A kind of improved Cascade ammonia process of desulfurization denitrating tower
The utility model relates to a kind of improved Cascade ammonia process of desulfurization denitrating tower, belongs to technical field of chemical.
China's per GDP sulfur dioxide and nitrogen oxide emission are the several times of developed country.SO
2be the topmost atmosphere pollution of China, China is maximum in the world SO
2discharge country, discharge capacity ranks first in the world, and has surpassed the self-purification capacity of China's atmospheric environment, and year precipitation pH value is less than 5.6 region and accounts for 40% of area, causes tremendous economic loss.Statistics shows, the first half of the year in 2011, in four large major pollutants the binding indicators, COD, SO2 emissions continue to decline, but newly-increased index ammonia nitrogen discharge capacity only declines 0.73%, and nitrogen oxide emission rises 6.17% on the contrary.Along with the development of Technological Economy, the going deep into of circular economy concept, ammonia process highlights its advantage, except desulfuration efficiency is high, has also developed and has removed part NO
xtechnology.Adopt ammonia fertilizer method flue gas desulfurization and denitrification technology, reclaim low concentration SO
2, and remove nitrogen oxides in effluent, and produce ammonium sulfate fertilizer, both solved exhaust emission problem, valuable pollution treatment byproduct is provided again, there is higher technology content, development prospect is wide, meets the strategy of sustainable development.
Traditional Cascade ammonia process of desulfurization denitrating tower all adopts void tower structure at absorber portion, and absorptivity is low, and operating cost is relatively high.
Improved Cascade ammonia process of desulfurization denitrating tower of the present utility model, by literature search, has no the open report identical with the utility model.
Summary of the invention:
The purpose of this utility model is, for flue gas SO
3effectively remove and improve denitration efficiency, utilize different gas-liquid contact modes to have complementary functions, provide a kind of equipment low operating cost low, thermal-arrest flue gas is cooling, cleaning dust, ammonium sulfate liquid concentrated, SO
2absorb and NO
xreduction removes, sulfite oxidation, the improved Cascade ammonia process of desulfurization denitrating tower being integrated except ammonia mist and aerosol, water smoke function.
Improved Cascade ammonia process of desulfurization denitrating tower of the present utility model, be the improvement on the < < ZL201220593699.3 > > basis of inventor design, improvement is: between the absorption spray equipment (15) of absorber portion (4) and air-spreading disk (14), be set to void tower structure; Absorb between spray equipment (15) depending on the requirement of absorptivity being all set to filler (16) or one deck and filler (16) one deck is set or not filler (16).After improvement, improve gas-liquid contact specific area, improve SO
2absorptivity; Reduce sprinkle density simultaneously, thereby reduce energy consumption, reduce operating cost; Can also further reduce ammonia-spillage amount.
Operation principle of the present utility model is identical with < < ZL201220593699.3 > > " Cascade ammonia process of desulfurization denitrating tower ".But absorbing gas-liquid mass transfer on hollow-spraying-tower gas and Drop Mass Transfer basis, utilized the high-specific surface area of filler, in the situation that liquid spray flux is little, liquid film area is large, turbulence is large, Surface Renewal is fast, has improved gas-liquid mass transfer efficiency.
The utility model is except having original equipment reduced investment, and thermal-arrest flue gas is cooling, cleaning dust, ammonium sulfate liquid are concentrated, SO
2absorb and NO
xreduction removes, sulfite oxidation, except the advantage that ammonia mist and aerosol, water smoke function are integrated, and its SO
2absorptivity further improves, and operating cost reduces obviously.
Accompanying drawing explanation:
Accompanying drawing is the utility model device structure schematic diagram.
The specific embodiment:
Novel Cascade ammonia process of desulfurization denitrating tower of the present utility model, by top, be provided with the tower body 1 of cigarette fontanel 22, be arranged on absorption liquid circulation section 7 from the bottom to top in tower body 1, oxidation panel 6, washing temperature descending section 5, absorber portion 4, strengthening is except ammonia mist section 3 and high-efficient defoaming section 2, the demister 21 and the fresh water (FW) that are arranged on high-efficient defoaming section 2 rinse contrary spray spray thrower 20, be arranged on strengthening except efficient ammonia day with fog 18 and the filler 16 of removing of ammonia mist section 3, fresh water (FW) rinses along spray spray thrower 19, liquid dish and gas distributor 17, what be arranged on absorber portion 4 comprises air-spreading disk 14, bottom is that void tower absorbs spray equipment 15, top is filler 16 and spray equipment 15, be arranged on the ammonium sulfate of washing temperature descending section 5 or contain ammonium nitrate solution spray equipment 13 and gas approach 12, be arranged on the process pipe 11 outside oxidation panel 6 tower bodies 1, be arranged on microporous aeration device 10 and the dividing plate with holes 9 of oxidation panel 6, the liquid-phase catalyst distributor 8 that is arranged on absorption liquid circulation section 7 forms, wherein: be arranged between the absorption spray equipment 15 of absorber portion 4 and air-spreading disk 14 and be set to void tower structure, absorb on spray equipment 15 depending on the requirement of absorptivity being arranged to one deck or two layers of filler 16.
The utility model is prepared according to a conventional method, and structure is if accompanying drawing is to show.The course of work is:
1, the hot flue gas of 120～180 ℃ after gathering dust, enter desulphurization denitration tower washing temperature descending section 5, with ammonium sulfate (containing ammonium nitrate) the solution counter current contacting of top spray, by the washing of ammonium sulfate (containing ammonium nitrate) liquid, flue gas in this process because adiabatic evaporation is cooling.Part NO is oxidized to NO by the oxygen in flue gas
2be absorbed.The heat of flue gas evaporates and concentrated reaching capacity part moisture in solution, send the magma being arranged at outside tower groove, separates out sulphur ammonium crystal grain, and in magma groove, supernatant is evaporated by 5 circulations of pumping washing temperature descending section again.Magma groove magma content reaches regulation technology controlling and process index, pumping sulphur ammonium operation.
2, flue gas is through the 5 washing coolings of washing temperature descending section, and temperature is cooled to approximately～50 ℃ by 120～180 ℃, by washing section upper gas distributor 14, enters absorber portion.At absorber portion 4, flue gas by the absorber portion of void tower section and filler 16 combinations, absorbs SO from bottom to top through absorption liquid countercurrent spray
2extrusion rate > 98%, part NO
xbe reduced to N
2and deviate from.
3, the major part of absorption liquid enters absorption liquid circulation section 7, squeezes into absorber portion continue circulated sprinkling absorption after supplementary ammonia absorption liquid regeneration with pump.At absorption liquid circulation section 7, liquid-phase catalyst distributor 8 is set, under the effect of trace catalyst, can improves NO
xeliminating efficiency.6 of absorption liquid circulation section 7 and oxidation panels are provided with dividing plate with holes, and the amount of liquid that controlling absorption process increases enters oxidation panel, can guarantee that absorption, oxidation are independent of each other.Absorption liquid partly enters oxidation panel 6, and the microporous aeration device 10 at oxidation panel 6 middle parts, passes into compressed air, and the ammonium sulfite in oxidizing tower in absorption liquid is oxidized to ammonium sulfate, and sub-salt oxygenation efficiency is more than 99%.
4, purifying smoke enters strengthening except ammonia mist section 3 through absorber portion top, in strengthening, except configuring one-levels, ammonia mist section 3 efficiently removes ammonia day with fog 18 and one deck filler 16, demister adopts ripe corrugated cardboard sheet to be arranged in parallel and forms, be furnished with fresh water (FW) and rinse along spray spray thrower 19, rinse and reclaim ammonia mist and the aerosol of demister trapping.Efficient except ammonia day with fog 18 and the control partition flushing chronologically of filler 16 use fresh water (FW)s, to prevent that efficient demister 18 and filler 16 from stopping up, guarantee foam removal efficiency simultaneously, minimizing system ammonia-spillage amount, raising system ammonia utilization rate, the recovery utilization rate that guarantees ammonia reaches more than 98%, guarantees amount of ammonia slip≤10mg/Nm
5, purifying smoke removes ammonia mist section 3 tops through strengthening and enters high-efficient defoaming section 2, the smoke gas flow that contains droplet is when demister 21 passage, the effect of impact of drop and demister 21, effect of inertia, turn to centrifugal force and with rubbing action, the suction-operated of corrugated sheet, drop is captured, be furnished with fresh water (FW) and rinse contrary spray spray thrower 20, the drop that flushing is captured, the droplet content mean value after foam removal is less than 75mg/Nm
3(size droplet diameter is greater than 15 μ m).The escaping of ammonia≤10mg/Nm
The utility model is used and shows, can reach designing requirement completely.