CN106166437A - A kind of cement kiln flue gas desulphurization system and method - Google Patents

A kind of cement kiln flue gas desulphurization system and method Download PDF

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CN106166437A
CN106166437A CN201610581553.XA CN201610581553A CN106166437A CN 106166437 A CN106166437 A CN 106166437A CN 201610581553 A CN201610581553 A CN 201610581553A CN 106166437 A CN106166437 A CN 106166437A
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ammonia
cement kiln
flue gas
spray
ejecting gun
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CN106166437B (en
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巫世财
刘栋梁
吴德利
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NANJING C-HOPE ENVIRONMENTAL SCIENCE AND TECHNOLOGY Co Ltd
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NANJING C-HOPE ENVIRONMENTAL SCIENCE AND TECHNOLOGY Co Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77—Liquid phase processes
    • B01D53/78—Liquid phase processes with gas-liquid contact
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/48—Sulfur compounds
    • B01D53/50—Sulfur oxides
    • B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
    • B01D53/502—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific solution or suspension
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/48—Sulfur compounds
    • B01D53/50—Sulfur oxides
    • B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
    • B01D53/504—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound characterised by a specific device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2062—Ammonia
    • 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
    • B01D2258/0233—Other waste gases from cement factories
    • 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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  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Treating Waste Gases (AREA)

Abstract

A kind of cement kiln flue gas desulphurization system and method, including tank used for storing ammonia, delivery pump, ejecting gun, cement decomposing furnace, cement kiln precalcining system and automatic control system, cement kiln precalcining system includes multistage preheater, described tank used for storing ammonia is connected with ejecting gun by delivery pump, and the spray site of ejecting gun is positioned at the exit of second level preheater windspout barrel.The method of described desulfurization, including one, the ammonia of configuration 15% 25%；Two, SO is detected in real time2Concentration, according to SO in flue gas2Concentration, calculates, adjusts the emitted dose of ammonia by automatic control system；Three, according to the ammonia water spray amount calculated in step 2, being injected in cement kiln precalcining system by ammonia after delivery pump supercharging after injecting jet rifle, injection is positioned at the exit of cement kiln second level preheater windspout barrel.Inventive desulfurization efficiency is up to more than 95%, and desulfuration efficiency is high, and ratio of ammonia-sulfur is 2～2.5, and operating cost is low.

Description

A kind of cement kiln flue gas desulphurization system and method
Technical field:
The invention belongs to cement kiln cigarette technical field of desulfurization, be specifically related to a kind of utilize ammonia as the cement of desulfurizing agent De-suphur of kiln fume system and method.
Background technology
The coal-fired utility production processes such as thermal power plant, steel mill, Industrial Boiler, cement plant can produce substantial amounts of sulfur dioxide, Sulfur dioxide can be oxidized to sulfuric acid mist or sulfate aerosol in an atmosphere, and it is the important predecessor causing acid rain.Thermal power plant, The most supporting desulfurization equipment that has such as steel mill, Industrial Boiler, the sulfur major part meeting that cement plant produces in process of production due to it Oxidized calcium absorption, so sulfur dioxide emissioning concentration is the highest, major part production line can meet standard-required.But some plant area Sulfur content of raw material is too high, and the concentration of emission of sulfur dioxide is the highest, 200～2000mg/m3?.Country is to environmental protection in recent years Requirement increasingly stricter, according to up-to-date cement production enterprise exhaust emission standard " cement industry atmosphere pollutants emission standards " (GB4915-2013) regulation in, cement kiln sulfur dioxide maximal emission is less than 200mg/m3, key area is less than 100mg/m3.Therefore, the enterprise exceeded standard for sulfur dioxide, in the urgent need to the cement kiln desulphurization system of a set of maturation.
Sulfur in quality coal in cement kiln systems is to be brought into by raw material and fuel: 1), present in raw material sulfate at pre-heating system It is generally do not form SO2Gas, the most all can enter kiln system.A portion sulfate can thermal zone in kiln divide Solve, the SO of generation2Gas moves to kiln tail with kiln gas, when arriving minimum two-stage preheater equitemperature lower region, is condensate in On the raw material that temperature is relatively low, and enter in kiln with the heavy collection of raw material, form a blood circulation between preheater and kiln, Undecomposed sulfate then can leave kiln system along with grog.The sulfur existed otherwise in raw material is (mainly with sulfide Form exists), then can be at 300～600 DEG C of oxidized generation SO2Gas, occurs mainly in the second level of five (four) level preheaters The third level cyclone cylinder of cyclone cylinder or six grades of preheaters.2), in precalciner system, fuel is fed by kiln hood and dore furnace Enter.The SO that dore furnace fuel combustion generates2A large amount of activity CaO that the stove that can be decomposed exists absorb, the CaSO of generation4With material warp Lowermost level cyclone cylinder is entered in kiln by kiln tail smoke-box.The SO that the fuel of kiln hood feeding produces2Gas can be with sulfate height in kiln The SO produced is decomposed in temperate zone2The course that gas experience is similar.
The SO that sulfur oxidation in raw material produces2Can be partially absorbed when by higher level's cyclone cylinder, remaining is then with waste gas one Road is discharged from preheater.If waste gas is used for drying material, then SO2Raw material grinding mill is absorbed further.In temperature less than 600 In the case of DEG C, CaCO3To SO2Absorption efficiency CaO to be far below.CaCO in two-stage preheater above3Resolution ratio is extremely low, and Only having a small amount of CaO by flue gas from high-temperature part band up, therefore absorption efficiency is the lowest.Add now humidity relatively low and discharge The front time of staying is shorter, SO2Concentration of emission may be the highest.If there is organic sulfur compound, its oxidation behavior connects with troilite Closely.
Conventional desulfurization technique currently mainly is divided into dry desulfurization, semi-dry desulphurization and wet desulphurization three class.Dry desulfurization Technique includes reactant insufflation, hot raw material insufflation etc., and semi-dry desulphurization is mainly spray dry desulfurization method, wet desulphurization bag Include the sulfur removal technologies such as the ammonia process of desulfurization, double alkali method desulfurizing, limestone-gypsum method.
Dry method and semi-dry desulfurizing process operating cost are high, and desulfuration efficiency is low, and being applied to cement kiln has the biggest restriction. Dual alkali, lime stone-gypsum method are widely used in the industries such as thermal power plant, steel mill, Industrial Boiler, and desulfuration efficiency is high, but the type desulfurization Technique is once invested relatively big, and operating cost is high, overweight for ordinary cement business burden, the most inapplicable.
Cement producing line has the features such as exhaust gas volumn is big, material multi preheating, gas residence time length, in addition in kiln system The cyclical effect of the most peculiar sulfur so that conventional sulfur removal technology is not particularly suited for cement kiln.Therefore, a kind of cement of exploitation is needed badly The special low cost of kiln, high efficiency sulfur removal technology.
Summary of the invention
It is an object of the invention to provide and a kind of utilize ammonia as the cement kiln flue gas desulphurization system of desulfurizing agent and side Method, solves the technical problem that in prior art, cement kiln desulfuration efficiency is low.
In order to solve this technical problem, the present invention adopts the following technical scheme that
A kind of cement kiln flue gas desulphurization system, including tank used for storing ammonia, delivery pump, ejecting gun, cement decomposing furnace, cement kiln Precalcining system and automatic control system, cement kiln precalcining system includes multistage preheater, and described tank used for storing ammonia is by conveying Pump connects with ejecting gun, and the spray site of ejecting gun is positioned at the exit of second level preheater windspout barrel, described ejecting gun at least ?；Pneumatic control valve it is provided with, in cement kiln precalcining system on pipeline between the port of export and the ejecting gun of described delivery pump It is provided with detection device, is electrically connected between detection device and pneumatic control valve and automatic control system.
Improve further, also include that return duct, one end of described return duct connect with the port of export of ammonium hydroxide delivery pump, another End connects with tank used for storing ammonia, and return duct is provided with reflux inlet and ammonia discharge pressure table.By regulation reflux inlet regulation backflow Amount controls ammonia discharge pressure, the Pressure gauge display ammonia discharge pressure value on return duct.
Improving further, described delivery pump is two, and is arranged in parallel, is provided with system between delivery pump and tank used for storing ammonia Main valve.Two delivery pumps are used alternatingly, and extend its service life, and when one of them damages, another one is opened, it is ensured that Desulphurization system can be properly functioning.
Improve further, the pipeline between the port of export and the ejecting gun of described delivery pump is provided with needle-valve, Electromagnetic Flow Meter, pressure switch, ammonia leak detector and ammonia endless tube；Wherein, pneumatic control valve is arranged in parallel with needle-valve, and ammonia enters ammonia Each ammonia water spray rifle it is evenly distributed to after endless tube.Needle-valve is maintenance bypass valve, it addition, when pneumatic control valve is fully open Shi Liuliang still cannot meet requirement can suitably supplement flow by needle-valve.The flow monitoring of ammonia is detected by electromagnetic flowmeter. The pressure of ammonia, shutdown system of reporting to the police when hypertonia in pressure switch detection whole system, ammonia leak detector detects Whether whole induction system has ammonia to reveal, it is ensured that the safety of whole system.
Improve further, also include compressed air conveyer device, including air relief valve, Pressure gauge, check-valves and compressed air Endless tube, compressed air compressed air endless tube distributes to each ejecting gun, and ejecting gun is two-fluid spray gun.Compressed air pressure By air relief valve, position about 0.3Mpa, ensures that compressed air pressure, Pressure gauge show post-decompression compressed air pressure.Non-return Valve purpose is to prevent ammonia from flowing backward in compressed air piping.Post-decompression compressed air enters compressed air endless tube, passes through ring Every ejecting gun is given in pipe uniform distribution.Use two-fluid spray gun, become droplet to spray in flue ammonia atomization by compressed air, Increase and the contact area of sulfur dioxide, improve reaction efficiency.
Ammonia in groove tank car is transferred in tank used for storing ammonia by ammonia by unloading ammonia pump, can have SNCR denitration in cement plant System, uses ammonia to be provided with as the denitrating system of reducing agent and unloads ammonia pump and tank used for storing ammonia, so the present invention unloads ammonia without separately setting Pump and tank used for storing ammonia are to reduce investment outlay, and cement kiln flue gas desulphurization system of the present invention can utilize the equipment of SNCR denitration system, Most equipment can share with denitrating system, reduces by a cost of investment, and operational management is convenient.
Improving further, described ejecting gun is branched, and spray site is uniformly arranged on the inwall of second level preheater windspout barrel On, the spray angle of ejecting gun is 20-40 degree, and ejecting gun is lateral spray type spray gun, and the side spray yawing moment phase of all ejecting guns With, deflection angle is 0-30 degree.By ejecting gun is set to lateral spray type, ammonia spraying is made to form hoop eddy flow stream in flue , fully ensure that area coverage.Because direct injection spray gun has bigger blind area near the walling of flue of ring-shaped flue, and center Territory lap is more, so using lateral spray type spray gun can reduce blind area and overlapping region, increases area coverage.
A kind of method using cement kiln flue gas desulphurization system to carry out desulfurization, comprises the steps:
Step one, the ammonia of configuration 15%-25%, and be transported in tank used for storing ammonia；
Step 2, set SO by automatic control system2Concentration preset value, detection device detects cement kiln in real time and divides in advance SO in solution system flue gas2Concentration, and measured value is sent to automatic control system, automatic control system is according to preset value and actual measurement The deviation of value calculates, adjusts the emitted dose of ammonia in real time；
Step 3, according to the ammonia water spray amount calculated in step 2, by ammonia injecting jet after delivery pump supercharging Being injected in after rifle in cement kiln precalcining system, injection is positioned at the exit of cement kiln second level preheater windspout barrel, and second The temperature in level preheater exit is 350～500 DEG C；The ammonia sprayed into and SO in flue gas2Generation desulphurization reaction:
SO2Absorption process: 2NH3+H2O+SO2→(NH4)2SO3(1-1)；
Oxidizing process: (NH4)2SO3+O2→(NH4)2SO4(1-2)；
Decomposition reaction: 3 (NH4)2SO4→4NH3+N2+3SO2+6H2O (1-3)；
Resorption process: 2SO2+2CaO+O2→2CaSO4(1-4)；
Wherein, SO2Absorption process and (NH4)2SO3Oxidizing process occurs in the preheater of the second level, rich in having in flue gas The oxygen of about 10%.Ammonia and SO in the cyclone cylinder of the second level2React generation ammonium sulfite, sulfurous under excess oxygen Acid ammonium can be oxidized to ammonium sulfate, and ammonium sulfate is attached on raw material with material to whereabouts, and now temperature can raise, and ammonium sulfate exists 280 DEG C start to decompose, have higher resolution ratio, decompose completely more than 513 DEG C more than 500 DEG C, produce NH after decomposition3、 N2、SO2And H2O, the SO of generation2A part is absorbed by CaO in raw material and generates CaSO4Enter dore furnace, part CaSO4Pyrolytic Participate in the sulfur cycle process of quality coal in cement kiln systems, undecomposed CaSO4It is discharged kiln system；The SO that another part rises with flue gas2Enter Enter and second level preheater continues and ammonia reaction generation ammonium sulfate, form circulation, until most SO2All rows of being cured Go out.
The main influence factor of desulfuration efficiency is the position of injection reaction zone, and main consideration is chosen in the position of ammonia water spray point Following factor:
1) spray site should be positioned at kiln system SO2After producing position, according to quality coal in cement kiln systems SO2Mechanism of production, in raw material Sulfide at 300～600 DEG C of oxidized generation SO2Gas, occurs mainly in the second level cyclone cylinder of five (four) level preheaters Or the third level cyclone cylinder of six grades of preheaters.
2) desulfurization reaction zone temperature to be avoided is too high, because desulfurization product ammonium sulfate high temperature can decompose moment, causes desulfurization Efficiency reduces.Desulfurizing agent absorbs SO2Mainly producing ammonium sulfate, ammonium sulfite, ammonium sulfite can be oxidized to ammonium sulfate, sulphuric acid Ammonium starts to decompose at 280 DEG C, has higher resolution ratio, decompose completely more than 513 DEG C more than 500 DEG C.Cement kiln Two grades of cyclone cylinder outlet temperatures are generally 350～500 DEG C, and third level cyclone cylinder outlet temperature is 550～650 DEG C.
3), in spray site is chosen at cement kiln precalcining system, desulphurization reaction product can be brought into next stage with raw material Cyclone cylinder in, participate in the sulfur cycle of kiln system, even directly with somehow be expelled directly out, whole system investment and operating cost meeting It is greatly decreased.
Therefore, spray ammonia position is arranged on preheater cyclone mouth exit, the second level by the present invention, can meet simultaneously more than Three requirements, reach to improve desulfuration efficiency, the purpose of reduction desulphurization cost.
Sulfur removal technology involved in the present invention after starting to spray ammonia, SO2Concentration is down to emission limit by initial value 100mg/m3Hereinafter needing 20～30min, the ammonium sulfate being primarily due to desulphurization reaction generation enters the rotation of higher level with material Can produce after in air duct to decompose at high operating temperatures and produce N2、NH3、SO2, decompose meeting after the SO2 produced moves upward along with flue gas Again by ammonia absorption, a SO is formed2Circulation.Part SO2Absorbed by the CaO in kiln system and aoxidize production calcium sulfate, entering Enter kiln system and participate in the sulfur cycle of kiln system self, finally solidify discharge.Therefore, start to spray SO after ammonia2Will not reduce moment, Meeting minimizing slowly, actual Engineering Projects also demonstrates that so.
It addition, CaCO3Itself is to SO2Absorption efficiency the lowest, but containing moisture in the ammonia sprayed into, water and SO2Reaction Generate sulfurous acid, sulfurous acid and and raw material in CaCO3React generation CO2And CaSO3, the existence of water can promote CaCO3Right SO2Assimilation effect, CaSO3At O2In the presence of can be oxidized to CaSO4, CaSO4Enter kiln system with material, participate in kiln The sulfur cycle of system or be discharged.Owing to cement kiln flue-gas temperature is the highest, water and SO2Reaction time is short, Therefore the amount that this partial reaction occurs is less.
Compared with prior art, there is advantages that
1, according to the mechanism of production of cement kiln sulfur dioxide, the sulfide in raw material starts near third level cyclone cylinder Generate sulfur dioxide, after desulfurizing agent inlet zone sulfur dioxide to be positioned at produces position, to ensure desulfurized effect, to avoid simultaneously Inlet zone temperature is too high, directly by Decomposition of ammonium sulfate.Therefore inlet zone is normally at the second level outlet of five-stage whirlwind cylinder, improves Desulfurized effect.Inventive desulfurization efficiency is up to more than 95%, and desulfuration efficiency is high；By automatic control system, detection device real-time Calculate, adjust the emitted dose of ammonia, SO2With NH3 mol ratio 1:2-1:2.5 in ammonia, operating cost is low.
2, sulfur removal technology involved in the present invention can adjust ammonia flow in real time according to sulfur dioxide emissioning concentration, it is achieved from Dynamicization controls, it is ensured that desulfuration efficiency, while accurately controlling ammonia flow, it is to avoid the escaping of ammonia is too high causes equipment corrosion.
3, the desulfurizing agent supply unit of the present invention uses multistage centrifugal transport pump, metering distribution system to use pneumatic regulation Valve controls flow.Conveying and metering distribution system are integrated into a set of equipment, modularized design, and floor space is little, and the construction period is short, Control system is incorporated into original denitrating system, or a set of new system of independent design, and operational management is convenient.
4, the present invention uses two-fluid spray gun, uses the mode of hoop eddy flow to spray in flue by desulfurizing agent, it is ensured that to cover Area and the time of staying are to reach optimal desulfuration efficiency.
5, the present invention uses ammonia as desulfurizing agent, runs under the high temperature conditions, and cost of investment is low, stable, to kiln The impact of system is less.
Accompanying drawing explanation
Fig. 1 is cement kiln flue gas desulphurization system schematic diagram of the present invention.
Fig. 2 is cement decomposing furnace of the present invention, cement kiln precalcining system schematic diagram.
Fig. 3 is lateral spray type Flow Field Distribution schematic diagram in embodiment one.
Fig. 4 is direct injection Flow Field Distribution schematic diagram in comparative example one.
Detailed description of the invention
For making the purpose of the present invention and technical scheme clearer, below in conjunction with the embodiment of the present invention skill to the present invention Art scheme is clearly and completely described.
Embodiment one:
As it is shown in figure 1, a kind of cement kiln flue gas desulphurization system, the ammonia in groove tank car is turned by ammonia by unloading ammonia pump 1 Move in tank used for storing ammonia 2, SNCR denitration system in cement plant, can be had, use ammonia can be provided with as the denitrating system of reducing agent Unload ammonia pump and tank used for storing ammonia, so the present invention typically the most separately sets unloads ammonia pump 1 and tank used for storing ammonia 2 to reduce investment outlay.At tank used for storing ammonia Outlet is provided with out/stops the main valve 3 of desulphurization system ammonia supply and drives/stop the second main valve 4 of denitrating system ammonia supply, in order to Time switching different system ammonia supply.
In the present embodiment, desulphurization system uses two centrifugal delivery pumps 5 to carry ammonia, and the using and the reserved, by regulating back Stream valve 6 regulates capacity of returns to control the discharge pressure of ammonia, and the ammonia discharge pressure table 7 on return duct shows ammonia conveying pressure Power.The flow of ammonia is controlled by the valve opening of regulation pneumatic control valve 8, can examine in real time according to kiln tail on-line measuring device Survey SO2Concentration carry out controlling opening of valve, reach the purpose automatically controlled.Needle-valve 9 is maintenance bypass valve；It addition, when pneumatic When regulation valve 8 ammonia conveying is fully open, the flow of ammonia still cannot meet requirement, can suitably supplement ammonia aqua stream by needle-valve 9 Amount.The flow monitoring of ammonia is detected by electromagnetic flowmeter 10.Pressure switch 11 detects the pressure of whole system, during hypertonia Can report to the police shutdown system, ammonia leak detector 12 detects whether whole induction system has ammonia to reveal, it is ensured that the peace of whole system Entirely.
Ammonia is evenly distributed to each ejecting gun 18 after entering ammonia endless tube 17.Ejecting gun 18 uses two-fluid spray gun, Compressed air is utilized to be sprayed in flue by ammonia.Compressed air pressure position about 0.3Mpa, ensures compression by air relief valve 13 Air pressure, Pressure gauge 14 shows post-decompression compressed air pressure.Check-valves 15 purpose is to prevent ammonia from flowing backward to compression sky In feed channel.Post-decompression compressed air enters compressed air endless tube, is evenly distributed to every spray gun by endless tube.
When ammonia enters inlet zone, according to high temperature ammonia process reaction mechanism and cement kiln SO2Mechanism of production, inlet zone temperature Can not be too high, prevent Decomposition of ammonium sulfate, the SO produced in also needing to ensure all of stove2All through conversion zone, most suitable position Setting on two grades of cyclone cylinder exhaust pass, as shown in Figure 2.
As it is shown on figure 3, set six ejecting guns, a diameter of 6m of second level preheater windspout barrel, ejecting gun atomization distance is equal Taking 3.5m, spray angle is 30 °, uses lateral spray type ejecting gun, and deflection angle α is 19 °, then the flue cross section ammonia of six direct-injection rifles Water spray coverage rate is 44.66%.
The mode of choosing of side spray rifle spray angle α is: according to spray gun quantity n, flue diameter is divided into n spray site, even Meeting adjacent ejected dots AB, take the center line C of AB, connecting the midpoint D of OC, OC with the line of spray site A is spray centerline, AD and OA Angle be jet angle α, through calculating, the area coverage of this jet angle has a distinct increment compared with the area coverage of direct injection spray gun, Thus reach to improve reaction efficiency, reduce the purpose of ammonia consumption.
Comparative example one:
As shown in Figure 4, if six ejecting guns, use direct injection to arrange, i.e. a diameter of 6m of second level preheater windspout barrel, Ejecting gun atomization distance all takes 3.5m, and spray angle is 30 °, and other are identical with embodiment one.It is computed, six direct-injection rifles Flue cross section ammonia spraying coverage rate is 34.95%.
Embodiment one and comparative example one compare:
By contrast, using lateral spray type ejecting gun relatively and direct injection is arranged, coverage rate adds than direct injection spray gun 9.71%, thus reach to improve desulphurization reaction efficiency, reduce the purpose of ammonia consumption.
Embodiment two:
A kind of method using cement kiln flue gas desulphurization system to carry out desulfurization, comprises the steps:
Step one, the ammonia of configuration 15%-25%, and be transported in tank used for storing ammonia；
Step 2, set SO by automatic control system2Concentration preset value, detection device detects cement kiln predecomposition in real time SO in system flue gas2Concentration, and measured value is sent to automatic control system, automatic control system is according to preset value and measured value Deviation calculate, adjust the emitted dose of ammonia in real time；
Step 3, according to the ammonia water spray amount calculated in step 2, by ammonia injecting jet after delivery pump supercharging Being injected in after rifle in cement kiln precalcining system, injection is positioned at the exit of cement kiln second level preheater windspout barrel, and second The temperature in level preheater exit is 350～500 DEG C；The ammonia sprayed into and SO in flue gas2Generation desulphurization reaction:
SO2Absorption process: 2NH3+H2O+SO2→(NH4)2SO3(1-1)；
Oxidizing process: (NH4)2SO3+O2→(NH4)2SO4(1-2)；
Decomposition reaction: 3 (NH4)2SO4→4NH3+N2+3SO2+6H2O (1-3)；
Resorption process: 2SO2+2CaO+O2→2CaSO4(1-4)；
Wherein, SO2Absorption process and (NH4)2SO3Oxidizing process occurs in the preheater of the second level, rich in having in flue gas The oxygen of about 10%.Ammonia and SO in the cyclone cylinder of the second level2React generation ammonium sulfite, sulfurous under excess oxygen Acid ammonium can be oxidized to ammonium sulfate, and ammonium sulfate is attached on raw material with material to whereabouts, and now temperature can raise, and ammonium sulfate exists 280 DEG C start to decompose, have higher resolution ratio, decompose completely more than 513 DEG C more than 500 DEG C, produce NH after decomposition3、 N2、SO2And H2O, the SO of generation2A part is absorbed by CaO in raw material and generates CaSO4Enter dore furnace, part CaSO4Pyrolytic Participate in the sulfur cycle process of quality coal in cement kiln systems, undecomposed CaSO4It is discharged kiln system；The SO that another part rises with flue gas2Enter Enter and second level preheater continues and ammonia reaction generation ammonium sulfate, form circulation, until most SO2All rows of being cured Go out.
The main influence factor of desulfuration efficiency is the position of injection reaction zone, and main consideration is chosen in the position of ammonia water spray point Following factor:
1) spray site should be positioned at kiln system SO2After producing position, according to quality coal in cement kiln systems SO2Mechanism of production, in raw material Sulfide at 300～600 DEG C of oxidized generation SO2Gas, occurs mainly in the second level cyclone cylinder of five (four) level preheaters Or the third level cyclone cylinder of six grades of preheaters.
2) desulfurization reaction zone temperature to be avoided is too high, because desulfurization product ammonium sulfate high temperature can decompose moment, causes desulfurization Efficiency reduces.Desulfurizing agent absorbs SO2Mainly producing ammonium sulfate, ammonium sulfite, ammonium sulfite can be oxidized to ammonium sulfate, sulphuric acid Ammonium starts to decompose at 280 DEG C, has higher resolution ratio, decompose completely more than 513 DEG C more than 500 DEG C.Cement kiln Two grades of cyclone cylinder outlet temperatures are generally 350～500 DEG C, and third level cyclone cylinder outlet temperature is 550～650 DEG C.
3), in spray site is chosen at cement kiln precalcining system, desulphurization reaction product can be brought into next stage with raw material Cyclone cylinder in, participate in the sulfur cycle of kiln system, even directly with somehow be expelled directly out, whole system investment and operating cost Can be greatly decreased.
Therefore, spray ammonia position is arranged on preheater cyclone mouth exit, the second level by the present invention, can meet simultaneously more than Three requirements, reach to improve desulfuration efficiency, the purpose of reduction desulphurization cost.
Sulfur removal technology involved in the present invention after starting to spray ammonia, SO2Concentration is down to emission limit by initial value 100mg/m3Hereinafter needing 20～30min, the ammonium sulfate being primarily due to desulphurization reaction generation enters the rotation of higher level with material Can produce after in air duct to decompose at high operating temperatures and produce N2、NH3、SO2, decompose meeting after the SO2 produced moves upward along with flue gas Again by ammonia absorption, a SO is formed2Circulation.Part SO2Absorbed by the CaO in kiln system and aoxidize production calcium sulfate, entering Enter kiln system and participate in the sulfur cycle of kiln system self, finally solidify discharge.Therefore, start to spray SO after ammonia2Will not reduce moment, Meeting minimizing slowly, actual Engineering Projects also demonstrates that so.
It addition, CaCO3Itself is to SO2Absorption efficiency the lowest, but containing moisture in the ammonia sprayed into, water and SO2Reaction Generate sulfurous acid, sulfurous acid and and raw material in CaCO3React generation CO2And CaSO3, the existence of water can promote CaCO3Right SO2Assimilation effect, CaSO3At O2In the presence of can be oxidized to CaSO4, CaSO4Enter kiln system with material, participate in kiln The sulfur cycle of system or be discharged.Owing to cement kiln flue-gas temperature is the highest, water and SO2Reaction time is short, Therefore the amount that this partial reaction occurs is less.
The present invention does not does illustrate be prior art or can be realized by prior art, and the present invention Described in be embodied as case and be only the preferable case study on implementation of the present invention, be not used for limiting the practical range of the present invention. The most all equivalence changes made according to the content of scope of the present invention patent and modification, all should be used as the technology category of the present invention.

Claims (7)

1. a cement kiln flue gas desulphurization system, it is characterised in that include that tank used for storing ammonia, delivery pump, ejecting gun, cement decompose Stove, cement kiln precalcining system and automatic control system, cement kiln precalcining system includes multistage preheater, described tank used for storing ammonia Being connected with ejecting gun by delivery pump, the spray site of ejecting gun is positioned at the exit of second level preheater windspout barrel, and ejecting gun is extremely Few one；Pneumatic control valve it is provided with, cement kiln predecomposition system on pipeline between the port of export and the ejecting gun of described delivery pump System is provided with detection device, is electrically connected between detection device and pneumatic control valve and automatic control system.
Cement kiln flue gas desulphurization system the most according to claim 1, it is characterised in that also include return duct, described time One end of flow tube connects with the port of export of ammonium hydroxide delivery pump, and the other end connects with tank used for storing ammonia, and return duct is provided with reflux inlet With ammonia discharge pressure table.
Cement kiln flue gas desulphurization system the most according to claim 1 and 2, it is characterised in that described delivery pump is two, And be arranged in parallel, it is provided with system main valve between delivery pump and tank used for storing ammonia.
Cement kiln flue gas desulphurization system the most according to claim 3, it is characterised in that the port of export of described delivery pump with Needle-valve, electromagnetic flowmeter, pressure switch, ammonia leak detector and ammonia endless tube it is provided with on pipeline between ejecting gun；Wherein, Pneumatic control valve is arranged in parallel with needle-valve, and ammonia is evenly distributed to each ammonia water spray rifle after entering ammonia endless tube.
Cement kiln flue gas desulphurization system the most according to claim 4, it is characterised in that also include compressed air conveying dress Putting, including air relief valve, Pressure gauge, check-valves and compressed air endless tube, compressed air compressed air endless tube distributes to each Ejecting gun, ejecting gun is two-fluid spray gun.
Cement kiln flue gas desulphurization system the most according to claim 1, it is characterised in that described ejecting gun is branched, spray Exit point even distribution is on the inwall of second level preheater windspout barrel, and the spray angle of ejecting gun is 20-40 degree, and ejecting gun is side Spray formula spray gun, and the side spray yawing moment of all ejecting guns is identical, deflection angle is 0-30 degree.
7. one kind uses the method that cement kiln flue gas desulphurization system described in claim 1-6 carries out desulfurization, it is characterised in that bag Include following steps:
Step one, the ammonia of configuration 15%-25%, and be transported in tank used for storing ammonia；
Step 2, set SO by automatic control system2Concentration preset value, detection device detects cement kiln precalcining system in real time SO in flue gas2Concentration, and measured value sends to automatic control system, automatic control system is inclined according to preset value and measured value Difference calculates, adjusts the emitted dose of ammonia in real time；
Step 3, according to the ammonia water spray amount calculated in step 2, by ammonia after delivery pump supercharging after injecting jet rifle Being injected in cement kiln precalcining system, spray site is positioned at the exit of cement kiln second level preheater windspout barrel, the second level The temperature in preheater exit is 350～500 DEG C；The ammonia sprayed into and SO in flue gas2Generation desulphurization reaction:
SO2Absorption process: 2NH3+H2O+SO2→(NH4)2SO3(1-1)；
Oxidizing process: (NH4)2SO3+O2→(NH4)2SO4(1-2)；
Decomposition reaction: 3 (NH4)2SO4→4NH3+N2+3SO2+6H2O (1-3)；
Resorption process: 2SO2+2CaO+O2→2CaSO4(1-4)；
Wherein, SO2Absorption process and (NH4)2SO3Oxidizing process occurs in the preheater of the second level, (NH4)2SO4Decomposition reaction In three grades of preheaters, resorption process occurs in dore furnace, rich in the oxygen having about 10% in flue gas.
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CN108014610A (en) * 2018-01-05 2018-05-11 靳新令 Ammonia desulfurizing process and its desulfurizer
CN108079776A (en) * 2017-11-24 2018-05-29 北京绿岩环保科技有限责任公司 A kind of new dry process rotary kiln catalytic desulfurizing agent and its preparation and application
CN108439319A (en) * 2018-02-27 2018-08-24 海宁市富升裘革有限公司 A kind of safe discharging system of formic acid
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CN111389192A (en) * 2020-04-13 2020-07-10 湖南萃智咨询服务有限公司 Dry-method cement kiln tail flue gas desulfurization method
CN112619403A (en) * 2020-12-01 2021-04-09 贵州省鑫瀚蓝环保科技有限公司 Cement kiln semi-dry desulfurization system design
CN114733329A (en) * 2022-04-02 2022-07-12 南京西普环保科技有限公司 Dry desulfurization process and dry desulfurization device for cement clinker
CN115974435A (en) * 2023-01-10 2023-04-18 福建龙麟环境工程有限公司 Dynamic sulfur suppression system and method for novel dry-process cement kiln under automatic control of DCS

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CN106731465A (en) * 2016-12-30 2017-05-31 西安交通大学 Alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooled down
CN106731465B (en) * 2016-12-30 2019-08-09 西安交通大学 Alkali sulphur absorbs low-temperature corrosion preventing control method when a kind of coal-fired flue-gas depth is cooling
CN108079776A (en) * 2017-11-24 2018-05-29 北京绿岩环保科技有限责任公司 A kind of new dry process rotary kiln catalytic desulfurizing agent and its preparation and application
CN108014610A (en) * 2018-01-05 2018-05-11 靳新令 Ammonia desulfurizing process and its desulfurizer
CN108439319A (en) * 2018-02-27 2018-08-24 海宁市富升裘革有限公司 A kind of safe discharging system of formic acid
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CN109865417A (en) * 2019-03-05 2019-06-11 南京西普环保科技有限公司 A kind of denitration integrated device and reducing agent flow rate adjusting method
CN111389192A (en) * 2020-04-13 2020-07-10 湖南萃智咨询服务有限公司 Dry-method cement kiln tail flue gas desulfurization method
CN112619403A (en) * 2020-12-01 2021-04-09 贵州省鑫瀚蓝环保科技有限公司 Cement kiln semi-dry desulfurization system design
CN114733329A (en) * 2022-04-02 2022-07-12 南京西普环保科技有限公司 Dry desulfurization process and dry desulfurization device for cement clinker
CN115974435A (en) * 2023-01-10 2023-04-18 福建龙麟环境工程有限公司 Dynamic sulfur suppression system and method for novel dry-process cement kiln under automatic control of DCS

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