CN108636092B - Flue gas desulfurization and denitrification system and method - Google Patents
Flue gas desulfurization and denitrification system and method Download PDFInfo
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- CN108636092B CN108636092B CN201810507712.0A CN201810507712A CN108636092B CN 108636092 B CN108636092 B CN 108636092B CN 201810507712 A CN201810507712 A CN 201810507712A CN 108636092 B CN108636092 B CN 108636092B
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- desulfurization
- flue gas
- denitrification
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- 238000006477 desulfuration reaction Methods 0.000 title claims abstract description 386
- 230000023556 desulfurization Effects 0.000 title claims abstract description 386
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 title claims abstract description 276
- 239000003546 flue gas Substances 0.000 title claims abstract description 276
- 238000000034 method Methods 0.000 title claims abstract description 45
- 239000007921 spray Substances 0.000 claims abstract description 110
- 239000000463 material Substances 0.000 claims abstract description 69
- 238000002156 mixing Methods 0.000 claims abstract description 55
- 239000000428 dust Substances 0.000 claims abstract description 46
- 239000000779 smoke Substances 0.000 claims abstract description 14
- 238000010992 reflux Methods 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims description 162
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 claims description 48
- 239000000920 calcium hydroxide Substances 0.000 claims description 45
- 235000011116 calcium hydroxide Nutrition 0.000 claims description 45
- 229910001861 calcium hydroxide Inorganic materials 0.000 claims description 45
- 239000007800 oxidant agent Substances 0.000 claims description 30
- 239000003795 chemical substances by application Substances 0.000 claims description 28
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 28
- 239000000839 emulsion Substances 0.000 claims description 27
- 230000003009 desulfurizing effect Effects 0.000 claims description 26
- 238000003756 stirring Methods 0.000 claims description 26
- 239000000843 powder Substances 0.000 claims description 23
- 238000009792 diffusion process Methods 0.000 claims description 20
- 230000008569 process Effects 0.000 claims description 20
- 238000007254 oxidation reaction Methods 0.000 claims description 19
- 230000003647 oxidation Effects 0.000 claims description 17
- 238000003860 storage Methods 0.000 claims description 15
- 229910000831 Steel Inorganic materials 0.000 claims description 14
- 239000010959 steel Substances 0.000 claims description 14
- 238000002360 preparation method Methods 0.000 claims description 13
- 239000002002 slurry Substances 0.000 claims description 13
- 238000007789 sealing Methods 0.000 claims description 11
- 238000005243 fluidization Methods 0.000 claims description 10
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- 238000005507 spraying Methods 0.000 claims description 8
- 230000003068 static effect Effects 0.000 claims description 8
- 238000009736 wetting Methods 0.000 claims description 8
- 230000004913 activation Effects 0.000 claims description 5
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 13
- 239000011593 sulfur Substances 0.000 abstract description 13
- 229910052717 sulfur Inorganic materials 0.000 abstract description 13
- 229910002651 NO3 Inorganic materials 0.000 abstract description 12
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 abstract description 12
- 239000002956 ash Substances 0.000 description 48
- TXKMVPPZCYKFAC-UHFFFAOYSA-N disulfur monoxide Inorganic materials O=S=S TXKMVPPZCYKFAC-UHFFFAOYSA-N 0.000 description 27
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical compound S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 27
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 24
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 18
- 230000001590 oxidative effect Effects 0.000 description 18
- 239000000292 calcium oxide Substances 0.000 description 13
- 235000012255 calcium oxide Nutrition 0.000 description 13
- 239000002245 particle Substances 0.000 description 11
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 11
- UKLNMMHNWFDKNT-UHFFFAOYSA-M sodium chlorite Chemical compound [Na+].[O-]Cl=O UKLNMMHNWFDKNT-UHFFFAOYSA-M 0.000 description 10
- 229960002218 sodium chlorite Drugs 0.000 description 10
- 239000011575 calcium Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- 230000001105 regulatory effect Effects 0.000 description 9
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 7
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 6
- JGIATAMCQXIDNZ-UHFFFAOYSA-N calcium sulfide Chemical compound [Ca]=S JGIATAMCQXIDNZ-UHFFFAOYSA-N 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 4
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 230000007613 environmental effect Effects 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 235000011121 sodium hydroxide Nutrition 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- 230000003213 activating effect Effects 0.000 description 3
- 239000003513 alkali Substances 0.000 description 3
- 230000000903 blocking effect Effects 0.000 description 3
- 239000004744 fabric Substances 0.000 description 3
- 239000012286 potassium permanganate Substances 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 229910052815 sulfur oxide Inorganic materials 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 2
- QXIKMJLSPJFYOI-UHFFFAOYSA-L calcium;dichlorite Chemical compound [Ca+2].[O-]Cl=O.[O-]Cl=O QXIKMJLSPJFYOI-UHFFFAOYSA-L 0.000 description 2
- 238000010531 catalytic reduction reaction Methods 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 238000005536 corrosion prevention Methods 0.000 description 2
- 238000007865 diluting Methods 0.000 description 2
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 235000017557 sodium bicarbonate Nutrition 0.000 description 2
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 2
- 229910000029 sodium carbonate Inorganic materials 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 2
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 239000004155 Chlorine dioxide Substances 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002146 bilateral effect Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 235000019398 chlorine dioxide Nutrition 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
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- 230000008021 deposition Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 210000003746 feather Anatomy 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 231100000086 high toxicity Toxicity 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 230000002087 whitening effect Effects 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
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/80—Semi-solid phase processes, i.e. by using slurries
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/02—Particle separators, e.g. dust precipitators, having hollow filters made of flexible material
-
- 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
- B01D53/60—Simultaneously removing sulfur oxides and nitrogen oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/40—Alkaline earth metal or magnesium compounds
- B01D2251/404—Alkaline earth metal or magnesium compounds of calcium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- 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
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Treating Waste Gases (AREA)
Abstract
The invention discloses a flue gas desulfurization and denitrification system and a flue gas desulfurization and denitrification method, and belongs to the technical field of flue gas treatment. The system comprises a pre-dust collector, a rotary spray desulfurization and denitrification system, an induced draft fan and a chimney which are sequentially arranged, wherein a circulating fluidized bed desulfurization system is arranged between the rotary spray desulfurization and denitrification system and the induced draft fan; a flue gas mixing axial adjusting baffle door is arranged between the rotary spray desulfurization and denitrification system and the circulating fluidized bed desulfurization system; a flue for purifying smoke reflux is arranged between the air outlet of the induced draft fan and the smoke mixing axial adjusting baffle door; still include booster conveying fan, material delivery pump I and material delivery pump II. The invention combines the rotary spray desulfurization and denitration system with the circulating fluidized bed desulfurization system, realizes the step desulfurization and denitration of the flue gas, and has high desulfurization and denitration efficiency; the invention can be applied to desulfurization and denitration treatment of flue gas with higher sulfur content and nitrate content due to the adoption of step desulfurization and denitration, and has wide application range.
Description
Technical Field
The invention belongs to the technical field of flue gas treatment, and particularly relates to a flue gas desulfurization and denitrification system and method.
Background
With the rapid development of Chinese economy, the topic of environmental protection is continuously reflected in the eye curtain, the smoke treatment belongs to a great direction in the field of environmental protection, and more importance is placed on the smoke treatment, and in recent years, the exhaust emission index becomes more severe. Government report 2018 indicated SO 2 The NOx emission amount is reduced by 3% compared with 2017, and PM2.5 in important areas is continuously reduced. Under the guidance of a series of policies, most coal-fired power plants are provided with denitration, desulfurization and dust removal devices, and the future promotion of bulk coal boilers and the flue gas treatment of non-electric industries are important tasks for atmospheric treatment.
The flue gas treatment process has more technical routes, and various new processes and new technologies are endless. The flue gas desulfurization technology mainly comprises limestone-gypsum desulfurization, ammonia desulfurization, double-alkali desulfurization, seawater desulfurization and other wet desulfurization processes, rotary spray desulfurization (SDA-FGD), circulating fluidized bed semi-dry desulfurization (CFB-FGD), semi-dry desulfurization processes such as NID and LIFIC, and dry desulfurization processes such as electron beam irradiation. The conventional flue gas denitration technology comprises two denitration technologies, namely SCR (selective catalytic reduction) and SNCR (non-selective catalytic reduction). In recent years, the technology of denitration by an oxidation method is gradually growing, and is widely focused by enterprises and scientific research institutions, and the main oxidants adopted in the denitration technology by the oxidation method are forced oxidants such as ozone, hydrogen peroxide, sodium chlorite, potassium permanganate and the like.
Wet desulfurization is most widely applied in China, and has the advantages of high desulfurization efficiency (98% -99.96%), low calcium-sulfur ratio, mature process and the like. However, along with large-scale industrial application, the method also has the defects of larger water consumption, high power consumption for factories, large occupied area, high investment and operation cost and the need of anti-corrosion treatment for auxiliary matched flue chimneys. In addition, environmental protection policies such as zero emission of desulfurization wastewater, whitening of wet chimney and the like are continuously exported all over the field in 2015-2018, which increases more environmental protection pressure and investment burden for wet desulfurization users. Compared with wet desulfurization, semi-dry desulfurization has the advantages of simple process system, low water consumption, high exhaust gas temperature, low station service, small occupied area, investment saving and the like, and simultaneously, has no problems of waste water emission and tail gas smoke plume. But the single semi-dry desulfurization efficiency is lower, generally lower than 98%, the calcium-sulfur ratio is high, generally between 1.2 and 2.0, and only a small amount of inlet flue gas SO is provided under the limit threshold of ultra-low emission 2 Low (typically below 2000 mg/Nm) 3 ) Is applicable to the occasions, and greatly limits the popularization and application of semi-dry desulfurization.
After 2012, SCR and SNCR flue gas denitration technologies, such as spring bamboo shoots after rain, are widely popularized and applied in China. SCR denitration efficiency is high, the process is mature and reliable, but the catalyst is sensitive to a denitration temperature window, and the catalyst is required to have higher denitration efficiency at 300-420 ℃. Meanwhile, the catalyst body is easy to be abraded by fly ash, and the active potential is easy to carry out complexation reaction with alkali metal to cause poisoning failure. The SNCR denitration system is simple, but has low efficiency, and is mostly used for the condition of low NOx content, or is matched with SCR denitration as an auxiliary means. The forced oxidation denitration method is similar to SNCR, and the system is simpler. Meanwhile, the oxidation method denitration has the advantages of high efficiency, high reaction rate, short reaction flow and the like, and is extremely suitable for occasions with limited arrangement of denitration sites. The oxidative denitration is expected to be popularized and applied in large scale in the future.
Through searching, chinese patent and application number: 201510348272.5, bulletin day: 2015.10.21A multi-stage internal circulation semi-dry desulfurization and denitrification integrated device is disclosed, which utilizes double alkali lye (Ca (OH) 2 NaOH) as absorbent, by ClO 2 The generator generates chlorine dioxide as a strong oxidant, and the internal circulation reactor is used as a basic system to jointly remove various pollutants such as sulfur dioxide, nitrogen oxides, mercury and the like in the flue gas. The system can effectively remove sulfur dioxide, nitrogen oxides and mercury. But the price of alkali liquor is high, clO 2 And the flue gas is difficult to mix uniformly, and is difficult to adapt to the current flue gas variable working condition (flue gas flow and temperature change).
Also, chinese patent, application number: 201611126853.5, publication date: 2017.03.29A semi-dry desulfurization and denitrification device and desulfurization and denitrification process for high-sulfur-concentration flue gas are disclosed, and the semi-dry desulfurization and denitrification device and the desulfurization and denitrification process are processes for humidifying the flue gas and then passing through a three-stage desulfurization and denitrification tower. The process can effectively remove sulfur dioxide and nitrogen oxides in the flue gas, but has the advantages of more reaction towers and complex process. The system utilizes TiO 2 V (V) 2 O 5 Powder for removing NOx, V in flue gas 2 O 5 The powder has high price and high toxicity, and the dust escaping from the dust remover pollutes the surrounding environment.
Disclosure of Invention
Technical problem to be solved by the invention
Aiming at the problems that the traditional semi-dry flue gas desulfurization and denitrification system and method in the prior art are poor in desulfurization and denitrification effect and difficult to popularize and the like, the invention provides the flue gas desulfurization and denitrification system and method, which are combined with a rotary spray desulfurization and denitrification system and a circulating fluidized bed desulfurization system, the step desulfurization and denitrification of flue gas are realized, the desulfurization and denitrification efficiency is high, and meanwhile, the step desulfurization and denitrification is adopted, so that the flue gas desulfurization and denitrification system of the embodiment can be applied to desulfurization and denitrification treatment of flue gas with high sulfur content and high nitrate content, and the application range is wide.
Technical proposal
In order to solve the problems, the technical scheme provided by the invention is as follows:
the flue gas desulfurization and denitrification system comprises a pre-deduster, a rotary spray desulfurization and denitrification system, a draught fan and a chimney which are sequentially arranged, wherein the rotary spray desulfurization and denitrification system is used for carrying out preliminary desulfurization and denitrification on flue gas, and SO (sulfur oxide) is arranged in the flue gas desulfurization and denitrification system 2 Is partially removed and NOx is oxidized to high-valence NO 2 And N 2 O 5 The method comprises the steps of carrying out a first treatment on the surface of the A circulating fluidized bed desulfurization system is arranged between the rotary spray desulfurization and denitration system and the induced draft fan, most unreacted slaked lime particles in the rotary spray desulfurization and denitration system enter the circulating fluidized bed desulfurization system along with the flue gas, and the circulating fluidized bed desulfurization system is used for deeply desulfurizing and denitrating the flue gas; a flue gas mixing axial adjusting baffle door is arranged between the rotary spray desulfurization and denitrification system and the circulating fluidized bed desulfurization system; the flue for purifying the flue gas reflux is arranged between the air outlet of the induced draft fan and the flue gas mixing axial regulating baffle door, and is used for conveying the purified flue gas into the flue gas mixing axial regulating baffle door and mixing the purified flue gas with the flue gas with slaked lime powder particles from the rotary spray desulfurization and denitrification system, so that the purposes of diluting the flue gas, increasing the flue gas amount and stabilizing the pressure of a circulating fluidized bed layer are achieved.
Further, the method comprises, among other things,
the rotary spray desulfurization and denitrification system comprises a rotary spray desulfurization and denitrification reaction tower and a self-flow type high-level emulsion box, wherein the self-flow type high-level emulsion box is arranged above the top of the rotary spray desulfurization and denitrification reaction tower, and forced oxidized slaked lime emulsion in the self-flow type high-level emulsion box falls into the rotary spray desulfurization and denitrification reaction tower under the action of gravity to participate in oxidation reaction in the rotary spray desulfurization and denitrification reaction tower;
the circulating fluidized bed desulfurization system comprises a circulating fluidized bed desulfurization reaction tower and a cloth bag dust remover, wherein the rotary spray desulfurization and denitrification reaction tower is sequentially communicated with the circulating fluidized bed desulfurization reaction tower and the cloth bag dust remover through a flue, and flue gas enters the circulating fluidized bed desulfurization system and sequentially completes deep desulfurization and denitrification and dust removal through the circulating fluidized bed desulfurization reaction tower and the cloth bag dust remover;
the flue gas mixing axial adjusting baffle door is arranged in a flue between the rotary spray desulfurization and denitrification reaction tower and the circulating fluidized bed desulfurization reaction tower.
Further, the middle part position of the bottom of the rotary spray desulfurization and denitrification reaction tower is provided with two side axial exhaust devices, the two side axial exhaust devices are of T-shaped structures formed by mutually forming 90-degree communicated and fixed two steel pipes, one steel pipe is arranged vertically along the axis of the rotary spray desulfurization and denitrification reaction tower, the other steel pipe is arranged horizontally, flue gas enters from two ends of the vertically arranged steel pipe, and then is discharged from the horizontally arranged steel pipe. The flue gas is axially discharged from the upper air inlet and the lower air inlet of the axial exhaust devices at two sides, so that the influence on the rotating air flow in the rotary spray desulfurization and denitrification reaction tower is avoided, the bias current condition existing in the rotary spray desulfurization and denitrification reaction tower is well solved, the residence time of the flue gas in the rotary spray desulfurization and denitrification reaction tower can be prolonged, and the pre-desulfurization efficiency and the oxidation efficiency of nitrogen oxides are improved.
Further, the system also comprises an alkaline slurry preparation system, wherein the alkaline slurry preparation system comprises a desulfurizing agent storage bin, an oxidizing agent storage tank, a constant-temperature stirring box and a double-screw pump; the desulfurizing agent storage bin and the oxidizing agent storage tank are respectively communicated with the constant temperature stirring box through pipelines, and a process water inlet is formed in the constant temperature stirring box; the desulfurizing agent in the desulfurizing agent warehouse can be calcium oxide, calcium hydroxide, sodium hydroxide, carbide slag, sodium carbonate, sodium bicarbonate and the like; the oxidant in the oxidant storage tank can be hydrogen peroxide, sodium chlorite, potassium permanganate and the like; the constant temperature stirring box is used for stirring and mixing the desulfurizing agent and the oxidizing agent, and the process water inlet is used for introducing process water into the constant temperature stirring box.
The constant temperature stirring box, the double-screw pump and the self-flow type high-level emulsion box are sequentially communicated through pipelines, and the double-screw pump is used for pumping the prepared quick lime emulsion into the self-flow type high-level emulsion box for standby.
Further, the device also comprises a booster conveying fan, a material conveying pump I and a material conveying pump II; the air inlet of the booster conveying fan is communicated with the air outlet of the induced draft fan through a pipeline, the air outlet is respectively communicated with the air inlets of the material conveying pump I and the material conveying pump II through a pipeline, and the booster conveying fan is used for increasing the flow speed of clean flue gas and facilitating the circulation of the clean flue gas; the feed inlet of the material conveying pump I is communicated with the rotary spray desulfurization and denitrification reaction tower through a pipeline; the feed inlet of the material conveying pump II is communicated with the circulating fluidized bed desulfurization reaction tower through a pipeline;
A humidifying diffusion pipe device is arranged at the outlet of the venturi throat part in the circulating fluidized bed desulfurization reaction tower, a material returning interface I and a material returning interface II are arranged on the humidifying diffusion pipe device, and the material returning interface I is communicated with a discharge port of the material conveying pump I through a pipeline; and the material returning interface II is communicated with a discharge port of the material conveying pump II through a pipeline.
The pressurizing and conveying fan conveys a part of clean flue gas sent out by the induced draft fan into the material conveying pump I through a pipeline, and the clean flue gas is mixed with slaked lime powder discharged from the bottom of the rotary spray desulfurization and denitrification reaction tower and then conveyed into the material returning interface I; and the other part is sent into the material conveying pump II through a pipeline, mixed with slaked lime powder discharged from the bottom of the circulating fluidized bed desulfurization reaction tower and then sent into the material returning interface II.
Further, the smoke mixing axial adjusting baffle door comprises a volute, a motor is arranged in the volute, the motor is fixed on the inner wall of the volute through a fixing device, a rotating shaft is fixed on an output shaft of the motor, and a plurality of movable vanes are arranged on the rotating shaft; a plurality of stationary vanes are also fixed on the inner wall of the volute; the movable blades and the stationary blades are alternately arranged.
Further, the method comprises, among other things,
the rotating shaft is also provided with sealing rings which are matched with the static blades one by one;
sealing rings which are matched with the movable vanes one by one are also arranged on the inner wall of the volute;
the sealing rings are respectively matched with the ends of the static blades and the movable blades in a tooth shape.
Further, the circulating fluidized bed desulfurization system further comprises a wedge-type valve returning device, wherein the wedge-type valve returning device comprises a wedge-type valve I, a wedge-type valve II, a fluidization air chamber and a receiving cavity, the receiving cavity is detachably connected to the lower end of the bag-type dust remover, and the wedge-type valve I and the wedge-type valve II are respectively detachably connected to the left side and the right side of the receiving cavity; the fluidization air chamber is arranged at the lower end of the receiving cavity; a guide hood is arranged at the inner bottom of the receiving cavity, and penetrates through the bottom of the receiving cavity and is communicated with the fluidization air chamber;
the wedge valve I is communicated with a circulating ash return pipe, and the circulating ash return pipe is led into the middle part of the circulating fluidized bed desulfurization reaction tower; the wedge valve II is communicated with an outer desulfurization ash discharge pipe.
Further, a circulating ash spouting shrinkage ring is arranged in the circulating fluidized bed desulfurization reaction tower, and the circulating ash spouting shrinkage ring is arranged above a discharge port of the circulating ash return pipe.
A flue gas desulfurization and denitrification method comprises the following steps:
step one, introducing flue gas into a pre-deduster for pre-dedusting;
step two, desulfurization and denitrification in the rotary spray desulfurization and denitrification system:
A. preparing forced oxidation slaked lime milk by using an alkaline slurry preparation system, and supplying the forced oxidation slaked lime milk to a rotary spray desulfurization and denitrification reaction tower;
B. introducing the flue gas subjected to pre-dedusting into a rotary spray desulfurization and denitrification reaction tower to perform preliminary desulfurization and denitrification;
C. the treated flue gas is discharged by the axial exhaust devices at the two sides;
step three, desulfurization and denitration in a circulating fluidized bed desulfurization system:
A. introducing the flue gas treated in the second step into a circulating fluidized bed desulfurization reaction tower, and simultaneously, feeding slaked lime powder at the bottom of the rotary spray desulfurization and denitrification reaction tower into a humidifying diffusion pipe device in the circulating fluidized bed desulfurization reaction tower to be in contact with water drops for wetting and activating;
B. the flue gas contacts with wet slaked lime in a humidifying diffusion pipe device to finish fine desulfurization and denitration;
C. introducing the flue gas from the circulating fluidized bed desulfurization reaction tower into a bag-type dust remover for dust removal to generate clean flue gas; meanwhile, the slaked lime powder at the bottom of the circulating fluidized bed desulfurization reaction tower is sent into the humidifying diffusion pipe device;
D. Circulating ash in the bag-type dust remover is led into the circulating fluidized bed desulfurization reaction tower for secondary use;
step four, sending a part of the clean flue gas into a chimney through a draught fan for emptying; part of the flue gas is introduced into a flue gas mixing axial adjusting baffle door to be mixed with the flue gas subjected to desulfurization and denitrification by the rotary spray desulfurization and denitrification system; and the other part of the lime hydrate powder, the rotary spray desulfurization and denitrification reaction tower and the bottom of the circulating fluidized bed desulfurization reaction tower are sent into the humidifying diffusion pipe device.
Advantageous effects
Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:
(1) The flue gas desulfurization and denitrification system combines the rotary spray desulfurization and denitrification system with the circulating fluidized bed desulfurization system to realize the effect of simultaneously completing desulfurization and denitrification by one set of system; meanwhile, the flue gas is desulfurized and denitrated step by step, and the desulfurization and denitration efficiency is high; the flue gas desulfurization and denitration system can be applied to desulfurization and denitration treatment of flue gas with higher sulfur content and nitrate content due to adoption of stepwise desulfurization and denitration, and has a wide application range;
(2) According to the flue gas desulfurization and denitrification system provided by the invention, the flue gas mixing axial adjusting baffle door is arranged between the rotary spray desulfurization and denitrification system and the circulating fluidized bed desulfurization system, and the flue gas mixing axial adjusting baffle door is matched with the flue and the induced draft fan, so that the purpose of controlling the flow of flue gas is achieved, and the stability of a tower layer in the circulating fluidized bed desulfurization system is further ensured; in addition, the axial adjusting baffle has better adjusting characteristics, and the adjusting linearity is high under the condition of low flue gas flow rate;
(3) According to the flue gas desulfurization and denitrification system provided by the invention, the axial exhaust devices on two sides are arranged at the middle part of the bottom of the rotary spray desulfurization and denitrification reaction tower, so that the flue gas in the rotary spray desulfurization and denitrification reaction tower is ensured to be uniformly and axially exhausted, the swirling strength of the flue gas is not destroyed, the effective residence time of the flue gas is 0.5-0.7s more than that of the traditional lateral exhaust, and the desulfurization efficiency of 70-80% and the oxidation efficiency of nitrogen oxides above 90% can be achieved; meanwhile, the ash deposition at the inlet of the gas outlet part of the rotary spray desulfurization and denitrification reaction tower can be avoided;
(4) The flue gas desulfurization and denitrification system provided by the invention further comprises an alkaline slurry preparation system, and the alkaline slurry preparation system is matched with the self-flowing type high-level emulsion box, so that a forced oxidation slaked lime emulsion reactant can be automatically and uninterruptedly provided for the rotary spray desulfurization and denitrification system, and the flue gas desulfurization and denitrification system is good in adjustability, high in safety and low in cost;
(5) The flue gas desulfurization and denitrification system provided by the invention further comprises a booster conveying fan, a material conveying pump I and a material conveying pump II, and the recycling of the slaked lime powder at the two bottoms is realized through the matching arrangement of the booster conveying fan, the material conveying pump I and the material conveying pump II, the rotary spray desulfurization and denitrification reaction tower, the circulating fluidized bed desulfurization reaction tower and the flue gas mixing axial adjusting baffle door and the induced draft fan, and the utilization rate of the desulfurizing agent and the oxidizing agent is high; meanwhile, the clean flue gas can be utilized to participate in circulation, so that the desulfurization and denitration efficiency is high, and the energy is saved;
(6) According to the flue gas desulfurization and denitrification system provided by the invention, the movable vanes and the static vanes are matched in the flue gas mixing axial adjusting baffle door, so that the flue gas desulfurization and denitrification system is good in adjustability, low in flue gas flowing resistance, more uniform in mixing and better in mixing effect, and the shell is streamline;
(7) According to the flue gas desulfurization and denitrification system provided by the invention, the sealing rings matched with the movable vanes and the static vanes are arranged in the flue gas mixing axial regulating baffle door, and the sealing rings are meshed for sealing, so that the sealing effect is good, and the flue gas leakage can be reduced to the greatest extent;
(8) According to the flue gas desulfurization and denitrification system provided by the invention, the wedge-shaped valve returning device is arranged at the lower end of the bag-type dust remover, so that recycling of circulating ash can be realized, and the utilization rate of a desulfurizing agent and an oxidizing agent is improved; meanwhile, the top surface of the fluidization air chamber is provided with a guide hood, so that the desulfurizing agent collected by the bag-type dust collector can realize directional fluidization, and the possibility of blocking ash in the blanking opening and the ash chamber can be reduced to the greatest extent;
(9) According to the flue gas desulfurization and denitrification system provided by the invention, the slaked lime powder scattered at the bottoms of the rotary spray desulfurization and denitrification reaction tower and the circulating fluidized bed desulfurization reaction tower and the circulating ash returned by the wedge-type valve returning device are contacted with water drops for wetting and activating, so that the slaked lime powder scattered at the bottom of the tower and the circulating ash returned by the wedge-type valve returning device can be more reasonably distributed, and the utilization rate is improved;
(10) According to the flue gas desulfurization and denitrification system provided by the invention, the circulating ash spouting shrinkage ring is arranged in the circulating fluidized bed desulfurization reaction tower, so that the flow area in the circulating fluidized bed desulfurization reaction tower is reduced, the flue gas flow speed is accelerated, and the effect of enhancing the flue gas turbulence is achieved; simultaneously, the flow velocity of the flue gas at two sides of the tower wall above the circulating ash spouted shrinkage ring can be reduced, so that part of desulfurizing agent particles naturally subside at the tower wall above the circulating ash spouted shrinkage ring, and the accelerated flue gas can be secondarily lifted when the particles are deposited at the necking of the circulating ash spouted shrinkage ring, thereby improving the circulating flow rate and the residence time in the circulating fluidized bed desulfurization reaction tower, and further improving the utilization rate of slaked lime;
(11) The flue gas desulfurization and denitrification method provided by the invention can realize the desulfurization and denitrification of the flue gas in a grading way, and the sulfur content is 1500-4500mg/Nm 3 The content of the nitrate is 400-800mg/Nm 3 The flue gas desulfurization and denitration efficiency is high; the material utilization rate is high; and has no smoke in tail gasThe feather type desulfurization and denitrification wastewater discharge-free flue gas system has the advantages of no corrosion prevention, large flue gas treatment amount, water and energy conservation, simple equipment arrangement and the like.
Drawings
FIG. 1, a schematic system diagram of the present invention;
FIG. 2 is a schematic diagram of the basic slurry preparation system;
FIG. 3 is a schematic structural diagram of a rotary spray desulfurization and denitrification system;
FIG. 4 is a schematic structural view of a flue gas mixing axial adjustment baffle door;
fig. 5, an enlarged partial view of the position a in fig. 4;
FIG. 6, a schematic view of a moving and stationary vane arrangement;
FIG. 7 is a schematic diagram of a circulating fluidized bed desulfurization system;
FIG. 8 is a schematic diagram of a humidifying diffuser return;
FIG. 9 is a schematic diagram of a wedge valve return apparatus;
FIG. 10 is a schematic diagram of a wedge valve configuration;
in the accompanying drawings: 1. a pre-deduster; 2. an alkaline slurry preparation system; 3. a rotary spray desulfurization and denitrification system; 4. a baffle door is axially adjusted by flue gas mixing; 5. a circulating fluidized bed desulfurization system; 6. an induced draft fan; 7. a booster and delivery fan; 8. a material conveying pump I; 9. a material conveying pump II; 10. a chimney; 21. a desulfurizing agent storage bin; 22. an oxidant storage tank; 23. constant temperature stirring box; 24. a twin screw pump; 31. rotating the spray desulfurization and denitrification reaction tower; 32. self-flowing high-level emulsion box; 33. axial exhaust devices at two sides; 41. a volute; 42. a motor; 43. a fixing device; 44. a movable blade; 45. a stationary blade; 46. a rotating shaft; 47. a seal ring; 50. a circulating fluidized bed desulfurization reaction tower; 51. circulating ash spouts and contracts the ring; 52. a humidifying diffuser pipe device; 53. a venturi throat; 54. a material returning interface I; 55. a material returning interface II; 56. a bag-type dust collector; 57. a wedge valve return device; 58. a circulating ash return pipe; 59. a desulfurized ash outer tube; 571. wedge valve I; 572. wedge valve II; 573. a fluidization air chamber; 574. a guide hood; 575. a receiving cavity; 5701. a valve body; 5702. an actuator; 5703. and a valve core.
Detailed Description
For a further understanding of the present invention, the present invention will be described in detail with reference to the drawings and examples.
Example 1
As shown in fig. 1, a flue gas desulfurization and denitrification system, including the pre-dust remover 1 that sets gradually, rotatory spraying SOx/NOx control system 3, draught fan 6 and chimney 10, pre-dust remover 1, rotatory spraying SOx/NOx control system 3, draught fan 6 and chimney 10 communicate through the flue in proper order, rotatory spraying SOx/NOx control system 3 is used for preliminary desulfurization, denitration to the flue gas, wherein SO 2 Is partially removed and NOx is oxidized to high-valence NO 2 And N 2 O 5 The method comprises the steps of carrying out a first treatment on the surface of the A circulating fluidized bed desulfurization system 5 is arranged between the rotary spray desulfurization and denitrification system 3 and the induced draft fan 6 and is sequentially communicated through a flue, most unreacted slaked lime powder particles in the rotary spray desulfurization and denitrification system 3 enter the circulating fluidized bed desulfurization system 5 along with flue gas, and the circulating fluidized bed desulfurization system 5 is used for deep desulfurization and denitrification of the flue gas; a flue gas mixing axial adjusting baffle door 4 is arranged between the rotary spray desulfurization and denitrification system 3 and the circulating fluidized bed desulfurization system 5, and the flue gas mixing axial adjusting baffle door 4 is axially arranged in the center of the flue along the flue, so that the local resistance during flue gas mixing is reduced, and the flow rate loss is reduced; a flue for clean flue gas reflux is arranged between the air outlet of the induced draft fan 6 and the flue gas mixing axial regulating baffle door 4, and is used for sending clean flue gas into the flue gas mixing axial regulating baffle door 4 and mixing with the flue gas with slaked lime powder particles from the rotary spray desulfurization and denitrification system 3, so that the flue gas flow is improved, and the stability of the bed layer in the circulating fluidized bed desulfurization system 5 is ensured; the flue gas mixing axial adjusting baffle door 4 can enable the flue gas to be fully mixed, and the subsequent denitration efficiency is improved. The pre-deduster 1 can remove most of dust in the flue gas, reduce the ash discharge frequency of a subsequent system, ensure that the desulfurizing agent and the denitrating agent in the subsequent system have larger circulation rate, and achieve the purpose of improving the utilization rate of the desulfurizing agent and the denitrating agent.
The desulfurization and denitrification system of the embodiment uses the forced oxidation slaked lime milk formed by stirring and mixing the desulfurization agent and the oxidant at constant temperature.
The application method of the flue gas desulfurization and denitrification system in this embodiment, as shown in fig. 1, comprises the following steps:
step one, introducing flue gas into a pre-deduster 1 for pre-dedusting;
step two, introducing the flue gas treated in the step one into a rotary spray desulfurization and denitrification system 3 for preliminary desulfurization and denitrification;
step three, introducing the flue gas treated in the step two into a circulating fluidized bed desulfurization system 5 for deep desulfurization and denitration;
step four, sending a part of clean flue gas generated after the treatment in the step three into a chimney 10 through a draught fan 6 for exhausting; and the other part is introduced into a flue gas mixing axial adjusting baffle door 4, mixed with the flue gas subjected to desulfurization and denitrification by the rotary spray desulfurization and denitrification system 3, and introduced into the circulating fluidized bed desulfurization system 5, so that the purpose of diluting the flue gas treated in the second step is achieved.
In the flue gas desulfurization and denitrification system, the rotary spray desulfurization and denitrification system is combined with the circulating fluidized bed desulfurization system, so that the desulfurization and denitrification effects of one set of system are achieved at the same time; meanwhile, the flue gas is desulfurized and denitrated step by step, and the desulfurization and denitration efficiency is high; the flue gas desulfurization and denitration system can be applied to desulfurization and denitration of flue gas with higher sulfur content and nitrate content due to adoption of step desulfurization and denitration, and has a wide application range.
Example 2
The basic structure of the flue gas desulfurization and denitration system of this embodiment is the same as that of embodiment 1, and the difference and improvement lie in that:
as shown in FIG. 3, the rotary spray desulfurization and denitrification system 3 comprises a rotary spray desulfurization and denitrification reaction tower 31 and a self-flow type high-level emulsion box 32, wherein the self-flow type high-level emulsion box 32 is arranged above the top of the rotary spray desulfurization and denitrification reaction tower 31, and forced oxidation slaked lime milk in the self-flow type high-level emulsion box 32 is arranged under the action of gravityThe self-flow pipe arranged at the bottom of the self-flow high-level emulsion box 32 flows into a high-speed centrifugal atomizer in the rotary spray desulfurization and denitrification reaction tower 31, and participates in oxidation reaction in the rotary spray desulfurization and denitrification reaction tower 31 after atomization; in the embodiment, the self-flow pipe is provided with a regulating valve for controlling the flow of the forced oxidation slaked lime emulsion; atomizing the forced oxidized slaked lime emulsion into mist drops with the diameter of 30-200 mu m by a high-speed centrifugal atomizer, wherein the desulfurizing agent and SO in the flue gas 2 The contact completes preliminary desulfurization, and simultaneously the oxidant in the contact with the NOx oxidizes the NOx into NO with high valence state 2 And N 2 O 5 The oxidation of NOx is completed. In this embodiment, the designed flow rate of the flue gas in the rotary spray desulfurization and denitrification reaction tower 31 is less than or equal to 5m/s, the residence time of the flue gas is more than or equal to 1s, and the temperature of the flue gas after flowing through the rotary spray desulfurization and denitrification reaction tower 31 is 80-110 ℃.
As shown in fig. 7, the circulating fluidized bed desulfurization system 5 includes a circulating fluidized bed desulfurization reaction tower 50 and a bag-type dust remover 56, the rotary spray desulfurization and denitrification reaction tower 31 is sequentially communicated with the circulating fluidized bed desulfurization reaction tower 50 and the bag-type dust remover 56 through a flue, and flue gas enters the circulating fluidized bed desulfurization system 5 and then sequentially completes deep desulfurization and denitrification and dust removal through the circulating fluidized bed desulfurization reaction tower 50 and the bag-type dust remover 56. In this embodiment, the designed flow rate of the flue gas in the circulating fluidized bed desulfurization reaction tower 50 is 5-6m/s, the residence time of the flue gas is 5-7s, and the temperature of the flue gas after flowing through the circulating fluidized bed desulfurization reaction tower 50 is 10-20 ℃ higher than the dew point temperature of the acid.
The flue gas mixing axial adjusting baffle door 4 is arranged in a flue between the rotary spray desulfurization and denitrification reaction tower 31 and the circulating fluidized bed desulfurization reaction tower 50, so that the flue gas flow is improved under the low-load condition, and the spouted flow velocity in the circulating fluidized bed desulfurization reaction tower 50 is further improved, so that the stability of a bed layer in the circulating fluidized bed desulfurization reaction tower 50 is ensured, and the occurrence of bed collapse in the tower is avoided; the flue gas mixing axial adjustment damper door 4 is only used at low loads.
The flue gas desulfurization and denitrification system utilizes the embodiment to treat the flue gas under the rated working conditionThe sulfur content is 3200mg/Nm 3 The content of nitrate is 400mg/Nm 3 Dust concentration of 19mg/Nm 3 Is 405000Nm in flue gas flow 3 The oxidant is sodium chlorite, the desulfurizer is quicklime, the mixing ratio is 1:4.9, the desulfurization efficiency of the rotary spray desulfurization and denitrification reaction tower 31 is 85%, and the SO is discharged 2 The content of the catalyst was 480mg/Nm 3 The denitration efficiency is 97.5%, and the content of NOx escaped from the outlet is 10mg/Nm 3 The desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 95.4%, and SO is discharged 2 The content was 22.1mg/Nm 3 。
By utilizing the flue gas desulfurization and denitrification system of the embodiment, the sulfur content is 4500mg/Nm under the rated working condition 3 The content of nitrate is 800mg/Nm 3 Dust concentration is 16mg/Nm 3 Is 285000Nm in flow rate 3 And/h, wherein the oxidant is sodium chlorite, the desulfurizer is quicklime, the mixing ratio is 1:6.7, the desulfurization efficiency of the rotary spray desulfurization and denitrification reaction tower 31 is 84%, and SO is discharged from the rotary spray desulfurization and denitrification reaction tower 2 The content is 720mg/Nm 3 The denitration efficiency is 95.8%, and the content of NOx escaped from the outlet is 33.6mg/Nm 3 The desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 96.3%, and SO is discharged 2 The content was 26.6mg/Nm 3 。
Example 3
As shown in fig. 3, the basic structure of the flue gas desulfurization and denitrification system of the present embodiment is the same as that of embodiment 2, and is different from and improved in that, further, two side axial exhaust devices 33 are disposed at the middle position of the bottom of the rotary spray desulfurization and denitrification reaction tower 31, the two side axial exhaust devices 33 are in a T-shaped structure formed by mutually forming 90 ° communication and fixing two steel pipes, one steel pipe is vertically disposed along the axis of the rotary spray desulfurization and denitrification reaction tower 31, the other steel pipe is horizontally disposed, flue gas enters from two ends of the vertically disposed steel pipe, and then is discharged from the horizontally disposed steel pipe; the flue gas is axially discharged from the upper air inlet and the lower air inlet of the axial exhaust devices 33 at the two sides, so that the influence on the rotating air flow in the rotating spray desulfurization and denitrification reaction tower 31 is avoided, the bias current condition existing in the rotating spray desulfurization and denitrification reaction tower 31 is well solved, the residence time of the flue gas in the rotating spray desulfurization and denitrification reaction tower 31 can be prolonged, and the pre-desulfurization efficiency and the oxidation efficiency of nitrogen oxides are improved. In the embodiment, two ends of the vertical steel pipe extend out of the horizontal steel pipe by 200-300mm respectively, and the design flow rate of the upper port and the lower port of the vertical steel pipe is 7m/s.
Most unreacted slaked lime particles in the rotary spray desulfurization and denitrification reaction tower 31 enter the two-side axial exhaust devices 33 in the middle of the bottom of the rotary spray desulfurization and denitrification reaction tower 31 along with flue gas, enter the flue gas mixing axial regulating baffle door 4 from a communicating flue, and enter the circulating fluidized bed desulfurization reaction tower 50 after being mixed with the returned clean flue gas.
According to the flue gas desulfurization and denitrification system, the rotary spray desulfurization and denitrification reaction tower 31 is smaller, the residence time of flue gas is shorter, and the two-side axial exhaust devices 33 are arranged, so that uniform axial exhaust of flue gas in the rotary spray desulfurization and denitrification reaction tower 31 can be ensured, the swirling strength of the flue gas is not damaged, the effective residence time of the flue gas is 0.5-0.7s more than that of the traditional lateral exhaust, and the 80-85% desulfurization efficiency can be achieved; the adoption of the bilateral axial air outlet can also ensure that the inlet of the air outlet part of the rotary spray desulfurization and denitrification reaction tower is free from dust accumulation.
Example 4
As shown in fig. 2, the basic structure of the flue gas desulfurization and denitration system of the present embodiment is the same as that of embodiment 2 or 3, and is different from and improved in that the flue gas desulfurization and denitration system further comprises an alkaline slurry preparation system 2, wherein the alkaline slurry preparation system 2 comprises a desulfurizing agent storage bin 21, an oxidizing agent storage tank 22, a constant temperature stirring box 23 and a twin screw pump 24; the desulfurizing agent storage bin 21 and the oxidizing agent storage tank 22 are respectively communicated with the constant temperature stirring box 23 through pipelines, and a process water inlet is formed in the constant temperature stirring box 23; the desulfurizing agent in the desulfurizing agent warehouse 21 can be calcium oxide, calcium hydroxide, sodium hydroxide, carbide slag, sodium carbonate, sodium bicarbonate and the like; the oxidant in the oxidant tank 22 may be hydrogen peroxide, sodium chlorite, potassium permanganate, etc.; the constant temperature stirring tank 23 is used for stirring and mixing the desulfurizing agent and the oxidizing agent, and the process water inlet is used for introducing process water into the constant temperature stirring tank 23.
The cooling coil is arranged on the inner wall surface of the constant temperature stirring box 23, the temperature in the constant temperature stirring box can be controlled to be about 30-40 ℃, and meanwhile, the wear-resistant stirring blades are arranged in the constant temperature stirring box; the top of the constant temperature stirring box 23 is also provided with an exhaust port for exhausting, so that the balance and stability of the internal pressure and the external pressure of the constant temperature stirring box 23 are ensured; the mass ratio of the desulfurizing agent to the oxidizing agent is 10:1-4:1, and the solid content of the emulsion is 30% -70%. The constant temperature stirring tank 23, the double screw pump 24 and the self-flowing type high-level emulsion tank 32 are sequentially communicated through pipelines, and the double screw pump 24 is used for pumping the prepared quick lime emulsion into the self-flowing type high-level emulsion tank 32 for standby.
In this example, the oxidant for preparing the forced oxidized slaked lime milk is sodium chlorite, and the desulfurizing agent is quicklime, and the chemical reaction is as follows:
CaO+H 2 O=Ca(OH) 2
the chemical reaction in the rotary spray desulfurization and denitrification reaction tower 31 is as follows:
H 2 O+SO 2 =H 2 SO 3 +Q net
H 2 O+SO 3 =H 2 SO 4 +Q net
Ca(OH) 2 + H 2 SO 3 =CaSO 3 +2H 2 O+Q net
Ca(OH) 2 + H 2 SO 4 =CaSO 4 +2H 2 O+Q net
2NO+NaClO 2 =2NO 2 +NaCl
4NO+3NaClO 2 =2N 2 O 5 +3NaCl
4NO 2 +NaClO 2 =2N 2 O 5 +NaCl
the chemical reaction in the circulating fluidized bed desulfurization reaction tower 50 is as follows:
Ca(OH) 2 + H 2 SO 3 =CaSO 3 +2H 2 O+Q net
2CaSO 3 +O 2 =2CaSO 4
N 2 O 5 +H 2 O=2HNO 3
2HNO 3 +Ca(OH) 2 =Ca(NO 3 ) 2 +2H 2 O
by utilizing the flue gas desulfurization and denitrification system of the embodiment, flue gas with the sulfur content of 4500mg/Nm3, the nitrate content of 252mg/Nm3 and the dust concentration of 37mg/Nm3 is treated under the rated working condition, the flue gas flow is 197000Nm3/h, the oxidant is sodium chlorite, the desulfurizer is quicklime, the mixing ratio is 1:10, the desulfurization efficiency of the rotary spray desulfurization and denitrification reaction tower 31 is 84.5%, and the flue gas is discharged So 2 The content is 697.5mg/Nm3, the denitration efficiency is 92.2%, the content of NOx escaped from the outlet is 19.7mg/Nm3, the desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 96.3%, and the SO is output 2 The content was 25.8mg/Nm3.
By utilizing the flue gas desulfurization and denitrification system of the embodiment, flue gas with the sulfur content of 2050mg/Nm3, the nitrate content of 285mg/Nm3 and the dust concentration of 47mg/Nm3 is treated under the rated working condition, the flue gas flow is 268000Nm3/h, the oxidant is sodium chlorite, the desulfurizer is quicklime, the mixing ratio is 1:4, the desulfurization efficiency of the rotary spray desulfurization and denitrification reaction tower 31 is 78.7%, and the SO is discharged 2 The content is 436.7mg/Nm3, the denitration efficiency is 92.1%, the content of NOx escaped from the outlet is 22.5mg/Nm3, the desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 93.7%, and the SO is output 2 The content was 21.5mg/Nm3.
Example 5
As shown in fig. 1, the flue gas desulfurization and denitration system of the present embodiment has the same basic structure as any one of embodiments 2 to 4, and is different from and improved in that the flue gas desulfurization and denitration system further comprises a booster conveying fan 7, a material conveying pump i 8 and a material conveying pump ii 9; the air inlet of the booster and conveying fan 7 is communicated with the air outlet of the induced draft fan 6 through a pipeline, the air outlet is respectively communicated with the air inlets of the material conveying pump I8 and the material conveying pump II 9 through a pipeline, and the booster and conveying fan 7 is used for increasing the flow rate of clean flue gas and facilitating the circulation of the clean flue gas; the feed inlet of the material conveying pump I8 is communicated with the rotary spray desulfurization and denitrification reaction tower 31 through a pipeline; the feed inlet of the material conveying pump II 9 is communicated with the circulating fluidized bed desulfurization reaction tower 50 through a pipeline;
As shown in FIG. 7, the circulating fluidized bed desulfurization reaction tower 50 is positioned at the outlet of the venturi throat 53The device is provided with a humidifying diffusion pipe device 52, a returning material interface I54 and a returning material interface II 55 are arranged on the humidifying diffusion pipe device 52, and the returning material interface I54 is communicated with a discharge port of the material conveying pump I8 through a pipeline; and the material returning interface II 55 is communicated with a discharge port of the material conveying pump II 9 through a pipeline. In this embodiment, the expansion angle of the outlet of the humidifying and diffusing pipe device 52 is greater than 25 °, the area ratio of the inlet of the humidifying and diffusing pipe device 52 to the area of the venturi throat 53 is 1:2-1:3, and the flow velocity of the throat of the humidifying and diffusing pipe device 52 is 10-15m/s greater than the flow velocity of the venturi throat 53; as shown in FIG. 8, the return ports I54 and II 55 are arranged in tangential circles with the humidifying and diffusing pipe device 52, and the tangential circle diameter is 300-500 mm, SO that the jet flow opposite impact resistance is reduced, and the desulfurizing agent, water drops and SO are reinforced 2 Is a mixture of (a) and (b).
The pressurizing and conveying fan 7 sends a part of clean flue gas sent out by the induced draft fan 6 to the material conveying pump I8 through a pipeline, and the clean flue gas is mixed with slaked lime powder discharged from the bottom of the rotary spray desulfurization and denitrification reaction tower 31 and then sent to the material returning interface I54; the other part is sent into the material conveying pump II 9 through a pipeline, and is mixed with slaked lime powder discharged from the bottom of the circulating fluidized bed desulfurization reaction tower 50 and then sent into the material returning interface II 55. The two portions of the slaked lime particles contact a portion of the water droplets within the humidifying diffuser tube means 52 to complete the wetting activation.
Example 6
As shown in fig. 4 and 6, a flue gas desulfurization and denitrification system of the present embodiment has a basic structure that is the same as any one of embodiments 1 to 5, and is different from and improved in that the flue gas mixing axial adjustment baffle door 4 includes a volute 41, the volute 41 is streamline, a motor 42 is disposed in the volute 41, the motor 42 is fixed on an inner wall of the volute 41 through a fixing device 43, a rotating shaft 46 is fixed on an output shaft of the motor 42, and a plurality of moving blades 44 are disposed on the rotating shaft 46; a plurality of stationary vanes 45 are also fixed on the inner wall of the volute 41; the blades 44 and the vanes 45 are alternately arranged. The blade fan angle of the movable blade 44 and the stationary blade 45 may be 30 °, 35 °, 40 °, 45 °, and in the present embodiment, as shown in fig. 6, the blade fan angle of the movable blade 44 and the stationary blade 45 is 45 °.
In this embodiment, the designed flow rate of the flue gas in the flue gas mixing axial adjustment baffle door 4 is 10-15m/s, the thicknesses of the blades of the movable blade 44 and the static blade 45 are 12mm, and the axial distance between the movable blade 44 and the adjacent static blade 45 is 50 wires.
Example 7
As shown in fig. 5, the basic structure of the flue gas desulfurization and denitrification system of this embodiment is the same as that of embodiment 6, and the difference and improvement are that, in this,
The rotating shaft 46 is also provided with sealing rings 47 which are matched with the static blades 45 one by one;
the inner wall of the volute 41 is also provided with sealing rings 47 which are matched with the movable vanes 44 one by one;
the seal ring 47 is engaged with the ends of the stationary blade 45 and the movable blade 44 in a tooth shape, so that the seal effect is good, and the leakage of smoke can be reduced to the maximum extent.
Example 8
As shown in fig. 9, the flue gas desulfurization and denitration system in this embodiment has a basic structure that is different from any one of embodiments 2 to 7 and is improved in that the circulating fluidized bed desulfurization system 5 further includes a wedge-type valve material returning device 57, the wedge-type valve material returning device 57 includes a wedge-type valve i 571, a wedge-type valve ii 572, a fluidized air chamber 573, and a material receiving cavity 575, the material receiving cavity 575 is detachably connected to the lower end of the bag-type dust collector 56, the wedge-type valve i 571 and the wedge-type valve ii 572 are respectively detachably connected to the left and right sides of the material receiving cavity 575, the wedge-type valve i 571 is an adjustable wedge-type valve, and the wedge-type valve ii 572 is a switch-type wedge-type valve; the fluidization air chamber 573 is arranged at the lower end of the material receiving cavity 575; a guiding air cap 574 is arranged at the bottom of the material receiving cavity 575, and the guiding air caps 574 penetrate through the bottom of the material receiving cavity 575 and are communicated with the fluidization air chamber 573.
As shown in fig. 10, the wedge valve i 571 has the same structure as the wedge valve ii 572, and includes a valve body 5701, an actuator 5702, and a valve core 5703; wherein, the valve core 5703 is made of silicon carbide and is conical. In the embodiment, the central section of the cone is an equilateral triangle with one side length of 100-600mm, and the length of the valve core 5703 is 100-600mm; the guide air caps 574 are arranged one by one every 100×100mm, wherein 3/4 of the guide air caps 574 are arranged on one side close to the wedge-shaped valve I571, air outlets face the wedge-shaped valve I571, 1/4 of the guide air caps 574 are arranged on one side close to the wedge-shaped valve II 572, air outlets face the wedge-shaped valve II 572, and the guide air caps 574 are made of silicon carbide; the guiding air cap 574 is arranged to guide ash particles falling from the bag-type dust collector 56 to flow towards the wedge-type valve I571 and the wedge-type valve II 572 respectively, so that the possibility of ash blocking of the material receiving cavity 575 is reduced; according to material balance calculation, about 3/4-7/8 of circulating ash needs to be returned to the circulating fluidized bed desulfurization reaction tower 50 for recycling; in addition, 1/4-1/8 of the ash hopper is required to be discharged periodically, so that the material level of the ash hopper of the dust remover is ensured not to exceed the limit.
The wedge valve I571 is communicated with a circulating ash return pipe 58, the circulating ash return pipe 58 is led into the middle part of the circulating fluidized bed desulfurization reaction tower 50 and is positioned above the humidifying diffusion pipe device 52, and water drops escaping from the humidifying diffusion pipe device 52 are diffused and then contact with circulating ash conveyed by the circulating ash return pipe 58, so that wetting activation of the circulating ash is completed; the wedge valve II 572 is communicated with a desulfurized ash discharge pipe 59 for periodically discharging accumulated ash to prevent blocking the material receiving cavity 575.
The two stages of the slaked lime powder scattered at the bottoms of the rotary spray desulfurization and denitrification reaction tower 31 and the circulating fluidized bed desulfurization reaction tower 50 and the circulating ash returned by the wedge valve returning device 57 are contacted with water drops and are subjected to wetting activation to finish the fine removal of sulfur dioxide, wherein the two stages of wetting activation mainly consider Ca (OH) in the slaked lime powder scattered at the bottoms of the rotary spray desulfurization and denitrification reaction tower 31 and the circulating fluidized bed desulfurization reaction tower 50 2 High content, and can firstly contact with water drops to complete most of desulfurization tasks.
Example 9
As shown in fig. 7, the flue gas desulfurization and denitration system of the present embodiment has a basic structure similar to that of embodiment 8, and is different from and improved in that a circulating ash spouting shrinkage ring 51 is disposed in the circulating fluidized bed desulfurization reaction tower 50, and the circulating ash spouting shrinkage ring 51 is disposed above a discharge port of the circulating ash return pipe 58. The circulating ash spouting shrinkage ring 51 reduces the flow area in the circulating fluidized bed desulfurization reaction tower 50, and the flue gas passing through the circulating ash spouting shrinkage ring 51 can be accelerated, so that the effect of strengthening the turbulent flow of the flue gas is achieved. Meanwhile, the flow velocity of the flue gas at two sides of the tower wall above the circulating ash spouting shrinkage ring 51 can be reduced, so that part of desulfurizing agent particles are naturally settled at the tower wall above the circulating ash spouting shrinkage ring 51, and the particles are deposited to the necking part of the circulating ash spouting shrinkage ring 51 and can be lifted up by accelerated flue gas for the second time, thereby improving the circulating flow rate and residence time in the circulating fluidized bed desulfurization reaction tower, and further improving the utilization rate of slaked lime.
In this embodiment, the circulating ash spouting shrinkage ring 51 is disposed at a position 500mm above the discharge port of the circulating ash return pipe 58, where an angle of at least 145 ° is formed between the upper edge of the circulating ash spouting shrinkage ring 51 and the tower body of the circulating fluidized bed desulfurization reaction tower 50, so as to ensure that the angle is greater than the ash repose angle, and an angle of 30 ° is formed between the lower edge of the circulating ash spouting shrinkage ring and the tower body of the circulating fluidized bed desulfurization reaction tower 50.
Example 10
A flue gas desulfurization and denitrification method, which uses a flue gas desulfurization and denitrification system of embodiment 8, as shown in figure 1, comprises the following steps: a flue gas desulfurization and denitrification method comprises the following steps:
step one, introducing flue gas into a pre-deduster 1 for pre-dedusting;
step two, desulfurization and denitrification in the rotary spray desulfurization and denitrification system 3 system:
A. preparing forced oxidized slaked lime milk by using an alkaline slurry preparation system 2, and supplying the forced oxidized slaked lime milk to a rotary spray desulfurization and denitrification reaction tower 31;
B. introducing the flue gas subjected to pre-dedusting into a rotary spray desulfurization and denitrification reaction tower 31 for preliminary desulfurization and denitrification;
C. the treated flue gas is discharged by the axial exhaust devices 33 on the two sides;
step three, desulfurization and denitration in the circulating fluidized bed desulfurization system 5:
A. introducing the flue gas treated in the second step into a circulating fluidized bed desulfurization reaction tower 50, and simultaneously, introducing slaked lime powder at the bottom of the rotary spray desulfurization and denitrification reaction tower 31 into a humidifying diffusion pipe device 52 in the circulating fluidized bed desulfurization reaction tower 50 to contact with water drops for wetting and activating;
B. The flue gas contacts with wet slaked lime in the humidifying diffusion pipe device 52 to finish fine desulfurization and denitration;
C. introducing the flue gas from the circulating fluidized bed desulfurization reaction tower 50 into a bag-type dust remover 56 for dust removal to generate clean flue gas; meanwhile, the slaked lime powder at the bottom of the circulating fluidized bed desulfurization reaction tower 50 is sent into the humidifying diffusion pipe device 52;
D. and introducing the circulating ash in the bag-type dust remover 56 into the circulating fluidized bed desulfurization reaction tower 50 for secondary use.
Step four, sending a part of the clean flue gas into a chimney 10 through a draught fan 6 for emptying; part of the flue gas is introduced into a flue gas mixing axial adjusting baffle door 4 to be mixed with the flue gas subjected to desulfurization and denitrification by the rotary spray desulfurization and denitrification system 3; and the lime hydrate powder which is still part of the bottom of the rotary spray desulfurization and denitrification reaction tower 31 and the bottom of the circulating fluidized bed desulfurization reaction tower 50 is sent into the humidifying diffusion pipe device 52.
The specific case of treating the flue gas by using the flue gas desulfurization and denitration system of embodiment 8 and combining the flue gas desulfurization and denitration method of this embodiment is as follows:
case one, sulfur content of 3200mg/Nm 3 The content of nitrate is 400mg/Nm 3 Is characterized by comprising the following steps:
inlet flue gas conditions:
Flue gas temperature: 130 DEG C
Flue gas flow (standard state): 465000Nm 3 And/h, fluctuation range of flue gas flow: 200000-465000Nm 3 /h
SO 2 Concentration: 3200mg/Nm 3
NOx concentration: 400mg/Nm 3
Dust concentration: 20mg/Nm 3
The oxidant used in this example is sodium chlorite and the desulphurizer is quicklime.
Firstly, preparing calcium chlorite and quicklime into forced oxidation slaked lime emulsion according to the proportion of 1:4.9, wherein the mass fraction of the solid of the emulsion is 60%, and the mass ratio of the oxidant to the slaked lime is 1:6.5.
Under the rated working condition, the designed flow rate of the flue gas in the rotary spray desulfurization and denitrification reaction tower 31 is 5m/s, the residence time is 1s, the desulfurization efficiency is 81%, and SO is discharged 2 The content is 608mg/Nm 3 The denitration efficiency is 97%, and the content of NOx escaping from the outlet is 12mg/Nm 3 The flue gas temperature is 107 ℃, and the resistance of the rotary spray desulfurization and denitrification reaction tower 31 is 170Pa. After leaving the rotary spray desulfurization and denitrification reaction tower 31, the flue gas flows through the flue gas mixing axial adjustment baffle door 4, the flue gas mixing axial adjustment baffle door 4 is in a closed state, and the pressure loss of the flue gas mixing axial adjustment baffle door 4 is 50Pa. The flue gas enters a circulating fluidized bed desulfurization reaction tower 50, the desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 95%, and SO is discharged 2 The content was 30.4mg/Nm 3 The flue gas resistance of the circulating fluidized bed desulfurization reaction tower 50 is 1500Pa, the temperature of the outlet flue gas is 68 ℃, and the water spraying amount is 12t/h. The calcium-sulfur ratio of the integral flue gas desulfurization and denitrification system is 1.65:1. The pressure drop from the outlet of the circulating fluidized bed desulfurization reaction tower 50 to the bag-type dust collector 56 is considered according to 1200Pa, the system flue resistance is considered according to 500Pa, the resistance of the integral flue gas desulfurization and denitrification system is about 3420Pa, and the water consumption of the system is about 17.5t/h.
Under the condition of 75%, the flow rate of the flue gas of the rotary spray desulfurization and denitrification reaction tower 31 is 3.75m/s, the residence time is 1.33s, the desulfurization efficiency is 83%, and the SO is discharged 2 The content was 544mg/Nm 3 The denitration efficiency is 97.2 percent, and the content of NOx escaped from the outlet is 11.2mg/Nm 3 The flue gas temperature is 105 ℃, and the resistance of the rotary spray desulfurization and denitrification reaction tower 31 is 100Pa. After leaving the rotary spray desulfurization and denitrification reaction tower 31, the flue gas flows through the flue gas mixing axial adjusting baffle door 4, the flue gas mixing axial adjusting baffle door 4 is at 35 percent of opening, and the reflux flue gas is 90000Nm 3 And/h, the pressure loss of the smoke mixing axial regulating baffle door 4 is 70Pa. The flue gas enters a circulating fluidized bed desulfurization reaction tower 50, the desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 95.6%, and SO is discharged 2 The content was 23.9mg/Nm 3 The flue gas resistance of the circulating fluidized bed desulfurization reaction tower 50 is 1000Pa,the temperature of the outlet flue gas is 68 ℃, and the water spraying amount is 8t/h. The calcium-sulfur ratio of the integral flue gas desulfurization and denitrification system is 1.5:1. The pressure drop from the outlet of the circulating fluidized bed desulfurization reaction tower 50 to the bag-type dust collector 56 is considered according to 1200Pa, the system flue resistance is considered according to 500Pa, the resistance of the integral flue gas desulfurization and denitrification system is about 2870Pa, and the water consumption of the system is about 13.5t/h.
Under the working condition of 50%, the flow rate of the flue gas of the rotary spray desulfurization and denitrification reaction tower 31 is 2.5m/s, the residence time is 2s, the desulfurization efficiency is 85%, and SO is discharged 2 The content of the catalyst was 480mg/Nm 3 The denitration efficiency is 97.8%, and the content of NOx escaped from the outlet is 8.8mg/Nm 3 The flue gas temperature is 98 ℃, and the resistance of the SDA tower is 45Pa. After leaving the rotary spray desulfurization and denitrification reaction tower 31, the flue gas flows through the flue gas mixing axial adjusting baffle door 4, the flue gas mixing axial adjusting baffle door 4 is at 65% opening, and the reflux flue gas is 180000Nm 3 And/h, the pressure loss of the smoke mixing axial regulating baffle door 4 is 100Pa. The flue gas enters a circulating fluidized bed desulfurization reaction tower 50, the desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 96%, and SO is discharged 2 The content was 19.2mg/Nm 3 The flue gas resistance of the circulating fluidized bed desulfurization reaction tower 50 is 980Pa, the outlet flue gas temperature is 67 ℃, and the water spraying amount is 4t/h. The calcium-sulfur ratio of the integral flue gas desulfurization and denitrification system is 1.38:1. The pressure drop from the outlet of the circulating fluidized bed desulfurization reaction tower 50 to the bag-type dust collector 56 is considered according to 1200Pa, the resistance of the system flue is considered according to 450Pa, the resistance of the integral flue gas desulfurization and denitrification system is about 2775Pa, and the water consumption of the system is about 8.75t/h.
Case two, sulfur content of 4500mg/Nm 3 The content of nitrate is 800mg/Nm 3 Is characterized by comprising the following steps:
inlet flue gas conditions:
flue gas temperature: 135 DEG C
Flue gas flow (standard state): 305500 Nm 3 /h
SO 2 Concentration: 4500mg/Nm 3
NOx concentration: 800mg/Nm 3
Dust concentration: 17mg/Nm 3
The system is designed with sodium chlorite as oxidant and calcium lime as desulfurizing agent.
Firstly, preparing calcium chlorite and quicklime into forced slaked lime emulsion according to the proportion of 1:6.7, wherein the mass fraction of the solid of the emulsion is 60%, and the mass ratio of the oxidant to the slaked lime is 1:5.2.
Under the rated working condition, the designed flow rate of the flue gas in the rotary spray desulfurization and denitrification reaction tower 31 is 3m/s, the residence time is 2s, the desulfurization efficiency is 83%, and the SO is discharged 2 The content is 765mg/Nm 3 The denitration efficiency is 94%, and the escape amount of the NOx in the low-valence state is 48mg/Nm 3 The flue gas temperature is 110 ℃, and the resistance of the rotary spray desulfurization and denitrification reaction tower 31 is 150Pa. After leaving the rotary spray desulfurization and denitrification reaction tower 31, the flue gas flows through the flue gas mixing axial adjustment baffle door 4, the flue gas mixing axial adjustment baffle door 4 is in a closed state, and the pressure loss of the flue gas mixing axial adjustment baffle door 4 is 50Pa. The flue gas enters a circulating fluidized bed desulfurization reaction tower 50, the desulfurization efficiency of the circulating fluidized bed desulfurization reaction tower 50 is 95.9%, and SO is discharged 2 The content was 31.4mg/Nm 3 The flue gas resistance of the circulating fluidized bed desulfurization reaction tower 50 is 1700Pa, the temperature of the outlet flue gas is 68 ℃, and the water spraying amount is 7.8t/h. The calcium-sulfur ratio of the integral flue gas desulfurization and denitrification system is 1.97:1. The pressure drop from the outlet of the circulating fluidized bed desulfurization reaction tower 50 to the bag-type dust collector 56 is considered according to 1300Pa, the system flue resistance is considered according to 500Pa, the resistance of the integral flue gas desulfurization and denitrification system is about 3700Pa, and the water consumption of the system is about 11.4t/h.
The flue gas desulfurization and denitrification method of the embodiment can realize the desulfurization and denitrification of the flue gas with the sulfur content of 1500-4500mg/Nm 3 The content of the nitrate is 400-800mg/Nm 3 The flue gas desulfurization and denitration method is applicable to occasions with high sulfur content flue gas, and has high desulfurization and denitration efficiency; the material utilization rate is high; the method has the advantages of no smoke plume of tail gas, no desulfurization and denitrification wastewater discharge, no corrosion prevention of a flue gas system, large flue gas treatment amount, water and energy conservation, simple equipment arrangement and the like.
The invention and its embodiments have been described above by way of illustration and not limitation, and the invention is illustrated in the accompanying drawings and described in the drawings in which the actual structure is not limited thereto. Therefore, if one of ordinary skill in the art is informed by this disclosure, the structural mode and the embodiments similar to the technical scheme are not creatively designed without departing from the gist of the present invention.
Claims (5)
1. The utility model provides a flue gas desulfurization denitration system, includes pre-dust remover (1), rotatory spraying SOx/NOx control system (3), draught fan (6) and chimney (10) that set gradually, its characterized in that: a circulating fluidized bed desulfurization system (5) is arranged between the rotary spray desulfurization and denitrification system (3) and the induced draft fan (6); a flue gas mixing axial adjusting baffle door (4) is arranged between the rotary spray desulfurization and denitrification system (3) and the circulating fluidized bed desulfurization system (5); a flue for purifying smoke reflux is arranged between the air outlet of the induced draft fan (6) and the smoke mixing axial adjusting baffle door (4);
Wherein,
the rotary spray desulfurization and denitrification system (3) comprises a rotary spray desulfurization and denitrification reaction tower (31) and a self-flow type high-level emulsion box (32), wherein the self-flow type high-level emulsion box (32) is arranged above the top of the rotary spray desulfurization and denitrification reaction tower (31);
the circulating fluidized bed desulfurization system (5) comprises a circulating fluidized bed desulfurization reaction tower (50) and a bag-type dust remover (56), and the rotary spray desulfurization and denitration reaction tower (31) is sequentially communicated with the circulating fluidized bed desulfurization reaction tower (50) and the bag-type dust remover (56) through a flue;
the middle part of the bottom of the rotary spray desulfurization and denitrification reaction tower (31) is provided with two side axial exhaust devices (33), and the two side axial exhaust devices (33) are of a T-shaped structure formed by mutually forming 90-degree communicated and fixed two steel pipes;
the device also comprises a booster conveying fan (7), a material conveying pump I (8) and a material conveying pump II (9); the air inlet of the booster conveying fan (7) is communicated with the air outlet of the induced draft fan (6) through a pipeline, and the air outlet is respectively communicated with the air inlets of the material conveying pump I (8) and the material conveying pump II (9) through a pipeline; the feed inlet of the material conveying pump I (8) is communicated with the rotary spray desulfurization and denitrification reaction tower (31) through a pipeline; the feed inlet of the material conveying pump II (9) is communicated with the circulating fluidized bed desulfurization reaction tower (50) through a pipeline;
A humidifying diffusion pipe device (52) is arranged at the outlet of a venturi throat (53) in the circulating fluidized bed desulfurization reaction tower (50), a material returning interface I (54) and a material returning interface II (55) are arranged on the humidifying diffusion pipe device (52), and the material returning interface I (54) is communicated with a discharge port of the material conveying pump I (8) through a pipeline; the material returning interface II (55) is communicated with a discharge port of the material conveying pump II (9) through a pipeline;
the smoke mixing axial adjusting baffle door (4) comprises a volute (41), a motor (42) is arranged in the volute (41), the motor (42) is fixed on the inner wall of the volute (41) through a fixing device (43), a rotating shaft (46) is fixed on an output shaft of the motor (42), and a plurality of movable blades (44) are arranged on the rotating shaft (46); a plurality of stationary vanes (45) are also fixed on the inner wall of the volute (41); the movable blades (44) and the stationary blades (45) are alternately arranged;
the rotating shaft (46) is also provided with sealing rings (47) which are matched with the static blades (45) one by one;
sealing rings (47) which are matched with the movable blades (44) one by one are also arranged on the inner wall of the volute (41);
The seal ring (47) is engaged with the ends of the stator blade (45) and the movable blade (44) in a tooth shape.
2. The flue gas desulfurization and denitrification system according to claim 1, wherein: the system also comprises an alkaline slurry preparation system (2), wherein the alkaline slurry preparation system (2) comprises a desulfurizing agent storage bin (21), an oxidizing agent storage tank (22), a constant-temperature stirring box (23) and a double-screw pump (24); the desulfurizing agent storage bin (21) and the oxidizing agent storage tank (22) are respectively communicated with the constant temperature stirring box (23) through pipelines, and a process water inlet is formed in the constant temperature stirring box (23);
the constant temperature stirring box (23), the double-screw pump (24) and the self-flowing high-level emulsion box (32) are sequentially communicated through pipelines.
3. A flue gas desulfurization and denitrification system according to claim 1 or 2, wherein: the circulating fluidized bed desulfurization system (5) further comprises a wedge-type valve returning device (57), wherein the wedge-type valve returning device (57) comprises a wedge-type valve I (571), a wedge-type valve II (572), a fluidized air chamber (573) and a receiving cavity (575), the receiving cavity (575) is detachably connected to the lower end of the bag-type dust collector (56), and the wedge-type valve I (571) and the wedge-type valve II (572) are detachably connected to the left side and the right side of the receiving cavity (575) respectively; the fluidization air chamber (573) is arranged at the lower end of the material receiving cavity (575); a guide hood (574) is arranged at the inner bottom of the receiving cavity (575), and the guide hood (574) penetrates through the bottom of the receiving cavity (575) and is communicated with the fluidization air chamber (573);
The wedge valve I (571) is communicated with a circulating ash return pipe (58), and the circulating ash return pipe (58) is led into the middle part of the circulating fluidized bed desulfurization reaction tower (50); the wedge valve II (572) is communicated with a desulfurization ash discharge pipe (59).
4. A flue gas desulfurization and denitrification system according to claim 3, wherein: the circulating fluidized bed desulfurization reaction tower (50) is internally provided with a circulating ash spouting shrinkage ring (51), and the circulating ash spouting shrinkage ring (51) is arranged above a discharge port of the circulating ash return pipe (58).
5. The flue gas desulfurization and denitrification method is characterized by comprising the following steps:
step one, introducing flue gas into a pre-deduster (1) for pre-dedusting;
step two, desulfurization and denitration in a rotary spray desulfurization and denitration system (3) system:
A. preparing forced oxidation slaked lime milk by using an alkaline slurry preparation system (2), and supplying the forced oxidation slaked lime milk to a rotary spray desulfurization and denitrification reaction tower (31);
B. introducing the flue gas subjected to pre-dedusting into a rotary spray desulfurization and denitrification reaction tower (31) for preliminary desulfurization and denitrification;
C. the treated flue gas is discharged by two side axial exhaust devices (33);
step three, desulfurization and denitration in the circulating fluidized bed desulfurization system (5):
A. Introducing the flue gas treated in the second step into a circulating fluidized bed desulfurization reaction tower (50), and simultaneously, feeding slaked lime powder at the bottom of the rotary spray desulfurization and denitrification reaction tower (31) into a humidifying diffusion pipe device (52) in the circulating fluidized bed desulfurization reaction tower (50), and carrying out contact wetting activation with water drops;
B. the flue gas contacts with wet slaked lime in a humidifying diffusion pipe device (52) to finish fine desulfurization and denitration;
C. introducing the flue gas from the circulating fluidized bed desulfurization reaction tower (50) into a bag-type dust remover (56) for dust removal to generate clean flue gas; meanwhile, feeding slaked lime powder at the bottom of the circulating fluidized bed desulfurization reaction tower (50) into the humidifying diffusion pipe device (52);
D. circulating ash in the bag-type dust remover (56) is introduced into the circulating fluidized bed desulfurization reaction tower (50) for secondary utilization;
step four, sending a part of the clean flue gas into a chimney (10) through a draught fan (6) for emptying; part of the flue gas is introduced into a flue gas mixing axial adjusting baffle door (4) to be mixed with the flue gas subjected to desulfurization and denitrification by the rotary spray desulfurization and denitrification system (3); and the other part of the lime hydrate powder, which is connected with the bottom of the rotary spray desulfurization and denitrification reaction tower (31) and the bottom of the circulating fluidized bed desulfurization reaction tower (50), is sent into the humidifying diffusion pipe device (52).
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| CN109157956A (en) * | 2018-10-22 | 2019-01-08 | 南京中电环保科技有限公司 | A kind of SDA that absorbent efficiently utilizes and CFB coordinated desulfurization system |
| CN110548387A (en) * | 2019-09-23 | 2019-12-10 | 上海蓝科石化环保科技股份有限公司 | integrated treatment device and process for ion denitration, desulfurization and dust removal by semidry method |
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| CN112495176B (en) * | 2020-11-04 | 2022-11-15 | 江苏垦乐节能环保科技有限公司 | Semi-dry desulfurization synergistic device and implementation method thereof |
| CN115155286A (en) * | 2022-05-31 | 2022-10-11 | 江苏亿金环保科技有限公司 | Low-concentration dry-wet combined desulfurization system |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5345884A (en) * | 1992-11-24 | 1994-09-13 | Stein Industrie | Method of reducing polluting emissions from circulating fluidized bed combustion intallations |
| CN101357298A (en) * | 2007-07-31 | 2009-02-04 | 黄盛珠 | Circulating fluid bed flue gas desulfurization technique and device |
| WO2009026611A1 (en) * | 2007-08-29 | 2009-03-05 | Mario John Chaves Barker | A vacuum cleaner |
| CN101417206A (en) * | 2008-11-12 | 2009-04-29 | 刘昌林 | Spraying desulphurization device |
| CN101695627A (en) * | 2009-10-31 | 2010-04-21 | 福建龙净脱硫脱硝工程有限公司 | Dry-method fume gas purification method and device for synchronous desulfurization and denitrification |
| CN102908889A (en) * | 2012-10-23 | 2013-02-06 | 鞍钢股份有限公司 | Sintering flue gas desulfurization and denitrification system and desulfurization and denitrification method thereof |
| CN205461778U (en) * | 2016-02-18 | 2016-08-17 | 北京博朗生态环境科技股份有限公司 | Semidry method circulating fluidized bed flue gas is SOx/NOx control device simultaneously |
| CN206473999U (en) * | 2017-02-15 | 2017-09-08 | 福建龙净环保股份有限公司 | A kind of dry type desulfurizing denitration dust removal system of regeneration fume from catalytic cracking |
| CN208553730U (en) * | 2018-05-24 | 2019-03-01 | 南京石博环保科技有限公司 | A kind of flue gas desulfurization and denitrification system |
-
2018
- 2018-05-24 CN CN201810507712.0A patent/CN108636092B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5345884A (en) * | 1992-11-24 | 1994-09-13 | Stein Industrie | Method of reducing polluting emissions from circulating fluidized bed combustion intallations |
| CN101357298A (en) * | 2007-07-31 | 2009-02-04 | 黄盛珠 | Circulating fluid bed flue gas desulfurization technique and device |
| WO2009026611A1 (en) * | 2007-08-29 | 2009-03-05 | Mario John Chaves Barker | A vacuum cleaner |
| CN101417206A (en) * | 2008-11-12 | 2009-04-29 | 刘昌林 | Spraying desulphurization device |
| CN101695627A (en) * | 2009-10-31 | 2010-04-21 | 福建龙净脱硫脱硝工程有限公司 | Dry-method fume gas purification method and device for synchronous desulfurization and denitrification |
| CN102908889A (en) * | 2012-10-23 | 2013-02-06 | 鞍钢股份有限公司 | Sintering flue gas desulfurization and denitrification system and desulfurization and denitrification method thereof |
| CN205461778U (en) * | 2016-02-18 | 2016-08-17 | 北京博朗生态环境科技股份有限公司 | Semidry method circulating fluidized bed flue gas is SOx/NOx control device simultaneously |
| CN206473999U (en) * | 2017-02-15 | 2017-09-08 | 福建龙净环保股份有限公司 | A kind of dry type desulfurizing denitration dust removal system of regeneration fume from catalytic cracking |
| CN208553730U (en) * | 2018-05-24 | 2019-03-01 | 南京石博环保科技有限公司 | A kind of flue gas desulfurization and denitrification system |
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