Summary of the invention
The object of the present invention is to provide a kind of ammonia method desulfurizing method, this technology has the desulfurization degree height, and operation troubles is low, and maintenance is convenient, ease ammonia and ammonium sulfate and advantages such as the ammonium sulfite aerosol load is low, the accessory substance dust-laden is few, quality better in the outlet flue gas.
The equipment that another object of the present invention is to provide in the ammonia desulfurizing process and adopted.This high-efficiency desulfurization tower adopts spray and column plate reasonably to be provided with, and the ammonium salt oxidation tank is set outside tower, make sulfide and the flue dust of desulfurizing tower in can more high efficiency absorption flue gas, and this Apparatus and method for carries out desulfurization to the high flue gas of dust content and also is suitable for.
To achieve these goals, the technical solution used in the present invention is:
A kind of ammonia method desulfurizing method, described method comprises that the flue gas that will come out from boiler enters desulfurizing tower from smoke inlet, enter one-level spray section, column plate layer and demister and absorb processing, it is characterized in that: before after flue gas absorbs by the column plate layer, entering demister, enter the secondary spray section and absorb; The absorption liquid of described one-level spray section, column plate layer, secondary spray section is all squeezed into the solution pool at the bottom of the tower and is absorbed, and the ammonium bisulfite utilization at the bottom of the described tower in the solution pool is injected ammonia it is reduced into ammonium sulfite from the notes ammonia pipe that links to each other with solution pool at the bottom of the tower.Ammonia can inject with the form of gas ammonia or ammoniacal liquor.
Described secondary spray section sprays absorption liquid by spray equipment, absorbs desulfurization; Described spray equipment is the 1-2 layer.
Described one-level spray section is made up of 1-3 layer spray equipment.
Described column plate layer is for being 1-2 layer column plate.
Regularly clean among the present invention the used rinse water of described demister as a supplement water flow at the bottom of the tower of desulfurizing tower in the solution pool.
The temperature of the flue gas that comes out from boiler described in the present invention is 120-160 ℃.
Preferred described flue gas can tentatively be lowered the temperature by cooling heat exchanger or cooling spray equipment before entering desulfurizing tower among the present invention, was cooled to 80-100 ℃.
Method of the present invention is further comprising the steps of: the absorption liquid of described column plate layer flow to solution pool at the bottom of the tower of desulfurizing tower to the absorption liquid of underflow stream and one-level spray section, secondary spray section by downspout; Be deposited in the accident solution pool of dust outside discharge pipe drains into tower of desulfurizing tower bottom, it is carried out sedimentation separation, to return pump by accident solution through the supernatant of sedimentation separation gained again and return in the desulfurizing tower and continue to absorb as absorption liquid, the mud of sedimentation is discharged by sludge pump in the accident solution pool.
Method of the present invention also comprises: at the bottom of the tower of desulfurizing tower in the solution pool solution squeeze into the ammonium salt oxidation tank from discharge pipe by excavationg pump, deflate or oxygen becomes ammonium sulfate with sulfite oxidation from the oxidation fan that links to each other with the ammonium salt oxidation tank, and then ammonium sulfate is discharged to through discharge pipe becomes ammonium sulfate fertilizer after drying system carries out drying.
Absorption liquid in described one-level spray section, secondary spray section and the column plate layer is concentration 10%~40% ammonium sulfite solution.
Employed device comprises a desulfurizing tower 7 among the present invention, described desulfurizing tower comprises solution pool 8 at the bottom of the tower of desulfurizing tower, one-level spray section 2, column plate layer 3, secondary spray section 4 from the bottom to top, demister 5 is equipped with in described secondary spray section 4 tops, links to each other with the top exhanst gas outlet 6 of desulfurizing tower; The lower position that is positioned at one-level spray section 2 at the middle part of desulfurizing tower is provided with smoke inlet 1; The side of solution pool 8 links to each other with notes ammonia pipe 9 at the bottom of the tower of described desulfurizing tower; Be outside equipped with three circulating pumps 11 at tower, the outlet of above-mentioned circulating pump 11 links to each other with one-level spray section 2, column plate layer 3, secondary spray section 4 respectively, and above-mentioned inlet of circulating pump links to each other with solution pool 8 at the bottom of the tower of desulfurizing tower respectively.
Device used in the present invention links to each other with ammonium salt oxidation tank 13 outside the tower by excavationg pump 12 in the bottom of solution pool 8 at the bottom of the tower of desulfurizing tower; Wherein the import of excavationg pump 12 links to each other with the discharge pipe 10 of solution pool at the bottom of the tower 8, and the outlet of excavationg pump 12 links to each other with the top of described ammonium salt oxidation tank 13; The below of described ammonium salt oxidation tank 13 links to each other with oxidation fan 15, also is provided with ammonium salt discharge pipe 14 at the middle part of ammonium salt oxidation tank 13.
The bottom of desulfurizing tower of the present invention links to each other by the top of the accident solution pool 17 outside comb 19 and tower of desulfurizing tower, one side of the below of accident solution pool 17 links to each other with sludge pump 18, the import that accident solution returns pump 16 links to each other with accident solution pool 17, and the outlet that accident solution returns pump 16 links to each other with solution pool 8 at the bottom of the tower of desulfurizing tower.
Specifically, a kind of ammonia method desulfurizing method, described method may further comprise the steps:
(1), 120~160 ℃ of high-temperature flue gas that come out from boiler enter the desulfurizing tower middle part from smoke inlet;
(2), above-mentioned flue gas rises in desulfurizing tower through the one-level spray section, by spray equipment spray absorption liquid, absorbs desulfurization, flue-gas temperature is reduced to 60-70 ℃, 30~50% sulfur dioxide is absorbed in the flue gas;
(3), carry out above-mentioned desulfurization after, flue gas continue to rise through the column plate layer, the absorption liquid that flows on the column plate fully contacts with flue gas, further removes sulfur in smoke, in this process in the flue gas sulfur dioxide more than 90% be absorbed;
(4), flue gas continuation rising enters the secondary spray section, this spray section sprays absorption liquid by spray equipment, absorb desulfurization, can absorb 30~50% sulfur dioxide and ease ammonia in the flue gas and ammonium sulfite aerosol in this spray section, last flue gas carries out discharging from the exhanst gas outlet of cat head after the demist through demister, and the rinse water of wherein regularly cleaning demister can be used as supplementing water and enters at the bottom of the tower of desulfurizing tower in the solution pool;
(5), the absorption liquid of column plate layer by downspout to underflow stream, all flow to solution pool at the bottom of the tower of desulfurizing tower at last with the absorption liquid of spray section, contain in ammonium sulfite, ammonium bisulfite and flue gas contained dust, the bottom of ash fall tower at the bottom of solution pool in the absorption liquid this moment; From the notes ammonia pipe that links to each other with solution pool at the bottom of the tower, inject ammonia, be reduced into ammonium sulfite absorbing the ammonium bisulfite that generates behind the sulfide in the absorption liquid;
(6), the solution at the bottom of the above-mentioned tower in the solution pool squeezes into one-level spray section, column plate layer, the secondary spray section of desulfurizing tower respectively by three circulating pumps that link to each other with solution pool at the bottom of the tower of desulfurizing tower, respectively as the absorption liquid of above-mentioned one-level spray section, column plate layer, secondary spray section.
Method of the present invention is further comprising the steps of: the desulfurizing tower bottom deposit has partially absorbing in the accident solution pool of liquid outside discharge pipe is discharged tower of most of dust, it is carried out sedimentation separation, to return in the desulfurizing tower by pump through the supernatant of sedimentation separation and continue to absorb as absorption liquid, the mud of sedimentation can be discharged by sludge pump.
Described method is further comprising the steps of: squeeze into the ammonium salt oxidation tank from discharge pipe by excavationg pump when the solution at the bottom of the tower of desulfurizing tower in the solution pool reaches finite concentration, utilize air or oxygen that sulfite oxidation is become ammonium sulfate at this, and then be discharged to through discharge pipe and become ammonium sulfate fertilizer after drying system carries out drying.
Solution pool, accident solution pool, circulating pump etc. all select for use the conventional ripening product to assemble at the bottom of spray equipment described in the present invention, column plate layer, demister, ammonium salt oxidation tank, the tower.
More particularly, the ammonia method desulfurizing method of the present invention's employing is:
120-160 ℃ high-temperature flue gas 2000 standard cubic meters of coming out from boiler/hours-1.2 * 10
6Standard cubic meter/hour, wherein sulfur-containing oxide 50-1600ppm makes high-temperature flue gas tentatively be cooled to 80-100 ℃ through cooling heat exchanger or cooling spray equipment, prevents the corrosion-inhibiting coating of too high flue-gas temperature destruction desulfurizing tower inwall; If corrosion-inhibiting coating is a high-temperaure coating, high-temperature flue gas also can directly enter desulfurizing tower so, flue gas rises after entering desulfurizing tower, at first pass through the one-level spray section, this spray section can comprise 1-3 layer spray equipment, carry out once more flue-gas temperature being dropped to interval 60-70 ℃ of the optimum temperature of desulfurization at this, ammonium sulfite in cooling in the spray liquid also absorbs the sulfide in the part of smoke, and the sulfide in ammonium sulfite and the flue gas reacts behind the back generation ammonium bisulfite with solution one solution pool at the bottom of the tower that rises and falls back; Above the desulfurizing tower spraying layer, be provided with the column plate layer, the column plate layer comprises 1-2 layer column plate, when the flue gas that reaches the desulfurization optimum temperature through spray rises to the column plate layer in desulfurizing tower, the absorption liquid that flows on the column plate fully contacts with flue gas, ammonium sulfite in the absorption liquid and the sulfide in the flue gas fully react, generate ammonium bisulfite, thereby the sulfide in the flue gas has been removed, the ammonium bisulfite of generation returns solution pool at the bottom of the tower from downspout again; Above column plate, also be provided with the one-level spray section, this layer spray can further absorb sulfide remaining in the flue gas, absorb the ease ammonia in the flue gas simultaneously, and the solution of spray drops on the column plate, help the even distribution of absorption liquid on the column plate, avoid when handling big exhaust gas volumn, the desulfurizing tower tower diameter is bigger, solution is difficult to evenly to distribute and influences the shortcomings such as absorption of sulfide in the flue gas on the column plate, absorption liquid at above-mentioned spray section and column plate layer is the ammonium sulfite solution of 10-40%, makes ammonia process of desulfurization new method of the present invention can apply to the processing of big exhaust gas volumn.During the demister of the flue gas of having carried ammonium sulfate and ammonium sulfite drop secretly by the desulfurizing tower top, collision by flue gas and blade, ease ammonia in the flue gas and the drop of carrying ammonium sulfate secretly are removed totally substantially, the regular water of ammonium sulfate that adheres on the demister and ammonium sulfite aerosol needs cleans, and the water that cleans demister enters solution pool at the bottom of the tower as the make-up water of desulfurizing tower.Clean flue gas heats the back or directly enters chimney by the flue gas heat exchange device then, enters atmosphere.
Solution pool at the bottom of the bottom of desulfurizing tower is to deposit the tower of absorption liquid, the absorption liquid of each spray section, column plate layer all are to get liquid by circulating pump in the solution pool at the bottom of this tower; Notes ammonia pipe by solution pool side at the bottom of the tower with ammonia with (NH
3Meter) with solution pool at the bottom of 0.15-2856 kilogram/hour injection tower, do not have the ammonium bisulfite of absorbability to react in ammonia and the solution this moment, is reduced into the ammonium sulfite that can absorb sulfide once more with having absorbed the ammonium bisulfite that generates in the solution behind the sulfide.When solution reaches finite concentration in the solution pool at the bottom of the tower (15%-40%), can solution solution pool at the bottom of the tower of desulfurizing tower be expelled to the ammonium salt oxidation tank by excavationg pump and carry out oxidation, the air or the oxygen that utilize oxidation fan to squeeze into ammonium salt oxidation tank bottom become ammonium sulfate with the sulfite oxidation in the solution, and deliver to the drying system that links to each other with the ammonium salt oxidation tank and carry out drying, obtain the desulfurizing byproduct ammonium sulfate fertilizer, realized the conversion of sulphur resources effective, reduced pollution environment.
Desulfurizing tower is in to flue gas desulfurization, the a small amount of flue dust that also contains in the flue gas can also be removed, through operation after a while, these flue dust can be accumulated in the desulfurizing tower bottom, normal operation to desulfurizing tower impacts, ammonia method desulfurizing method of the present invention adopts the liquid that partially absorbs that regularly will deposit most of dust from the desulfurizing tower bottom to be expelled to outside the tower certainly, utilize the accident solution pool of system, carry out sedimentation separation, will return pump by accident solution through the supernatant of sedimentation again and return and can be used as absorption liquid again behind the solution pool at the bottom of the desulfurization Tata and continue to absorb.The accident solution pool also can be used as the temporary transient storing place of absorption liquid in the tower when desulphurization system fault or maintenance, when desulphurization system was resumed operation, accident solution returns pump can return absorption liquid continuation use in the tower.Can guarantee that by this method of operation desulfurizing tower can not be subjected to the interference of dust in long-time, the tower deashing of needn't stopping transport out, and guaranteed that the purity of final accessory substance and quality can not be subjected to effect of dust.
The new method that absorbs ammonia process of the present invention adopts tower external oxidation ammonium sulfite, prevent oxidation in the tower, in case the content of ammonium sulfite in the minimizing solution, ammonium sulfite is the main absorber that absorbs sulfide in the flue gas, in case reduce, will influence the desulfurization degree of whole system, if in order to guarantee desulfurization degree, add excess of ammonia, ease ammonia in the outlet flue gas is exceeded standard, so in order to guarantee the ammonia-spillage amount in the strict simultaneously control outlet of the desulfurization degree flue gas, the present invention will reach certain density solution discharge tower and carry out oxidation outward, deliver to drying system again and be dried to ammonium sulfate fertilizer.
For solution pool at the bottom of the tower, when the densimeter detection ammonium salt solution concentration of solution pool reached 15%-40%, discharge pipe 10 drained into the ammonium salt oxidation tank with the part solution of solution pool at the bottom of the tower.Described ammonium salt is ammonium sulfite and ammonium bisulfite.
Regularly discharge and carry out sedimentation and handle from fall the highest solution of bottom dustiness from comb dust every day of desulfurizing tower bottom deposit, and then the supernatant after the sedimentation is returned solution pool at the bottom of the tower by pump.
The amount of injecting ammonia from annotate the ammonia pipe is to control according to the pH value of solution in the desulfurizing tower and the monitor value of desulfurizing tower inlet flue gas sulfide, ammonium bisulfite in the solution can be reduced into the amount of ammonium sulfite, can be more excessive, concrete feeding amount can detect by the flowmeter of annotating on the ammonia pipe.
The detection of solution pool and all be prior art at the bottom of the tower of the present invention according to the Monitoring and Controlling technology of sulfide in the pH value of solution in the desulfurizing tower and the desulfurizing tower inlet flue gas.
Beneficial effect of the present invention is: adopt method and apparatus of the present invention that boiler smoke is carried out desulfurization, the desulfurization degree of outlet flue gas can reach more than 98%, adopting method of the present invention and device that flue gas is carried out desulfurization handles, because before after absorbing by the column plate layer, entering demister at flue gas, entering the secondary spray section absorbs, therefore this method has reduced ammonia and the ammonium sulfate and the aerocolloidal content of ammonium sulfite of overflowing in the outlet flue gas when having improved desulfurization degree, has avoided secondary pollution.What use in the middle of the conventional method is oxidation in the tower, therefore the ammonia that feeds in the desulfurizing tower absorbs the sulfide in the flue gas as absorbent at last, rather than ammonium sulfite absorbs the sulfide in the flue gas, thereby caused the amount of effusion ammonia in the outlet flue gas to exceed standard, thereby caused secondary pollution, but, for the present invention, since the ammonia that feeds in the solution pool at the bottom of the tower in the method for the present invention with tower at the bottom of ammonium bisulfite in the solution pool be reduced into ammonium sulfite, feeding amount control to ammonia is very strict, and method employing of the present invention is outside tower sulfite oxidation to be become byproduct of ammonium sulfate, so guaranteeing under the prerequisite that the absorption liquid absorbability does not descend, the ammonia amount of overflowing in the outlet flue gas has also obtained effective control.Because the desulfurizing tower bottom deposit has partially absorbing in the accident solution pool of liquid outside discharge pipe is discharged tower of most of dust in the method for the present invention, it is carried out sedimentation separation, to return in the desulfurizing tower by pump through the supernatant of sedimentation separation again and continue to absorb as absorption liquid, the mud of sedimentation can be discharged by sludge pump, so method of the present invention and device can guarantee desulfurizing tower and can not be subjected to the interference of dust in long-time, the tower deashing of needn't stopping transport out, and guaranteed that the purity of final accessory substance and quality can not be subjected to effect of dust.
The specific embodiment
Embodiment 1
A kind of desulfurizing tower 7, the solution pool 8, one-level spray section 2, column plate layer 3, the secondary spray section 4 that comprise the desulfurizing tower bottom from the bottom to top, wherein one-level spray section 2 comprises 1-3 layer spray equipment, column plate layer 3 comprises 1-2 layer column plate, demister 5 is equipped with in secondary spray section 4 tops, links to each other with the top exhanst gas outlet 6 of desulfurizing tower; Below the middle departmental level spray section 2 of desulfurizing tower, be provided with smoke inlet 1; The side of the solution pool 8 of described desulfurizing tower bottom links to each other with notes ammonia pipe 9; Be outside equipped with three circulating pumps 11 at tower, the outlet of above-mentioned circulating pump 11 links to each other with one-level spray section 2, column plate layer 3, secondary spray section 4 respectively, and above-mentioned inlet of circulating pump links to each other with the solution pool 8 of desulfurizing tower bottom respectively.
The bottom in the bottom solution pond 8 of desulfurizing tower links to each other with ammonium salt oxidation tank 13 by excavationg pump 12; Wherein the import of excavationg pump 12 links to each other with the discharge pipe 10 that is positioned at desulfurizing tower solution pool 8 belows, and outlet links to each other with the top of ammonium salt oxidation tank 13; The below of ammonium salt oxidation tank 13 links to each other with oxidation fan 15, also is provided with ammonium salt discharge pipe 14 at the middle part of ammonium salt oxidation tank 13.
Desulfurizing tower bottom links to each other by the top of the accident solution pool 17 outside comb 19 and tower of desulfurizing tower, one side of the below of accident solution pool 17 links to each other with sludge pump 18, the import that accident solution returns pump 16 links to each other with accident solution pool 17, and the outlet that accident solution returns pump 16 links to each other with desulfurizing tower solution pool 8.
Embodiment 2
Remainder is identical in embodiment 1, contains the cooling heat exchanger on the difference smoke inlet passage.
Embodiment 3
To be 120 ℃ flue gas 1 * 10 from the temperature of boiler
4Standard cubic meter/hour enter desulfurizing tower 7 from gas approach 1, wherein sulfur-containing oxide is 1600ppm in the flue gas, at first be cooled to 65-70 ℃ through one-level spray section 2, and there is the partial vulcanization thing to be absorbed, flue gas is by containing the column plate layer of 1 layer of column plate then, the liquid film that flows on the column plate is when flue gas passes through, carried out sufficient reaction with flue gas, the sulfide of the overwhelming majority in the flue gas is removed, flue gas continues to rise again by secondary spray section 4 then, absorbed a small amount of ease ammonia that contains in the flue gas, the absorption liquid of described spray section and column plate layer is 30% ammonium salt solution, during the demister 5 of the flue gas of carrying the ammonium sulfite drop at last secretly by top of tower, the ammonium sulfate drop of carrying secretly in the flue gas is all tackled by demister, and last clean flue gas is gone out by exhanst gas outlet 6.Solution that spraying layer and column plate fall further concentrates through absorbing the back, deposits at last and gets back to solution pool 8 at the bottom of the tower, injects ammonia (with NH by ammonia ascending pipe 9 again
3Meter) 23.8 kilograms/hour, be reduced into ammonium sulfite with absorbing the ammonium bisulfite that generates behind the sulfide, solution circulation pump 11 is delivered to spraying layer and column plate respectively with the absorption liquid ammonium sulfite, absorbs the sulfide in the flue gas.
The solution of solution pool drains into ammonium salt oxidation tank 13 regularly from discharge pipe 10 by excavationg pump 12 at the bottom of the tower, is oxidized to ammonium sulfate at this ammonium sulfite by air or oxygen, drains into drying system by ammonium salt discharge pipe 14 again, is dried to ammonium sulfate fertilizer, or is used to make composite fertilizer.
The solution that dust content is high in the desulfurizing tower carries out sedimentation separation from the desulfurizing tower bottom in comb 19 is expelled to accident solution pool 17, supernatant returns pump 16 by accident solution and returns continuation use in the tower.The mud of accident solution pool bottom carries out by sludge pump 18.
Embodiment 4
To be 160 ℃ flue gas 1.2 * 10 from the temperature of boiler
6Standard cubic meter/hour be cooled to 100 ℃ to enter desulfurizing tower 7 from gas approach 1 through the cooling heat exchanger, wherein sulfur-containing oxide is 600ppm in the flue gas, at first be cooled to 65 ℃ through one-level spray section 2, and there is the partial vulcanization thing to be absorbed, flue gas is by containing the column plate layer of 2 layers of column plate then, the liquid film that flows on the column plate is when flue gas passes through, carried out sufficient reaction with flue gas, the sulfide of the overwhelming majority in the flue gas is removed, flue gas continues to rise again by secondary spray section 4 then, absorbed a small amount of ease ammonia that contains in the flue gas, the absorption liquid of described spray section and column plate layer is 40% ammonium salt solution, during the demister 5 of the flue gas of carrying the ammonium sulfite drop at last secretly by top of tower, the ammonium sulfate drop of carrying secretly in the flue gas is all tackled by demister, and last clean flue gas is gone out by exhanst gas outlet 6.Solution that spraying layer and column plate fall further concentrates through absorbing the back, deposits at last and gets back to solution pool 8 at the bottom of the tower, injects ammonia (with NH by ammonia ascending pipe 9 again
3Meter) 1071 kilograms/hour, be reduced into ammonium sulfite with absorbing the ammonium bisulfite that generates behind the sulfide, solution circulation pump 11 is delivered to spraying layer and column plate respectively with the absorption liquid ammonium sulfite, absorbs the sulfide in the flue gas.
The solution of solution pool drains into ammonium salt oxidation tank 13 regularly from discharge pipe 10 by excavationg pump 12 at the bottom of the tower, is oxidized to ammonium sulfate at this ammonium sulfite by air or oxygen, drains into drying system by ammonium salt discharge pipe 14 again, is dried to ammonium sulfate fertilizer, or is used to make composite fertilizer.
Desulfurizing tower includes the high solution of dust concentration and carries out sedimentation separation from the desulfurizing tower bottom in comb 19 is expelled to accident solution pool 17, and supernatant returns pump 16 by accident solution and returns continuation use in the tower.The mud of accident solution pool bottom carries out by sludge pump 18.
Embodiment 5
To be 140 ℃ flue gas 2 * 10 from the temperature of boiler
5Standard cubic meter/hour will lower the temperature enters desulfurizing tower 7 from gas approach 1 after heat exchanger is cooled to 80 ℃, wherein sulfur-containing oxide is 1000ppm in the flue gas, at first be cooled to 60 ℃ through the spray section 2 that contains 2 layers of spray equipment, and there is the partial vulcanization thing to be absorbed, flue gas is by containing the column plate layer of 1 layer of column plate then, the liquid film that flows on the column plate is when flue gas passes through, carried out sufficient reaction with flue gas, the sulfide of the overwhelming majority in the flue gas is removed, flue gas continues to rise again by secondary spray section 4 then, absorbed a small amount of ease ammonia that contains in the flue gas, the absorption liquid of described spray section and column plate layer is 20% ammonium salt solution, during the demister 5 of the flue gas of carrying the ammonium sulfite drop at last secretly by top of tower, the ammonium sulfate drop of carrying secretly in the flue gas is all tackled by demister, and last clean flue gas is gone out by exhanst gas outlet 6.Solution that spraying layer and column plate fall further concentrates through absorbing the back, deposits at last and gets back to solution pool 8 at the bottom of the tower, injects ammonia (with NH by ammonia ascending pipe 9 again
3Meter) 297.5 kilograms/hour, be reduced into ammonium sulfite with absorbing the ammonium bisulfite that generates behind the sulfide, solution circulation pump 11 is delivered to spraying layer and column plate respectively with the absorption liquid ammonium sulfite, absorbs the sulfide in the flue gas.
The solution of solution pool drains into ammonium salt oxidation tank 13 regularly from discharge pipe 10 by excavationg pump 12 at the bottom of the tower, is oxidized to ammonium sulfate at this ammonium sulfite by air or oxygen, drains into drying system by ammonium salt discharge pipe 14 again, is dried to ammonium sulfate fertilizer, or is used to make composite fertilizer.
Desulfurizing tower includes the high solution of dust concentration and carries out sedimentation separation from the desulfurizing tower bottom in comb 19 is expelled to accident solution pool 17, and supernatant returns pump 16 by accident solution and returns continuation use in the tower.The mud of accident solution pool bottom carries out by sludge pump 18.
Embodiment 6
To be 120 ℃ flue gas 3 * 10 from the temperature of boiler
4Standard cubic meter/hour enter desulfurizing tower 7 from gas approach 1, wherein sulfur-containing oxide is 800ppm in the flue gas, at first be cooled to 65-70 ℃ through one-level spray section 2, and there is the partial vulcanization thing to be absorbed, flue gas is by containing the column plate layer of 1 layer of column plate then, the liquid film that flows on the column plate is when flue gas passes through, carried out sufficient reaction with flue gas, the sulfide of the overwhelming majority in the flue gas is removed, flue gas continues to rise again by secondary spray section 4 then, absorbed a small amount of ease ammonia that contains in the flue gas, the absorption liquid of described spray section and column plate layer is 10% ammonium salt solution, during the demister 5 of the flue gas of carrying the ammonium sulfite drop at last secretly by top of tower, the ammonium sulfate drop of carrying secretly in the flue gas is all tackled by demister, and last clean flue gas is gone out by exhanst gas outlet 6.Solution that spraying layer and column plate fall further concentrates through absorbing the back, deposits at last and gets back to solution pool 8 at the bottom of the tower, injects ammonia (with NH by ammonia ascending pipe 9 again
3Meter) 35.7 kilograms/hour, be reduced into ammonium sulfite with absorbing the ammonium bisulfite that generates behind the sulfide, solution circulation pump 11 is delivered to spraying layer and column plate respectively with the absorption liquid ammonium sulfite, absorbs the sulfide in the flue gas.
The solution of solution pool drains into ammonium salt oxidation tank 13 regularly from discharge pipe 10 by excavationg pump 12 at the bottom of the tower, is oxidized to ammonium sulfate at this ammonium sulfite by air or oxygen, drains into drying system by dry discharge pipe 14 again, is dried to ammonium sulfate fertilizer, or is used to make composite fertilizer.
Desulfurizing tower includes the high solution of dust concentration and carries out sedimentation separation from the desulfurizing tower bottom in comb 19 is expelled to accident solution pool 17, and supernatant returns pump 16 by accident solution and returns continuation use in the tower.The mud of accident solution pool bottom carries out by sludge pump 18.