a filtering liquid outlet pipeline of the bulge filter.
Further, each section of tower plate comprises nine layers of herringbone tower pieces and nine layers of separating nets, a plurality of groups of herringbone tower pieces in each layer are respectively and uniformly paved on the corresponding separating nets in the flue gas absorption tower, and the herringbone tower pieces in odd and even layers are uniformly distributed in a staggered way; wherein the herringbone tower member is composed of angle steel; the two angle steel edges are connected upward and end-to-end, and welded into a right-angle-shaped member, and the three right-angle-shaped members and the apex angle upward are enclosed into a regular triangle and welded into a group of herringbone tower pieces; the separation net is composed of a supporting beam and a white steel bar penetrating through the supporting beam.
Further, the water vapor mainly provides auxiliary heat sources for the digestion tank, the oxidation tank I, the oxidation tank II and the fluidized bed dryer, and provides heat sources for the heater of the flash evaporator; the main heat sources of the first oxidation tank and the second oxidation tank are provided by hot air exhausted by a fluidized bed dryer, the main heat sources of the digestion tank are provided by secondary steam which is generated by a flash tank and is compressed by mechanical steam, namely, boosted and heated by a compressor, and the main heat sources of the fluidized bed dryer are provided by the secondary steam which is generated by the flash evaporator and is compressed by mechanical steam, namely, boosted and heated by the compressor; the digestion tank uses condensed water as main water for ingredients and uses process water as auxiliary water; the water vapor is 0.4MPa of common engineering, the temperature of 230 ℃ of the water vapor is 220 ℃ of the secondary water vapor, and the pressure of the superheated water vapor is 0.15 MPa.
The desulfurization method of the magnesium desulfurization device based on the resource utilization concretely comprises the following steps:
(1) MgO and water enter a digestion tank, and secondary steam is sucked by a jet stirrer and directly heated to perform digestion reaction to generate Mg (OH) 2 Slurry;
(2) Mg (OH) in digestion tank 2 The slurry enters a flash tank 2, and the low-pressure steam is flashed out and is subjected to mechanical steam recompression (MVR) through a steam compressor, namely, secondary steam with pressure boosting and temperature rising of the compressor provides a main heat source for a digestion tank;
(3) Mg (OH) after flash evaporation in flash tank 2 Diluting the slurry with process water, entering a jet spray tank, absorbing dust-removing flue gas through a coupling distributor, and performing jet spray enhanced desulfurization in the jet spray tank;
(4) The desulfurization slurry and the desulfurization flue gas of the jet spray tank enter a flue gas absorption tower, the desulfurization slurry forms circulating slurry in the tower, and the desulfurization flue gas is in countercurrent contact with the circulating slurry in the flue gas absorption tower to continuously desulfurize; part of the circulating slurry enters a bulge filter, the filtering liquid in the filter bag of the bulge filter enters a flue gas absorption tower to wash the desulfurization flue gas, and MgSO is concentrated outside the filter bag of the bulge filter 3 Slurry;
(5) Concentrated MgSO in a drum filter 3 The slurry enters into the first oxidation tank and at the same timeAdding catalyst, hot air, fresh air and water vapor, mgSO 3 Oxidation reaction is carried out to generate MgSO 4 ；
(6) The oxidized slurry in the first oxidizing tank enters the second oxidizing tank by gravity, and simultaneously, impurity removing agent, flocculating agent, decoloring agent, hot air, fresh air and water vapor are added, mgSO 3 Oxidation reaction is carried out to generate MgSO 4 ；
(7) The slurry oxidized in the second oxidation tank enters the first rotary drum centrifuge for centrifugal separation, and the filtrate obtained by centrifugal separation enters a flash evaporator for flash evaporation and concentration through one part of the filtrate tank, and enters an OSLO crystallizer for cooling and crystallization through the other part of the filtrate tank;
(8) The filtrate centrifugally separated by the rotary drum centrifuge II enters a flash evaporator through a filtrate tank to be subjected to flash evaporation concentration, and the low-pressure steam obtained by flash evaporation is compressed into secondary steam by a steam compressor to be used as a main heat source of the fluidized bed dryer;
(9) The filtrate and flash liquid enter an OSLO crystallizer for cooling crystallization, the crystal slurry enters a thickener through a crystal slurry outlet pipeline by gravity, and the crystal slurry concentrated by the thickener enters a rotary drum centrifuge II;
(10) The crystal slurry concentrated by the thickener enters a rotary drum centrifuge II for centrifugal separation, and the separated crystal filter cake enters a fluidized bed dryer through a screw feeder;
(11) The crystallized filter cake centrifugally separated by the rotary drum centrifuge II enters a fluidized bed dryer for drying through a screw feeder; the hot air and the solid powder discharged from the fluidized bed dryer are separated into the solid powder and the hot air through a cyclone separator and a bag filter; the separated hot air enters a first oxidation tank and a second oxidation tank, the separated solid powder and the solid powder dried by the fluidized bed dryer enter a product bin.
Further, mgO in the step (1) is 85MgO obtained by classifying light burned magnesia, wherein the mass content of MgO is not less than 85%, and the grain size is 95% less than 0.075mm.
Further, in the step (1), the digestion temperature in the digestion tank is 85-90 ℃, the pressure is 0.1MPa, the initial mass concentration of MgO is 10%, the retention time of the materials in the digestion tank is 2.5-3 h, and the secondary steam is sucked into the digestion tank through a jet mixer to directly heat the digestion slurry.
Further, in the step (2), the flash temperature in the flash tank is 80 ℃, the operation is performed in an adiabatic mode, and the flash steam enters a steam compressor; mg (OH) after flash evaporation 2 Diluting the slurry with process water to Mg (OH) 2 The mass concentration is 3%, and the Mg (OH) 2 The slurry pump enters the jet spray tank.
Further, in the step (3), the temperature in the jet spray tank is 50-55 ℃, the pressure is 0.45MPa, the retention time of the materials is 0.125-0.25 h, and the pH value is controlled to be 6.5-6.75; the temperature of the dust-removing flue gas is 50-55 ℃ and SO 2 Concentration of 2500mg/Nm 3 ～2750mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The dust-removing flue gas from the flue gas dust remover is sucked by the coupling distributor of the jet spray tank, and the reinforced desulfurization is carried out in the jet spray tank.
Further, in the step (4), the temperature in the flue gas absorption tower is 50-55 ℃, the pressure is 0.10MPa, the residence time of the desulfurized flue gas is 10-12 s, the gas speed is 3m/s, the pH value is controlled to be 5.8-6.5, and the liquid-gas ratio is 6L/Nm 3 ～7L/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the Desulfurizing the flue gas escaping from the jet spray tank in the flue gas absorption tower; in the step (4), the filtering liquid in the filter bag of the bulge filter enters a flue gas absorption tower to wash the desulfurization flue gas and wash solid particles on a tower plate, the MgSO3 slurry outside the filter bag is concentrated from 2% to 11% by mass, and the slurry enters the first oxidation tank through a pump.
Further, in the step (5), the catalyst is added into a first oxidation tank, hot air, fresh air and water vapor are sucked through a jet stirrer, the temperature in the first oxidation tank is 50-55 ℃, the pressure is 0.20MPa, and the material residence time is 3.5-4.0 h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidized serosity enters the second oxidizing tank, and the waste gas (which can take away part of water vapor) enters the waste gas treatment system through the waste gas discharge pipeline.
Further, in the step (6), part of the filter residue separated by the first centrifugal separation of the bowl centrifuge is mixed with the impurity removing agent, the flocculating agent and the decoloring agentThe mixture is added into a second oxidation tank, hot air, fresh air and water vapor are sucked through a jet stirrer, the temperature in the second oxidation tank is 50-55 ℃, the pressure is 0.15MPa, and the material residence time is 3.5-4.0 h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidized slurry enters a rotary drum centrifuge I, and the waste gas (which can take away part of water vapor) enters a waste gas treatment system through a waste gas discharge pipeline.
Further, in the step (7), the slurry oxidized in the oxidation tank II is discharged from the oxidation slurry discharge pump and enters the rotary drum centrifuge I for centrifugal separation, and a part of the separated filter residues (50 wt% is used for recovering the catalyst and unreacted MgSO) 3 ) Continuously oxidizing in a second oxidation tank, and allowing the other part of filter residues to enter a filter residue treatment system; the filtrate separated by the rotary drum centrifuge enters a filtrate tank, one part of the filtrate in the filtrate tank enters a flash evaporator through a filtrate pump to be subjected to flash evaporation and concentration, and the other part of the filtrate enters an OSLO crystallizer to be subjected to cooling crystallization; wherein the filtrate obtained by centrifugal separation in the bowl centrifuge contains MgSO 4 The mass concentration of (2) was 15%, the outer bowl of bowl centrifuge one was 2300rpm and the inner bowl was 2350rpm.
Further, in the step (8), the flash temperature in the flash evaporator is 80 ℃, and the heat insulation operation is performed.
Further, in the step (9), the crystallization temperature of the OSLO crystallizer is 25-30 ℃, and clear liquid enters a mother liquor tank through an overflow outlet pipeline; the crystal slurry enters the thickener through the crystal slurry outlet pipeline by gravity, the clear liquid of the thickener enters the mother liquor tank, and the crystal slurry concentrated by the thickener enters the rotary drum centrifuge II.
Further, in the step (10), the outer drum 2300rpm of the bowl centrifuge and the inner drum 2350rpm of the bowl centrifuge are used.
Further, the steps (9) and (10) further include: collecting the clear liquid overflowed from the OSLO crystallizer and the thickener into a mother liquor tank; then, one part of liquid in the mother liquid tank enters a flash evaporator for flash evaporation and concentration, and the other part enters an OSLO crystallizer for cooling and crystallization; and according to MgSO in flash liquid from flash evaporator 4 Concentration control into OSLO crystallizerThe amount of liquid, filtrate in the mother liquor tank of (a) ensures MgSO entering the OSLO crystallizer 4 The mass concentration of the slurry is 30%.
In the step (11), the crystallized filter cake centrifugally separated by the rotary drum centrifuge II enters a fluidized bed dryer for drying through a screw feeder, the fluidized bed dryer provides 80% of heat by a built-in calandria heater, hot air provides 20% of heat, the hot air is heated by an air heater and then is introduced into the fluidized bed dryer, the inlet temperature of the air heater is 25 ℃, the outlet temperature is 90-95 ℃, the temperature in the fluidized bed dryer is 50-55 ℃, and the material retention time is 0.75-1.0 h; the temperature of hot air discharged is 50-55 ℃, and the temperature of solid powder discharged is 45-50 ℃; hot air separated by the fluidized bed dryer enters a first oxidation tank and a second oxidation tank; the solid powder separated by the fluidized bed dryer, the cyclone separator and the bag filter enters a product bin.
Further, in the step (13), the solid powder separated by the fluidized bed dryer, the cyclone separator and the bag filter enters a product bin, and the solid powder is MgSO 4 ·7H 2 O product, mgSO in product bin 16 4 ·7H 2 O enters a product post-treatment system.
Compared with the prior art, the magnesium desulfurization device and method based on resource utilization have the beneficial effects that:
(1) The process flow is simple, continuous operation, high in automation degree, resource recycling and environment-friendly, and is used for realizing long-period stable operation of magnesium desulfurization; simultaneously recovering MgSO 3 Oxidative preparation of MgSO 4 ·7H 2 O，MgSO 4 ·7H 2 The O extraction rate is more than 90%, mgSO 4 ·7H 2 The mass content of O is more than or equal to 99 percent, which accords with the standard of GB/T2680-2009 primary products;
(2) The desulfurization raw material is 85 magnesia, and the batching water is mainly steam condensate water; the air and the heating source needed by the oxidation reaction are mainly hot air separated by a fluidized bed dryer; low-pressure water vapor which is flashed by a flash evaporator and is flashed by a flash tank is led in during digestion reactionGenerating secondary steam of 0.15MPa and 220 ℃ by MVR as main heating source of a fluidized bed dryer for digestion reaction, filtering and concentrating MgSO 3 Slurry was concentrated over evaporation MgSO 4 Solution, comprehensive energy saving is achieved by 50%;
(3) The digestion reaction, the oxidation reaction and the desulfurization reaction all adopt jet technology. Heat transfer and mass transfer are enhanced, the mixing effect of gas, liquid and solid is improved, and the production efficiency is improved.
Drawings
FIG. 1 is a schematic diagram of a magnesium desulfurization device based on resource utilization;
FIG. 2 is a flow chart of liquid in the mother liquor tank;
FIG. 3 is a top view of a baffle;
FIG. 4 is an odd-layer chevron tower profile;
FIG. 5 is an even-layered herringbone tower profile;
FIG. 6 is an elevation view of a chevron tower;
FIG. 7 is a left side view of a chevron tower;
FIG. 8 is a top view of a chevron tower;
FIG. 9 is an isometric view of a chevron tower;
FIG. 10 is a diagram of a spacer structure;
reference numerals: a digestion tank 1, a power fluid pump 1-1, a coupling distributor 1-2 and an ejector 1-3; flash tank 2, vapor compressor one 2-1, mechanical stirrer 2-2, mg (OH) 2 2-3 parts of a slurry pump; a flue gas heat exchanger 3; a flue gas dust collector 4; a chimney 5; a jet spray tank 6, a power fluid pump 6-1, a coupling distributor 6-2 and a jet ejector 6-3; the flue gas absorption tower 7, a demister cleaning spray head 7-1, a wire mesh demister 7-2, a filtering liquid spray head 7-3, a spray pipe and spray head 7-4, a tower plate 7-5, a baffle 7-6, a circulating slurry stirrer 7-7 and a circulating slurry pump 7-8; 7-9 of a supporting beam; 7-10 parts of white steel bars; the expansion drum filter 8, the filter bag 8-1, the concentrated magnesium sulfite slurry pump 8-2 and the filter liquid pump 8-3; an oxidation tank I9, a power fluid pump 9-1, a coupling distributor 9-2 and an ejector 9-3; an oxidation tank II 10, a power fluid pump 10-1, a coupling distributor 10-2, an ejector 10-3 and an oxidation slurry pump 10-4; first rotary drum centrifuge 11, spiral feeder 11 -1, filtrate tank 11-2, filtrate pump 11-3; flash evaporator 12, heater 12-1, vapor compressor two 12-2; OSLO crystallizer 13, thickener 13-1, mother liquor tank 13-2, mother liquor pump 13-3; a second bowl centrifuge 14, a screw discharger 14-1; a fluidized bed dryer 15, a cyclone separator 15-1, a bag filter 15-2, an air heater 15-3, a built-in calandria heater 15-4, a condensate water tank 15-5 and a condensate water pump 15-6; a product silo 16.
Detailed Description
The present invention will be described in further detail with reference to the following examples in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Example 1
As shown in fig. 1 and 2, the invention provides a magnesium desulfurization device based on resource utilization, which comprises a digestion tank 1, a flash tank 2, a jet spray tank 6, a flue gas absorption tower 7, a bulge drum filter 8, an oxidation tank I9, an oxidation tank II 10, a rotary drum centrifuge I11, a flash evaporator 12, an OSLO crystallizer 13, a rotary drum centrifuge II 14, a fluidized bed dryer 15 and a product bin 16 which are connected in sequence; wherein the flue gas heat exchanger 3 and the flue gas dust remover 4 are connected in sequence; the flue gas absorption tower 7, the flue gas heat exchanger 3 and the chimney 5 are connected in sequence;
The desulfurization device also comprises a first vapor compressor and a second vapor compressor; the first vapor compressor 2-1 is connected with a flash evaporation gas outlet pipeline of the flash evaporation tank 2, and the first vapor compressor boosts low-pressure steam obtained by flash evaporation of the flash evaporation tank and heats the low-pressure steam into secondary water vapor which is used as a main heat source of the digestion tank 1 to enter the digestion tank; the second vapor compressor 12-2 is connected with a vapor outlet pipeline of the flash evaporator 12, and the second vapor compressor boosts and heats the vapor flashed by the flash evaporator into secondary vapor serving as a main heat source of the fluidized bed dryer 15;
the desulfurization apparatus further includes: the cyclone separator 15-1 and the bag filter 15-2 are used for separating solid powder contained in hot air discharged from the fluidized bed dryer 15, the separated solid powder enters a product bin, and the separated hot air is used as an auxiliary heat source to be conveyed to the first oxidation tank 9 and the second oxidation tank 10.
The desulfurization apparatus further includes: the fluidized bed dryer 15 is provided with heat by hot air generated by the built-in calandria heater 15-4 and the air heater 15-3, the built-in calandria heater and the air heater use steam as a heat source, the condensed water tank is used for collecting steam condensate water generated by the steam which is introduced into the heater of the flash evaporator 12, the air heater of the fluidized bed dryer 15 and the built-in calandria heater, and the collected condensate water is conveyed to the digestion tank 1 through the condensate water pump 15-6 to serve as water for ingredients.
The desulfurization device also comprises a flue gas heat exchanger 3, a flue gas dust remover 4 and a chimney 5; the flue gas heat exchanger is respectively connected with a flue gas inlet pipeline of the power plant, a desulfurization flue gas inlet pipeline, a flue gas outlet pipeline of the power plant and a desulfurization flue gas outlet pipeline; the desulfurization flue gas in the flue gas absorption tower 7 enters a flue gas heat exchanger through a desulfurization flue gas inlet pipeline, and is discharged after being heated and enters a chimney through a desulfurization flue gas outlet pipeline; the flue gas of the power plant enters the flue gas heat exchanger through a flue gas inlet pipeline of the power plant, and then enters the flue gas dust remover through a flue gas outlet pipeline of the power plant; the flue gas dust remover is respectively connected with a cooled power plant flue gas inlet pipeline, a dust removal flue gas outlet pipeline and a dust discharge outlet pipeline; after entering a flue gas dust remover, the cooled power plant flue gas enters a dust discharge treatment system through a dust discharge outlet pipeline, and the dust-removed flue gas enters a jet spray tank 6 through a dust removal flue gas outlet pipeline for desulfurization;
the water vapor mainly provides auxiliary heat sources for the digestion tank, the oxidation tank I, the oxidation tank II and the fluidized bed dryer, and provides heat sources for a heater of the flash evaporator; the main heat sources of the oxidation tank I and the oxidation tank II are provided by hot air exhausted by a fluidized bed dryer, the main heat sources of the digestion tank are provided by secondary steam which is generated by a flash tank and is compressed by mechanical steam, namely, boosted and heated by a compressor, the fluidized bed dryer is provided by 80% of heat by a built-in calandria heater, and the hot air is provided with 20% of heat, so that a great amount of power cost can be saved, the hot air is heated by an air heater and then is introduced into the fluidized bed dryer, and the hot air can fluidize powder in the fluidized bed dryer; the main heat sources of the air heater and the built-in calandria heater are water vapor generated by a flash evaporator and are recompressed by mechanical vapor, namely, secondary water vapor for boosting and heating by a compressor is provided, and the auxiliary heat source is water vapor; the digestion tank uses condensed water as main water for ingredients and uses process water as auxiliary water; the water vapor is 0.4MPa of common engineering, the temperature of 230 ℃ of the water vapor is 220 ℃ of the secondary water vapor, and the pressure of the superheated water vapor is 0.15 MPa.
The digestion tank 1 is respectively connected with a condensed water feeding pipeline, a MgO feeding pipeline, a process water feeding pipeline, a water vapor inlet pipeline and Mg (OH) 2 The digestion tank adopts a jet stirrer, the jet stirrer is connected with a power fluid pump 1-1, and the structure of the digestion tank comprises a coupling distributor 1-2 and a jet device 1-3; the power fluid pump 1-1 is composed of a centrifugal pump, a slurry suction pipe and a slurry discharge pipe; the coupling distributor 1-2 is respectively composed of a slurry inlet pipe, a slurry distribution cavity, a water vapor suction pipe and a water vapor distribution cavity; the ejector 1-3 consists of a power slurry inlet, a guide ring, a power slurry nozzle, a water vapor suction inlet, a mixing cavity, a diffusion cavity and a slurry outlet; the ejector 1-3 is connected with the coupling distributor 1-2; the power fluid pump 1-1 absorbs the slurry in the digestion tank 1, the slurry enters a slurry distribution cavity of the coupling distributor 1-2 through a pipeline after being boosted by an impeller of the power fluid pump 1-1, and the slurry distributed by the distribution cavity is sprayed out through a power nozzle of the ejector 1-3 to form high-speed fluid; at this time, the kinetic energy of the fluid is maximum and the potential energy is minimum, so that negative pressure is generated at the water vapor suction inlet, and the water vapor is sucked into the coupling distributor 1-2; the sucked water vapor expands rapidly in the negative pressure area and is beaten into tiny bubbles by the power fluid, the water vapor and the slurry are fully mixed in the mixing cavity, and the micro-explosion effect of the water vapor in the mixing cavity peels off the Mg (OH) covered on the surfaces of MgO particles 2 Is favorable for MgO digestion, accelerates the discharge due to energy exchange, increases the potential energy of the mixed liquid through a diffusion cavity, and is emitted to the tank bottom in different directions by the power nozzles of the jet device 1-3, and the dragging effect of the fluid increases MgO digestion effect, mgO and H 2 O reacts to form Mg (OH) 2 And is cured; mg [ ]OH) 2 Slurry enters the flash tank 2 through an outlet pipeline by gravity;
the flash tanks 2 are respectively connected with Mg (OH) 2 Slurry inlet pipeline, flash vapor outlet pipeline and Mg (OH) 2 A slurry outlet pipeline, in which a mechanical stirrer 2-2 is adopted; the flash tank is also connected with a vapor compressor 2-1, low-pressure steam which is flashed in the flash tank is boosted and heated by the vapor compressor 1-2 to form secondary steam, and the secondary steam is taken as a main heat source to enter the digestion tank 1; mg (OH) after flash evaporation 2 The slurry is composed of Mg (OH) 2 The slurry pump 2-3 enters a jet spray tank 6;
the jet spray tanks 6 are respectively connected with Mg (OH) 2 The slurry inlet pipeline, the desulfurization flue gas inlet pipeline, the desulfurization slurry outlet pipeline and the desulfurization flue gas outlet pipeline are internally provided with a coupling distributor 6-2 and a jet device 6-3, and the coupling distributor 6-2 is connected with a power fluid pump 6-1; the power fluid pump 6-1 is composed of a centrifugal pump, a slurry suction pipe and a slurry discharge pipe; the coupling distributor 6-2 is respectively composed of a slurry inlet pipe, a slurry distribution cavity, a desulfurization flue gas suction pipe and a desulfurization flue gas distribution cavity; the ejector 6-3 consists of a power fluid inlet, a guide ring, a power slurry nozzle, a flue gas suction inlet, a mixing cavity, a diffusion cavity and a slurry outlet; the ejector 6-3 is connected with the coupling distributor 6-2; the power fluid pump 6-1 draws the slurry in the jet spray tank 6 and Mg (OH) from the flash tank 2 2 The slurry enters a slurry distribution cavity of the coupling distributor 6-2 through a pipeline after being boosted by an impeller of the power fluid pump 6-1, and the slurry distributed by the distribution cavity is sprayed out through a power nozzle of the ejector 6-3 to form high-speed fluid; at the moment, the kinetic energy of the fluid is the largest and the potential energy is the smallest, so that negative pressure is generated at the desulfurization flue gas suction inlet, and the desulfurization flue gas is sucked into the coupling distributor 6-2; the sucked desulfurization flue gas expands rapidly in the negative pressure area and is beaten into tiny bubbles by the power fluid, in the mixing cavity, the desulfurization flue gas and the slurry are fully mixed and are accelerated to be discharged due to energy exchange, the potential energy of the mixed liquid is increased through the diffusion cavity, and then the mixed liquid is emitted to the tank bottom through the power nozzle of the ejector 6-3, and the Mg (OH) is increased by the dragging action of the fluid 2 Is Mg(OH) 2 React with flue gas to generate MgSO 3 MgSO (MgSO) 4 The method comprises the steps of carrying out a first treatment on the surface of the The desulfurization flue gas enters the flue gas absorption tower 7 through an outlet pipeline, and the desulfurization slurry enters the flue gas absorption tower 7 through the outlet pipeline by gravity;
the flue gas absorption tower 7 is respectively connected with a desulfurization slurry inlet pipeline, a desulfurization flue gas inlet pipeline, two circulation slurry inlet pipelines, three filtering liquid inlet pipelines, a circulation slurry outlet pipeline and a desulfurization flue gas outlet pipeline, and is internally provided with two layers of demister cleaning spray heads 7-1, two layers of wire mesh demisters 7-2, a filtering liquid spray head 7-3, two layers of spray pipes and spray heads 7-4, two sections of tower plates 7-5, two layers of 45-degree annular baffles 7-6 (shown in figure 3), a circulation slurry mechanical stirrer 7-7 and a circulation slurry pump 7-8; the desulfurization flue gas escaping from the jet spray tank 6 enters two sections of tower plates 7-5, two layers of spray pipes and spray heads 7-4 of the flue gas absorption tower 7 to be in countercurrent contact with circulating slurry for continuous desulfurization; the tower plates can prevent slurry from blocking the tower plates, the annular baffle plates are arranged on the tower wall below each tower plate, the annular baffle plates are arranged at 45 degrees with the tower wall, the 45-degree annular baffle plates 7-6 can prevent the descending slurry from forming wall flow, and filtered liquid can wash out solid particles on the tower plates; the cleaning spray heads 7-1 of the two layers of the mist eliminators can remove water mist on the two layers of the wire mesh mist eliminators 7-2, so that water vapor carried by desulfurization flue gas is reduced; the desulfurization flue gas enters the flue gas heat exchanger 3 through an outlet pipeline, and the circulating slurry is pumped into the expansion drum filter 8 through the outlet pipeline by a part of the circulating slurry pump 7-8 and into the two layers of spray pipes and the spray heads 7-4;
Each section of tower plate comprises nine layers of herringbone tower pieces (the layer height is 300 mm) and nine layers of separating nets, wherein a plurality of groups of herringbone tower pieces in each layer are respectively and uniformly paved on the corresponding separating nets in the flue gas absorption tower, and the herringbone tower pieces in odd and even layers are staggered and uniformly distributed (as shown in fig. 4 and 5, the fig. 4 is an odd layer and the fig. 5 is an even layer); wherein the herringbone tower member is composed of angle steel; two 50mm multiplied by 5mm angle steel ridge lines with the length of 200mm are connected upwards and end heads and welded into a right-angle-shaped member, three right-angle-shaped members and apex angles are upwards and welded into a group of herringbone tower pieces in a surrounding way of regular triangle (the front view, the left view, the top view and the axial side view of the herringbone tower pieces are shown in figures 6-9 respectively); the separation net is composed of a supporting beam 7-9 and a white steel bar 7-10 (shown in figure 10) passing through the supporting beam.
The expansion drum filter 8 is respectively connected with a circulating slurry inlet pipeline, a filtered liquid outlet pipeline and a concentrated MgSO 3 A slurry outlet pipeline, in which a filter bag 8-1 is arranged, and the filtered liquid enters a filtered liquid spray head 7-3 and a two-layer demister cleaning spray head 7-1 through a filtered liquid pump 8-3, and is concentrated with MgSO 3 The slurry was concentrated MgSO via an outlet line 3 The slurry pump 8-2 enters the first oxidation tank 9;
the first oxidation tank 9 is respectively connected with a concentrated MgSO 3 Slurry inlet line, catalyst inlet line, hot air inlet line, fresh air inlet line, steam inlet line, exhaust gas discharge outlet line, mgSO 4 The solution outlet pipeline, the oxidation tank I adopts a jet mixer, the jet mixer is connected with a power fluid pump 9-1, and the structure of the oxidation tank I comprises a coupling distributor 9-2 and a jet mixer 9-3; the power fluid pump 9-1 is composed of a centrifugal pump, a slurry suction pipe and a slurry discharge pipe; the coupling distributor 9-2 is respectively composed of slurry [ catalyst, mgSO 3 、MgSO 4 、Mg(OH) 2 Water of]The slurry distributor comprises an inlet pipe, a slurry distribution cavity, a gas (hot air, fresh air and water vapor) suction pipe and a gas distribution cavity; the ejector 9-3 consists of a power fluid inlet, a guide ring, a power slurry nozzle, a gas suction inlet, a mixing cavity, a diffusion cavity and a slurry outlet; the ejector 9-3 is connected with the coupling distributor 9-2; the power fluid pump 9-1 absorbs the slurry in the first oxidation tank 9, the slurry enters a slurry distribution cavity of the coupling distributor 9-2 through a pipeline after being boosted by an impeller of the power fluid pump 9-1, and the slurry distributed by the distribution cavity is sprayed out through a power nozzle of the ejector 9-3 to form high-speed fluid; at this time, the kinetic energy of the fluid is maximum and the potential energy is minimum, so that negative pressure is generated at the gas suction inlet, and the gas is sucked into the coupling distributor 9-2; the sucked gas expands rapidly in the negative pressure area and is beaten into tiny bubbles by the power fluid, in the mixing cavity, the gas and the slurry are fully mixed and are accelerated to be discharged due to energy exchange, the potential energy of the mixed liquid is increased through the diffusion cavity, then the mixed liquid is sent to the tank bottom in multiple directions by the power nozzle of the ejector 9-3, and the MgSO is increased due to the dragging action of the fluid 3 Is MgSO 3 React with oxygen to form MgSO 4 The method comprises the steps of carrying out a first treatment on the surface of the The exhaust gas is discharged and enters the exhaust gas treatment system through an outlet pipeline, and the oxidation slurry enters the oxidation tank II 10 through the outlet pipeline by gravity;
the second oxidation tank 10 is respectively connected with an oxidation slurry inlet pipeline, a hot air inlet pipeline, a fresh air inlet pipeline, a water vapor inlet pipeline, a filter residue inlet pipeline, a impurity removing agent inlet pipeline, a flocculating agent inlet pipeline, a decoloring agent inlet pipeline, an exhaust gas discharge outlet pipeline and an oxidation slurry outlet pipeline, and adopts a jet stirrer which is connected with the power fluid pump 10-1 and structurally comprises a coupling distributor 10-2 and a jet device 10-3; the power fluid pump 10-1 is composed of a centrifugal pump, a slurry suction pipe and a slurry discharge pipe; the coupling distributor 10-2 is composed of slurry [ catalyst, mgSO 3 、MgSO 4 、Mg(OH) 2 Water of]The slurry distributor comprises an inlet pipe, a slurry distribution cavity, a gas (hot air, fresh air and water vapor) suction pipe and a gas distribution cavity; the ejector 10-3 consists of a power fluid inlet, a guide ring, a power slurry nozzle, a gas suction inlet, a mixing cavity, a diffusion cavity and a slurry outlet; the ejector 10-3 is connected with the coupling distributor 10-2; the power fluid pump 10-1 absorbs the slurry in the second oxidation tank 10, the slurry enters a slurry distribution cavity of the coupling distributor 10-2 through a pipeline after being boosted by an impeller of the power fluid pump 10-1, and the slurry distributed by the distribution cavity is sprayed out through a power nozzle of the ejector 10-3 to form high-speed fluid; at this time, the kinetic energy of the fluid is maximum and the potential energy is minimum, so that negative pressure is generated at the gas suction inlet, and the gas is sucked into the coupling distributor 10-2; the sucked gas expands rapidly in the negative pressure area and is beaten into micro bubbles by the power fluid, in the mixing cavity, the gas and the slurry are fully mixed and are accelerated to be discharged due to energy exchange, the potential energy of the mixed liquid is increased through the diffusion cavity, then the mixed liquid is emitted to the tank bottom in multiple directions by the power nozzle of the ejector 10-3, and the MgSO is increased due to the dragging action of the fluid 3 Is MgSO 3 React with oxygen to form MgSO 4 The method comprises the steps of carrying out a first treatment on the surface of the Exhaust gas is discharged and enters the exhaust gas treatment system through the outlet pipeline, and the oxidation slurry is led through the outlet pipelineThe peroxide slurry pump 10-4 enters a first rotary drum centrifuge 11;
the first rotary drum centrifuge 11 is respectively connected with an oxidized slurry inlet pipeline, an outlet pipeline of the second filter residue oxidation removal tank 10, a filter residue discharge outlet pipeline and a filtrate outlet pipeline; part of filter residues separated by the rotary drum centrifuge I11 enter the oxidation tank II 10 through the spiral feeder 11-1, and part of filter residues enter a waste residue treatment system through a filter residue discharge outlet pipeline; the separated filtrate enters a filtrate tank 11-2, then part of the filtrate enters a heater 12-1 of a flash evaporator 12 through a filtrate pump 11-3, and part of the filtrate enters an OSLO crystallizer 13;
the flash evaporator 12 is respectively connected with a heating filtrate, a mother liquor tank liquid inlet pipeline, a steam outlet pipeline and a flash liquor outlet pipeline; the filtrate from the filtrate tank 11-2 and the liquid from the mother liquor tank 13-2 enter a heater 12-1 for heating, the heated filtrate and mother liquor enter a flash evaporator 12, the flash steam enters a second vapor compressor 12-2 to generate secondary steam, and the secondary steam enters an air heater 15-3 of the fluidized bed dryer 15 and a built-in calandria heater of the fluidized bed dryer; the flash liquid enters the OSLO crystallizer 13 by gravity through an outlet line;
The OSLO crystallizer 13 is respectively connected with a flash liquid inlet pipeline, a filtrate inlet pipeline, a mother liquor tank liquid inlet pipeline, a clear liquid overflow outlet pipeline and a crystal slurry outlet pipeline; the flash evaporation liquid, filtrate and liquid in the mother liquor tank enter an OSLO crystallizer 13 for cooling crystallization, clear liquid enters a mother liquor tank 13-2 through an overflow outlet pipeline, crystal slurry enters a thickener 13-1 through a crystal slurry outlet pipeline by gravity, clear liquid of the thickener 13-1 enters the mother liquor tank 13-2, crystal slurry concentrated by the thickener 13-1 enters a rotary drum centrifuge II 14, and liquid in the mother liquor tank enters a flash evaporator 12 and the OSLO crystallizer 13 through a mother liquor pump 13-3;
the rotary drum centrifuge II 14 is respectively connected with a crystal slurry inlet pipeline, a crystal filter cake outlet pipeline and a mother liquor outlet pipeline; the crystal slurry enters a rotary drum centrifuge II 14, mother liquor after centrifugal separation enters a mother liquor tank 13-2 through an outlet pipeline, and a crystal filter cake enters a fluidized bed dryer 15 through an outlet pipeline through a spiral discharger 14-1;
the fluidized bed dryer 15 is respectively connected with a crystallization filter cake inlet pipeline, a hot air outlet pipeline and a powder outlet pipeline; the air is heated by an air heater 15-3 and then enters a fluidized bed dryer 15 to dry the crystallization filter cake; the secondary water vapor is a main heat source of an air heater 15-3 and a built-in calandria heater 15-4, condensed water is collected in a condensed water tank 15-5, and enters the digestion tank 1 through a condensed water pump 15-6; the fluidized bed dryer 15 is sequentially connected with the cyclone separator 15-1 and the bag filter 15-2, hot air discharged by the fluidized bed dryer 15 is separated by the cyclone separator 15-1 and the bag filter 15-2 and then enters the first oxidation tank 9 and the second oxidation tank 10, and products enter the product bin 16 through a product outlet pipeline by gravity;
The product bin 16 includes a product inlet line and MgSO 4 ·7H 2 An O outlet line; mgSO (MgSO) 4 ·7H 2 O enters the product post-treatment system through an outlet pipeline.
The jet stirrer adopted by the invention consists of a plurality of jet devices and a coupling distributor, the power fluid passes through the nozzle to form high-speed fluid, the kinetic energy of the fluid is the largest at the moment, the potential energy is the smallest, negative pressure is generated at the gas suction inlet, then the gas is sucked, the sucked gas is rapidly expanded in the negative pressure area and is beaten into tiny bubbles by the power fluid, and in the mixing cavity, the gas (water vapor, CO) 2 Hot air), water and magnesium oxide powder are fully mixed, fluid is subjected to intensive mixing and stirring in a mixing zone, the fluid is accelerated to be discharged due to energy exchange, potential energy of the mixed fluid is increased to the maximum value through a diffusion cavity, the mixed fluid is emitted to the bottom of the tank in a tangential direction, and the mixing and stirring effect is further enhanced due to the dragging effect of the mixed fluid. The gas is sucked into the digestion tank by the jet mixing stirrer, and high-speed jet flow of 300m/s can be generated in a gas-liquid mixing cavity of the jet mixing stirrer; the digestion reaction of water and raw MgO powder is facilitated; the same applies to the jet spray tank 6, the first oxidation tank 9 and the second oxidation tank 10.
When the production device is started, the digestion tank 1 adopts process water as batching water, the digestion tank 1, the oxidation tank I9 and the oxidation tank II 10 adopt water vapor as starting vapor (not shown in a starting piping diagram) until the whole production device normally operates, and when secondary water vapor is insufficient, the water vapor is also used as an auxiliary heating source of the digestion tank 1; when the hot air exhausted by the fluidized bed is insufficient, the water vapor is also used as an auxiliary heating source of the first oxidation tank 9 and the second oxidation tank 10; the devices of the invention are connected through corresponding pipelines, and when the pipelines in the figure 1 are crossed but are not crossed in practice, the pipelines are drawn according to the principle of continuous vertical and horizontal sections.
Example 2
The magnesium desulfurization method based on the device described in example 1 comprises the following steps:
(1) 18.194kg/h (magnesium-sulfur mole ratio is 1.02) of raw material 85 magnesium oxide (magnesium oxide mass fraction 85%) and 163.746kg/h of condensed water (process water) are fed into a digestion tank 1, and the initial mass concentration of MgO is 10%; the digestion temperature of the digestion tank 1 is 85 ℃, the pressure is 0.1MPa, the retention time of the materials in the digestion tank is 2.5h, the secondary steam is 220 ℃, and the pressure is 0.15MPa, and the digestion slurry is directly heated by being sucked in by a jet stirrer.
(2) Feeding the digested slurry in the digestion tank 1 into a flash tank 2, wherein the flash temperature in the flash tank 2 is 80 ℃, performing adiabatic operation, and feeding the flashed steam into a steam compressor 2-1; mg (OH) after flash evaporation 2 Diluting the slurry with process water to 3% by mass concentration, and mixing with Mg (OH) 2 The slurry pump 2-3 enters the jet spray tank 6.
(3) The temperature in the jet spray tank 6 is 50 ℃, the pressure is 0.45MPa, the residence time of the materials is 0.125h, and the pH value is controlled to be 6.5; 11329.85Nm of dedusting flue gas 3 /h, temperature 50 ℃, SO 2 Concentration of 2500mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the Dust-removing smoke sucked into the smoke dust remover 4 by the coupling distributor 6-2 of the jet spray tank 6 is subjected to intensified desulfurization in the jet spray tank 6;
(4) The temperature in the flue gas absorption tower 7 is 55 ℃, the pressure is 0.10MPa, the residence time of the desulfurized flue gas is 10s, the gas velocity is 3m/s, the pH value is controlled to be 5.8, and the liquid-gas ratio is 6L/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The desulfurization flue gas escaping from the jet spray tank 6 is continuously desulfurized in the flue gas absorption tower 7;
wherein: the flue gas heat exchanger 3 exchanges heat between the power plant flue gas and the desulfurization flue gas; the flue gas inlet temperature of the power plant is 125 ℃, the pressure is 0.1MPa, and the SO is generated 2 Concentration 2500mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The inlet temperature of the desulfurization flue gas is 50 ℃, the pressure is 0.1MPa, and the SO is the same as that of the desulfurization flue gas 2 Concentration of 25mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The outlet temperature of flue gas of a power plant is 85 ℃, and the outlet temperature of desulfurization flue gas is 80 ℃; the desulfurization flue gas enters a chimney 5 for high-altitude discharge after the temperature of the flue gas heat exchanger 3 is raised, and the temperature of the desulfurization flue gas entering the chimney 5 is 80 ℃; the cooled power plant flue gas of the flue gas heat exchanger 3 enters the flue gas dust remover 4 for dust removal, the inlet temperature of the power plant flue gas is 85 ℃, the outlet temperature of the dust removal flue gas is 50 ℃, dust enters the dust discharge system through the dust discharge outlet pipeline, and the dust removal flue gas enters the jet spray tank 6 through the dust removal flue gas outlet pipeline.
(5) The filtering liquid in the filter bag of the bulge drum filter 8 enters the flue gas absorption tower 7 to wash the desulfurization flue gas and flush the solid particles on the herringbone tower plate, and MgSO is arranged outside the filter bag 3 The slurry was concentrated from 2% by mass to 11% and passed through a pump 8-2 into an oxidation tank one 9.
(6) Adding a catalyst into the first oxidation tank 9, sucking hot air, fresh air and water vapor through a jet stirrer, wherein the temperature in the first oxidation tank 9 is 50 ℃, the pressure is 0.20MPa, and the material residence time is 3.5h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidizing slurry enters the second oxidizing tank 10, and the exhaust gas (which can take away part of the water vapor) enters the exhaust gas treatment system through an exhaust gas discharge pipeline.
(7) Adding part of filter residues, a purifying agent, a flocculating agent and a decolorizing agent which are centrifugally separated by the first rotary drum centrifuge 11 into the second oxidation tank 10, sucking hot air, fresh air and water vapor by a jet mixer, wherein the temperature in the second oxidation tank 10 is 50 ℃, the pressure is 0.15MPa, and the material residence time is 3.5 hours; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidized slurry enters a first rotary drum centrifuge 11, and the exhaust gas (which can take away part of water vapor) enters an exhaust gas treatment system through an exhaust gas discharge pipeline.
(8) Feeding oxidized slurry in the second oxidation tank 10 into the first rotary drum centrifuge 11 through an oxidized slurry pump 10-4 for centrifugal separation, feeding part of separated filter residues into the second oxidation tank 10 for continuous oxidation, and feeding the other part of filter residues into a filter residue treatment system; the filtrate separated by the first rotary drum centrifuge 11 enters a filtrate tank 11-2 for filtration The liquid enters a flash evaporator 12 for flash evaporation concentration through a part of a filtrate pump 11-3, and enters an OSLO crystallizer 13 for cooling crystallization; the filtrate contains MgSO 4 15% by mass, the outer drum of bowl centrifuge one 11 was 2300rpm and the inner drum was 2350rpm.
(9) The filtrate (and the liquid in the mother liquor tank) separated by the rotary drum centrifuge I11 enters a heater 12-1, is heated to 80 ℃ and enters a flash evaporator 12 for flash evaporation and concentration, low-pressure water vapor is flashed out, and is compressed into secondary water vapor by a vapor compressor 12-2 to be used as a main heat source of an air heater 15-3 of the fluidized bed dryer 15; the flash temperature in the flash evaporator 12 is 80 ℃, and the adiabatic operation is carried out; the flash liquid contains MgSO 4 30% by mass, and then introduced into the OSLO crystallizer 13 to be cooled and crystallized.
(10) The flash liquid (filtrate and liquid in the mother liquor tank) in the flash evaporator 12 enters the OSLO crystallizer 13 for cooling crystallization, the crystallization temperature is 25 ℃, and clear liquid enters the mother liquor tank 13-2 through an overflow outlet pipeline; the crystal slurry enters the thickener 13-1 through the crystal slurry outlet pipeline by gravity, the clear liquid of the thickener 13-1 enters the mother liquor tank 13-2, and the crystal slurry concentrated by the thickener 13-1 enters the drum centrifuge II 14.
(11) The crystal slurry concentrated by the thickener 13-1 enters a rotary drum centrifuge II 14 for centrifugal separation, the separated mother liquor enters a mother liquor tank 13-2, and the separated crystal filter cake enters a fluidized bed dryer 15; outer drum 2300rpm of drum centrifuge two 14, inner drum 2350rpm; the water content of the crystalline filter cake was 5% (wet basis).
(12) The crystallized filter cake centrifugally separated by the rotary drum centrifuge II 14 enters a fluidized bed dryer 15 through a screw feeder 14-1 to be dried, the inlet temperature of an air heater 15-3 is 25 ℃, the outlet temperature is 90 ℃, the temperature in the fluidized bed dryer 15 is 50 ℃, and the material residence time is 1.0h; the temperature of the discharged hot air is 50 ℃, the temperature of the discharged solid powder is 45 ℃, 109.910kg/h of the discharged solid powder is 0.5 percent (wet basis) of the water content of the solid powder; hot air separated by the fluidized bed dryer 15 enters the first oxidation tank 9 and the second oxidation tank 10; the solid powder separated by the fluidized bed dryer 15, the cyclone 15-1 and the bag filter 15-2 enters the product bin 16.
(13) The solid powder dried by the 109.910kg/h fluidized bed dryer 15 enters a product bin 16, and the solid powder is MgSO 4 ·7H 2 O product, mgSO in product bin 16 4 ·7H 2 O enters a product post-treatment system.
Example 3
The desulfurization method based on the apparatus of example 1, comprising the steps of:
(1) 20.028kg/h (magnesium-sulfur mole ratio is 1.02) of raw material 85 magnesium oxide (magnesium oxide mass fraction 85%) and 180.253kg/h of condensed water (process water) are fed into a digestion tank 1, and the initial mass concentration of MgO is 10%; the digestion temperature of the digestion tank 1 is 90 ℃, the pressure is 0.1MPa, the retention time of the materials in the digestion tank is 2.5h, the secondary steam is 220 ℃, and the pressure is 0.15MPa, and the digestion slurry is directly heated by being sucked in by a jet stirrer.
(2) Feeding the digested slurry in the digestion tank 1 into a flash tank 2, wherein the flash temperature in the flash tank 2 is 80 ℃, performing adiabatic operation, and feeding the flashed steam into a steam compressor 2-1; mg (OH) after flash evaporation 2 Diluting the slurry with process water to 3% by mass concentration, and mixing with Mg (OH) 2 The slurry pump 2-3 enters the jet spray tank 6.
(3) The temperature in the jet spray tank 6 is 55 ℃, the pressure is 0.45MPa, the residence time of the materials is 0.25h, and the pH value is controlled to be 6.75; 11330.85Nm of dedusting flue gas 3 /h, temperature 55 ℃, SO 2 Concentration of 2750mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The dedusting smoke sucked into the smoke deduster 4 by the coupling distributor 6-2 of the jet spray tank 6 is subjected to intensified desulfurization in the jet spray tank 6.
(4) The temperature in the flue gas absorption tower 7 is 50 ℃, the pressure is 0.10MPa, the residence time of the desulfurized flue gas is 10s, the gas velocity is 3m/s, the pH value is controlled to be 6.5, and the liquid-gas ratio is 7L/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The desulfurization flue gas escaping from the jet spray tank 6 is continuously desulfurized in the flue gas absorption tower 7;
wherein: the flue gas heat exchanger 3 exchanges heat between the power plant flue gas and the desulfurization flue gas; the flue gas inlet temperature of the power plant is 130 ℃, the pressure is 0.1MPa, and SO is achieved 2 Concentration of 2750mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The inlet temperature of the desulfurized flue gas is 55 DEG CPressure 0.1MPa, SO 2 Concentration of 27.5mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The temperature of the flue gas outlet of the power plant is 90 ℃, and the temperature of the flue gas outlet of the desulfurization is 85 ℃; the desulfurization flue gas enters a chimney 5 for high-altitude discharge after the temperature of the flue gas heat exchanger 3 is raised, and the temperature of the desulfurization flue gas entering the chimney 5 is 85 ℃; the cooled power plant flue gas of the flue gas heat exchanger 3 enters the flue gas dust remover 4 for dust removal, the inlet temperature of the power plant flue gas is 90 ℃, the outlet temperature of the dust removal flue gas is 55 ℃, dust enters the dust discharge system through the dust discharge outlet pipeline, and the dust removal flue gas enters the jet spray tank 6 through the dust removal flue gas outlet pipeline.
(5) The filtering liquid in the filter bag of the bulge drum filter 8 enters the flue gas absorption tower 7 to wash the desulfurization flue gas and flush the solid particles on the herringbone tower plate, and MgSO is arranged outside the filter bag 3 The slurry was concentrated from 2% by mass to 11% and passed through a pump 8-2 into an oxidation tank one 9.
(6) Adding a catalyst into the first oxidation tank 9, sucking hot air, fresh air and water vapor through a jet stirrer, wherein the temperature in the first oxidation tank 9 is 55 ℃, the pressure is 0.20MPa, and the material residence time is 4.0h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidizing slurry enters the second oxidizing tank 10, and the exhaust gas (which can take away part of the water vapor) enters the exhaust gas treatment system through an exhaust gas discharge pipeline.
(7) Adding part of filter residues, a purifying agent, a flocculating agent and a decolorizing agent which are centrifugally separated by the first rotary drum centrifuge 11 into the second oxidation tank 10, sucking hot air, fresh air and water vapor by a jet mixer, wherein the temperature in the second oxidation tank 10 is 55 ℃, the pressure is 0.15MPa, and the material residence time is 4.0h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidized slurry enters a first rotary drum centrifuge 11, and the exhaust gas (which can take away part of water vapor) enters an exhaust gas treatment system through an exhaust gas discharge pipeline.
(8) The slurry oxidized in the second oxidation tank 10 enters the first rotary drum centrifuge 11 through the oxidized slurry pump 10-4 for centrifugal separation, half of the separated filter residues enter the second oxidation tank 10 for continuous oxidation, and the other part of the filter residues enter the filter residue treatment system; the filtrate separated by the first rotary drum centrifuge 11 enters a filtrate tank 11-2, and the filtrate enters a flash evaporator 12 for carrying out the treatment through a filtrate pump 11-3Flash evaporation concentration is carried out, and part of the concentrated solution enters an OSLO crystallizer 13 to be cooled and crystallized; the filtrate contains MgSO 4 15% by mass, the outer drum of bowl centrifuge one 11 was 2300rpm and the inner drum was 2350rpm.
(9) The filtrate (and the liquid in the mother liquor tank) separated by the rotary drum centrifuge I11 enters a heater 12-1, is heated to 80 ℃ and enters a flash evaporator 12 for flash evaporation and concentration, low-pressure water vapor is flashed out, and is compressed into secondary water vapor by a vapor compressor 12-2 to be used as a main heat source of an air heater 15-3 of the fluidized bed dryer 15; the flash temperature in the flash evaporator 12 is 80 ℃, and the adiabatic operation is carried out; the flash liquid contains MgSO 4 30% by mass, and then introduced into the OSLO crystallizer 13 to be cooled and crystallized.
(10) The flash liquid (filtrate and liquid in the mother liquor tank) in the flash evaporator 12 enters the OSLO crystallizer 13 for cooling crystallization, the crystallization temperature is 30 ℃, and clear liquid enters the mother liquor tank 13-2 through an overflow outlet pipeline; the crystal slurry enters the thickener 13-1 through the crystal slurry outlet pipeline by gravity, the clear liquid of the thickener 13-1 enters the mother liquor tank 13-2, and the crystal slurry concentrated by the thickener 13-1 enters the drum centrifuge II 14.
(11) The crystal slurry concentrated by the thickener 13-1 enters a rotary drum centrifuge II 14 for centrifugal separation, the separated mother liquor enters a mother liquor tank 13-2, and the separated crystal filter cake enters a fluidized bed dryer 15; outer drum 2300rpm of drum centrifuge two 14, inner drum 2350rpm; the water content of the crystalline filter cake was 5% (wet basis).
(12) The crystallized filter cake centrifugally separated by the rotary drum centrifuge II 14 enters a fluidized bed dryer 15 through a screw feeder 14-1 to be dried, the inlet temperature of an air heater 15-3 is 25 ℃, the outlet temperature is 95 ℃, the temperature in the fluidized bed dryer 15 is 55 ℃, and the material residence time is 0.75h; the temperature of the discharged hot air is 55 ℃, the temperature of the discharged solid powder is 50 ℃, 114.399kg/h of the discharged solid powder is 0.5 percent (wet basis) of the water content of the solid powder; hot air separated by the fluidized bed dryer 15 enters the first oxidation tank 9 and the second oxidation tank 10; the solid powder separated by the fluidized bed dryer 15, the cyclone 15-1 and the bag filter 15-2 enters the product bin 16.
(13) 114.399kg/h of flowThe solid powder dried by the fluidized bed dryer 15 enters a product bin 16, and the solid powder is MgSO 4 ·7H 2 O product, mgSO in product bin 16 4 ·7H 2 O enters a product post-treatment system.
In the magnesium desulfurization method based on resource utilization, the MVR generates secondary steam as a heating source, so that the comprehensive energy is saved by 50%; mgSO (MgSO) 4 ·7H 2 The O extraction rate is more than 90%, mgSO 4 ·7H 2 The mass content of O is more than or equal to 99 percent, which accords with the standard of GB/T2680-2009 primary products.
The technical scheme of the invention is explained in the technical scheme, the protection scope of the invention cannot be limited by the technical scheme, and any changes and modifications to the technical scheme according to the technical substance of the invention belong to the protection scope of the technical scheme of the invention.
Claims (9)
1. A magnesium desulfurization method based on resource utilization is characterized in that: the method specifically comprises the following steps:
(1) MgO and water enter a digestion tank, and secondary steam is sucked by a jet stirrer and directly heated to perform digestion reaction to generate Mg (OH) 2 Slurry;
(2) Mg (OH) in digestion tank 2 The slurry enters a flash tank, and the flash low-pressure steam is subjected to mechanical steam recompression (MVR) through a steam compressor, namely, secondary steam with pressure boosting and temperature rising of the compressor provides a main heat source for a digestion tank;
(3) Mg (OH) after flash evaporation in flash tank 2 Diluting the slurry with process water, entering a jet spray tank, absorbing dust-removing flue gas through a coupling distributor, and performing jet spray enhanced desulfurization in the jet spray tank;
(4) The desulfurization slurry and the desulfurization flue gas of the jet spray tank enter a flue gas absorption tower, the desulfurization slurry forms circulating slurry in the tower, and the desulfurization flue gas is in countercurrent contact with the circulating slurry in the flue gas absorption tower to continuously desulfurize; part of circulating slurry enters a bulge filter, filtering liquid in a filter bag of the bulge filter enters a flue gas absorption tower for washing and removingSulfur flue gas is concentrated outside the filter bag of the expansion drum filter to obtain MgSO 3 Slurry;
(5) Concentrated MgSO in a drum filter 3 The slurry enters into an oxidation tank I, and catalyst, hot air, fresh air and water vapor are added at the same time, mgSO 3 Oxidation reaction is carried out to generate MgSO 4 ；
(6) The oxidized slurry in the first oxidizing tank enters the second oxidizing tank by gravity, and simultaneously, impurity removing agent, flocculating agent, decoloring agent, hot air, fresh air and water vapor are added, mgSO 3 Oxidation reaction is carried out to generate MgSO 4 ；
(7) The slurry oxidized in the second oxidation tank enters the first rotary drum centrifuge for centrifugal separation, and the filtrate obtained by centrifugal separation enters a flash evaporator for flash evaporation and concentration through one part of the filtrate tank, and enters an OSLO crystallizer for cooling and crystallization through the other part of the filtrate tank;
(8) The filtrate centrifugally separated by the rotary drum centrifuge II enters a flash evaporator through a filtrate tank to be subjected to flash evaporation concentration, and the low-pressure steam obtained by flash evaporation is compressed into secondary steam by a steam compressor to be used as a main heat source of the fluidized bed dryer;
(9) The filtrate and flash liquid enter an OSLO crystallizer for cooling crystallization, the crystal slurry enters a thickener through a crystal slurry outlet pipeline by gravity, and the crystal slurry concentrated by the thickener enters a rotary drum centrifuge II;
(10) The crystal slurry concentrated by the thickener enters a rotary drum centrifuge II for centrifugal separation, and the separated crystal filter cake enters a fluidized bed dryer through a screw feeder;
(11) The crystallized filter cake centrifugally separated by the rotary drum centrifuge II enters a fluidized bed dryer for drying through a screw feeder; the hot air and the solid powder discharged from the fluidized bed dryer are separated into the solid powder and the hot air through a cyclone separator and a bag filter; the separated hot air enters a first oxidation tank and a second oxidation tank, and the separated solid powder and the solid powder dried by the fluidized bed dryer enter a product bin;
the desulfurization device adopted by the desulfurization method comprises a digestion tank, a flash tank, a jet spray tank, a flue gas absorption tower and a bulge drum filter which are connected in sequence The device comprises a device, a first oxidation tank, a second oxidation tank, a first rotary drum centrifuge, a flash evaporator, an OSLO crystallizer, a thickener, a second rotary drum centrifuge, a fluidized bed dryer and a product bin; the jet spray tank is used for obtaining Mg (OH) through digestion reaction and flash evaporation 2 Carrying out jet spray enhanced desulfurization on the slurry; the flue gas absorption tower is used for continuously desulfurizing the desulfurization slurry and the desulfurization flue gas obtained in the jet spray tank in a circulating countercurrent contact manner; the drum filter is used for concentrating MgSO 3 Slurry; concentrated MgSO 3 The MgSO is generated by the oxidation reaction of the first oxidation tank and the second oxidation tank 4 Slurry, mgSO 4 Separating the slurry by a rotary drum centrifuge I, enabling the separated filtrate to enter a flash evaporator for flash evaporation concentration, enabling the OSLO crystallizer to be used for cooling and crystallizing the flash evaporation concentrated slurry, enabling the obtained crystal slurry to enter a thickener for concentration, enabling the concentrated crystal slurry to enter a rotary drum centrifuge II for centrifugal separation, enabling the fluidized bed dryer to be used for drying the centrifugally separated crystal filter cake, and enabling the dried solid powder to enter a product bin;
the desulfurization device also comprises a first vapor compressor and a second vapor compressor; the vapor compressor is connected with a flash evaporation gas outlet pipeline of the flash evaporation tank, and the vapor compressor firstly boosts the low-pressure vapor flashed from the flash evaporation tank to secondary water vapor, and enters the digestion tank to serve as a main heat source of the digestion tank; the second steam compressor is connected with a steam outlet pipeline of the flash evaporator, and the second steam compressor boosts and heats the steam flashed by the flash evaporator into secondary steam serving as a main heat source of the fluidized bed dryer.
2. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: the desulfurization device also comprises a flue gas heat exchanger, a flue gas dust remover and a chimney; the flue gas heat exchanger is used for exchanging heat between the flue gas of the power plant and the desulfurization flue gas discharged by the flue gas absorption tower, the desulfurization flue gas heated after heat exchange enters a chimney and is discharged, the flue gas of the power plant after cooling enters a flue gas dust remover, and the obtained dedusting flue gas enters a jet spray tank for desulfurization;
wherein the temperature of a power plant flue gas inlet in the flue gas heat exchanger is 125-130 ℃ and the pressure is the same as the temperature of the power plant flue gas inlet0.1MPa，SO 2 Concentration of 2500mg/Nm 3 ～2750mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The inlet temperature of the desulfurization flue gas is 50-55 ℃, the pressure is 0.1MPa, and the SO is generated 2 Concentration of 25mg/Nm 3 ～27.5mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The temperature of the flue gas outlet of the power plant is 85-90 ℃, and the temperature of the flue gas outlet of the desulfurization is 80-85 ℃;
the temperature of the desulfurized flue gas entering a chimney is 80-85 ℃;
in the flue gas dust remover, the temperature of a flue gas inlet of a power plant is 85-90 ℃, and the temperature of a dust removing flue gas outlet is 50-55 ℃.
3. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: the flue gas absorption tower is provided with two sections of tower plates, a slurry spraying layer is arranged above the two sections of tower plates, an annular baffle is arranged on the tower wall below each section of tower plate, and the annular baffle and the tower wall are arranged at 45 degrees; two layers of demisters are arranged above the two sections of tower plates, and demister cleaning spray heads are arranged above each layer of demisters; a filtering liquid spray head is arranged between the two layers of demisters and the two sections of tower plates; the flue gas absorption tower is provided with a circulating slurry pipeline which is used for sucking desulfurization slurry in the flue gas absorption tower and conveying the desulfurization slurry to a slurry spraying layer and a bulge filter; and the filtering liquid spray head is connected with a filtering liquid outlet pipeline of the bulge filter.
4. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: each section of tower plate comprises nine layers of herringbone tower pieces and nine layers of separating nets, wherein a plurality of groups of herringbone tower pieces in each layer are respectively and uniformly paved on the corresponding separating nets in the flue gas absorption tower, and the herringbone tower pieces in odd and even layers are staggered and uniformly distributed; wherein the herringbone tower member is composed of angle steel; the two angle steel edges are connected upward and end-to-end, and welded into a right-angle-shaped member, and the three right-angle-shaped members and the apex angle upward are enclosed into a regular triangle and welded into a group of herringbone tower pieces; the separation net is composed of a supporting beam and a white steel bar penetrating through the supporting beam.
5. According to claim 1The magnesium desulfurization method based on resource utilization is characterized by comprising the following steps: the MgO in the step (1) is 85MgO which is obtained by classifying light burned magnesia, wherein the mass content of MgO is not less than 85%, the grain diameter is 95% less than 0.075mm, the digestion temperature in a digestion tank in the step (1) is 85-90 ℃, the pressure is 0.1MPa, the initial mass concentration of MgO is 10%, the residence time of materials in the digestion tank is 2.5-3 h, and secondary steam is sucked into a jet mixer to directly heat digestion slurry; in the step (2), the flash evaporation temperature in the flash tank 2 is 80 ℃, the operation is performed in an adiabatic mode, and the flash steam enters a steam compressor; mg (OH) after flash evaporation 2 Diluting the slurry with process water to Mg (OH) 2 The mass concentration is 3%, and the Mg (OH) 2 The slurry pump enters the jet spray tank.
6. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: in the step (3), the temperature in the jet spray tank is 50-55 ℃, the pressure is 0.45MPa, the retention time of materials is 0.125-0.25 h, and the pH value is controlled to be 6.5-6.75; the temperature of the dust-removing flue gas is 50-55 ℃ and SO 2 Concentration of 2500mg/Nm 3 ～2750mg/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The dust-removing flue gas which is sucked into the flue gas dust remover by the coupling distributor of the jet spray tank is subjected to intensified desulfurization in the jet spray tank; in the step (4), the temperature in the flue gas absorption tower is 50-55 ℃, the pressure is 0.10MPa, the residence time of the desulfurized flue gas is 10-12 s, the gas velocity is 3m/s, the pH value is controlled to be 5.8-6.5, and the liquid-gas ratio is 6L/Nm 3 ～7L/Nm 3 The method comprises the steps of carrying out a first treatment on the surface of the The desulphurized flue gas escaping from the jet spray tank is continuously desulphurized in the flue gas absorption tower.
7. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: in the step (5), the catalyst is added into a first oxidation tank, hot air, fresh air and water vapor are sucked through a jet stirrer, the temperature in the first oxidation tank is 50-55 ℃, the pressure is 0.20MPa, and the material residence time is 3.5-4.0 h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidation slurry enters a second oxidation tankThe waste gas enters the waste gas treatment system through a waste gas discharge pipeline; in the step (6), part of filter residues centrifugally separated by the rotary drum centrifuge I, a impurity removing agent, a flocculating agent and a decolorizing agent are added into the second oxidation tank, hot air, fresh air and water vapor are sucked through a jet mixer, the temperature in the second oxidation tank is 50-55 ℃, the pressure is 0.15MPa, and the material residence time is 3.5-4.0 h; mgSO (MgSO) 3 Oxidation to MgSO 4 The oxidized slurry enters a rotary drum centrifuge I, and the waste gas enters a waste gas treatment system through a waste gas discharge pipeline.
8. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: the step (7) further comprises: mgSO in the filtrate centrifugally separated by a rotary drum centrifuge 4 Adding one part of filter residues centrifugally separated by the rotary drum centrifuge I into the oxidation tank II for continuous oxidation, and adding the other part of filter residues into a filter residue treatment system; the steps (9) and (10) further comprise: collecting the clear liquid overflowed from the OSLO crystallizer and the thickener into a mother liquor tank; then, one part of liquid in the mother liquid tank enters a flash evaporator for flash evaporation and concentration, and the other part enters an OSLO crystallizer for cooling and crystallization; and according to MgSO in flash liquid from flash evaporator 4 Concentration, controlling the amount of liquid and filtrate in the mother liquor tank entering the OSLO crystallizer, ensuring MgSO entering the OSLO crystallizer 4 The mass concentration of the slurry is 30%.
9. The magnesium desulfurization method based on resource utilization according to claim 1, characterized in that: in the step (8), the flash evaporation temperature in the flash evaporator is 80 ℃, and the heat insulation operation is carried out; in the step (9), the crystallization temperature of the OSLO crystallizer is 25-30 ℃; in the step (11), the crystallized filter cake centrifugally separated by the rotary drum centrifuge II enters a fluidized bed dryer for drying through a screw feeder, the fluidized bed dryer provides 80% of heat by a built-in calandria heater, hot air provides 20% of heat, the hot air is heated by an air heater and then is introduced into the fluidized bed dryer, the outlet temperature is 90-95 ℃, the temperature in the fluidized bed dryer is 50-55 ℃, and the material retention time is 0.75-1.0 h; the temperature of the hot air discharged is 50-55 ℃, and the temperature of the solid powder discharged is 45-50 ℃.
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| JPH06142447A (en) * | 1992-11-02 | 1994-05-24 | Mitsubishi Heavy Ind Ltd | Treatment of gypsum slurry from wet stack gas desulfurizer |
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| CN113398750A (en) * | 2021-07-08 | 2021-09-17 | 西安钧泰环保设备工程有限公司 | Desulfurizing tower thick liquid pond subregion oxidation unit |
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| JPH06142447A (en) * | 1992-11-02 | 1994-05-24 | Mitsubishi Heavy Ind Ltd | Treatment of gypsum slurry from wet stack gas desulfurizer |
| CN101530725A (en) * | 2009-03-11 | 2009-09-16 | 清华大学 | Flue gas desulfurization by magnesia wet method and recovering process of automatic concentration of product |
| CN206295797U (en) * | 2016-12-07 | 2017-07-04 | 武汉中电楚能环保工程有限公司 | A kind of wet desulphurization device with floating angle steel tower disk |
| CN206843088U (en) * | 2017-06-27 | 2018-01-05 | 河北纽思泰伦环保科技有限公司 | Magnesium desulfurization byproduct refines the processing system of epsom salt technique |
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