CN211411611U

CN211411611U - Three-stage desulfurization recovery structure of flue gas desulfurization equipment

Info

Publication number: CN211411611U
Application number: CN201921690132.6U
Authority: CN
Inventors: 刘攀; 周伟军; 张跃华; 黄华军
Original assignee: Hunan Tianyi Environmental Protection Tec Co ltd
Current assignee: Hunan Tianyi Environmental Protection Tec Co ltd
Priority date: 2019-10-11
Filing date: 2019-10-11
Publication date: 2020-09-04
Anticipated expiration: 2029-10-11

Abstract

The utility model provides a tertiary desulfurization recovery structure of flue gas desulfurization equipment, include: pneumatic emulsification absorbs storehouse (10), mixer (11), first order circulation pond (12), aeration equipment (13), second level absorbs storehouse (14), second level circulation pond (15), third level absorbs storehouse (16), third level circulation pond (17), the flue gas gets into second level and absorbs storehouse (14) and is sprayed the processing after pneumatic emulsification absorbs storehouse (10) is handled, then get into third level and absorb storehouse (16) and be sprayed the processing once more, form the gypsum through aeration oxidation after pneumatic emulsification absorbs storehouse discharge liquid gets into first level circulation pond (12), slurrying pond (18), third level circulation pond (17), second level circulation pond (15), first level circulation pond (12) adopt linker principle connecting tube in proper order.

Description

Three-stage desulfurization recovery structure of flue gas desulfurization equipment

Technical Field

The utility model belongs to the technical field of flue gas desulfurization, especially limestone-gypsum method desulfurization specifically is a multistage absorption, tertiary desulfurization recovery structure of limestone-gypsum method flue gas desulfurization equipment of independent circulation.

Background

The high-sulfur waste gas is a main atmospheric pollutant discharged in the non-ferrous metal smelting process, which always troubles the development of the non-ferrous metal industry, and the existing desulfurization technology is used for dust removal and desulfurization of a non-ferrous metal smelting kiln, and has the following main problems: 1) the treatment effect is unstable, the standard discharge is difficult to achieve, and the dual purposes of gypsum formation are achieved, the reaction conditions required by the absorption of sulfur dioxide and the formation of gypsum are contradictory, the more alkaline the environment required by the absorption of sulfur dioxide is, the better the pH environment required by the formation of gypsum is than the pH environment required by the absorption of sulfur dioxide; 2) the traditional limestone-gypsum desulfurization process is relatively complex, has more infrastructure, contains a large amount of flue gas pipelines, desulfurization towers and circulating pools, occupies a large area and has high one-time investment cost; 3) the desulfurization efficiency of the traditional spraying method is low, and only one circulating tank is arranged, so that in order to ensure that the desulfurization index reaches the standard, under the condition that the desulfurizer (limestone powder slurry) is not used up, new desulfurizer slurry is supplemented to the circulating tank, and meanwhile, the original slurry is discharged, so that the operation cost of a desulfurization system is increased; 4) because the utilization rate of the desulfurizer is not high, the desulfurized gypsum product which can be effectively utilized is difficult to form, a large amount of desulfurized waste residue is generated, the water content of the desulfurized waste residue is high, the desulfurized waste residue is difficult to dehydrate, and if the heavy metal in the desulfurized waste residue exceeds the standard, the desulfurized waste residue can be identified as dangerous solid waste and is difficult to dispose.

The application is improved and optimized on the basis of the original patent application CN201821181472.1 of the applicant, and solves the following problems: 1) the original design of the inclined plate can prevent scaling and homogenize air, but regular water washing is needed, and the water washing process is avoided by designing the inclined plate into a replaceable structure; 2) the first-stage absorption bin is improved into pneumatic emulsification desulfurization, the desulfurization effect is improved, the pneumatic emulsification desulfurization tower is one of the most advanced devices currently used for industrial boiler desulfurization, and the pneumatic emulsification desulfurization tower has obvious advantages in the aspects of reliability, liquid-gas ratio, desulfurization rate, wear resistance, high temperature resistance, corrosion resistance, scale prevention, blockage prevention, flue gas water prevention and energy conservation; 3) a more reasonable communication structure is adopted among the three-stage circulation tanks, so that the absorbed sulfur can be converted into gypsum, and the circulation tanks are kept clean; 4) improving the arrangement of an aeration system for gypsum formation; 5) the washing tank and the washing bin adopt a circulating water structure, and the recovered water also enters the circulating system after gypsum vacuum dehydration without discharging waste water; 6) the structure of multi-stage absorption and independent circulation is still kept; 7) the equipment has reasonable overall performance, high sulfur removal efficiency and convenient system management.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a desulfurizer of flue gas desulfurization equipment supplyes the structure, forms a closed circulation, improves desulfurization efficiency.

The utility model discloses a solve the technical scheme that technical problem that exists among the well-known technique took and be: a three-stage desulfurization recovery structure of a flue gas desulfurization apparatus, comprising: the device comprises a pneumatic emulsification absorption bin (10), a stirrer (11), a first-stage circulation tank (12), an aeration device (13), a second-stage absorption bin (14), a second-stage circulation tank (15), a third-stage absorption bin (16) and a third-stage circulation tank (17), wherein flue gas is treated by the pneumatic emulsification absorption bin (10), enters the second-stage absorption bin (14) to be sprayed, then enters the third-stage absorption bin (16) to be sprayed again, a pneumatic emulsification absorption bin water outlet (105) introduces exhaust liquid absorbing sulfur into the lower part of the first-stage circulation tank (12), the exhaust liquid enters the first-stage circulation tank (12) to form gypsum through aeration oxidation, and the slurrying tank (18), the third-stage circulation tank (17), the second-stage circulation tank (15) and the first-stage circulation tank (12) are sequentially connected with a communicating vessel principle for supplementing a desulfurizing agent, and the third-stage circulation tank (17), The calcium sulfite in the second-stage circulating tank (15) finally enters the first-stage circulating tank (12), and is aerated and oxidized in the first-stage circulating tank (12) to form gypsum.

Further, the three-stage desulfurization recovery structure of a flue gas desulfurization apparatus, the aeration device (13) comprises: the aeration pipe comprises a first layer of aeration pipe (131), a second layer of aeration pipe (132), aeration holes (133) and a fan (134), wherein the aeration pipes are arranged in two layers at the lower part of the first-stage circulation tank (12), the stirring blade (111) of the stirrer (11) is arranged between the two layers of aeration pipes, and the aeration holes (133) are formed in one side of the two layers of aeration pipes, which faces the stirring blade (111).

Further, the three-stage desulfurization recovery structure of the flue gas desulfurization equipment is characterized in that two rows of the stirrer (11) are respectively arranged in the slurrying tank (18), the third-stage circulating tank (17), the second-stage circulating tank (15) and the first-stage circulating tank (12), the water outlet (105) of the pneumatic emulsification absorption bin is higher than the first-layer aeration pipeline (131), gypsum formed after aeration is discharged through the first-stage circulating tank discharge port (121), and the first-stage circulating tank discharge port (121) is positioned at the bottom of the first-stage circulating tank (12) and is connected with a pipeline after a section of conical closing in. .

Further, the three-stage desulfurization recovery structure of the flue gas desulfurization equipment comprises, in the pneumatic emulsification absorption bin (10): the device comprises a gas homogenizing chamber (101), a pneumatic emulsifier (102), an emulsion layer (103), a spray chamber (104), a spray head (08), an inclined plate (06) and a pneumatic emulsification absorption bin water outlet (105), wherein flue gas enters the pneumatic emulsifier (102) through the gas homogenizing chamber (101) after entering the pneumatic emulsification absorption bin (10) from the lower part, the pneumatic emulsifier (102) rotates at a high speed to drive the flue gas to rotate, a desulfurizer sprayed by the spray head (08) forms the emulsion layer (103) above the pneumatic emulsifier (102) under the rotary cutting of the flue gas, the flue gas and the desulfurizer fully react and absorb, then the purified flue gas upwards enters a smoke guide pipe (09) through the spray chamber (104) and the inclined plate (06) to enter a next-stage absorption bin, the emulsion absorbing sulfur falls downwards into the pneumatic emulsification absorption bin water outlet (105) due to thickening of the liquid layer and falls into a first-stage circulation tank (12), the absorption bin positions where the pneumatic emulsifier (102) and the emulsion layer (103) are located are inwards contracted, the spray head (08) obtains the desulfurizer from the upper layer of the first-stage circulation tank (12) through the pump (03) and the water pipe (07).

Further, according to the three-stage desulfurization recovery structure of the flue gas desulfurization equipment, gypsum is discharged from the first-stage circulation tank (12) and swirled through the gypsum cyclone (20), the gypsum is discharged from the bottom flow port (201) into the vacuum belt dehydrator (21), and overflow liquid flows back to the first-stage circulation tank (12) through the overflow port (202) and the overflow pipeline (203).

Furthermore, according to the three-stage desulfurization recovery structure of the flue gas desulfurization equipment, gypsum is dehydrated on the vacuum belt dehydrator (21), and filtered water generated by the dehydrating vacuum pipe (211) returns to the recovery water tank (22) from the recovered water inlet (221) through the filtrate collecting pipe (212) and the filtrate recovery pipe (213) for recycling.

The utility model has the advantages that: the utility model discloses an absorbing device of tertiary design adopts the method desulfurization that pneumatic emulsification and sprayed respectively to with pneumatic emulsification setting at the desulfurization of first order, arrange second, tertiary desulfurated liquid into first order circulation pond and carry out the aeration, structural design is reasonable, improves desulfurization effect.

Drawings

FIG. 1 is a schematic structural view of a flue gas desulfurization apparatus;

FIG. 2 is a schematic diagram of a sloping plate mounting structure of a flue gas desulfurization device;

FIG. 3 is a schematic view of a washing apparatus of a flue gas desulfurization apparatus;

FIG. 4 is a schematic structural view of a first-stage desulfurization unit of a flue gas desulfurization apparatus;

FIG. 5 is a schematic structural view of a three-stage desulfurization unit of a flue gas desulfurization apparatus;

description of the drawings: booster fan (01), washing bin (02), pump (03), washing water recovery tank (04), filter press (05), sloping plate (06), water pipe (07), spray head (08), smoke guide pipe (09), pneumatic emulsification absorption bin (10), stirrer (11), first stage circulation tank (12), aeration device (13), second stage absorption bin (14), second stage circulation tank (15), third stage absorption bin (16), third stage circulation tank (17), slurrying tank (18), desulfurizer pipeline (19), gypsum cyclone (20), vacuum belt dehydrator (21), recovery water tank (22), demisting bin (23), sloping plate mounting block (062), bin wall thickening plate (063), sealing ring (064), screw (065), smoke guide pipe inlet (091), washing bin water outlet (021), washing water circulation tank (022), sedimentation tank (041), overflow plate (042), A clear liquid tank (043), an air equalizing chamber (101), a pneumatic emulsifier (102), an emulsion layer (103), a spray chamber (104), a pneumatic emulsification absorption bin water outlet (105), a stirring blade (111), a first-stage circulation tank discharge port (121), a first-stage circulation tank desulfurizer inlet (122), a first-layer aeration pipeline (131), a second-layer aeration pipeline (132), an aeration hole (133), a fan (134) and a second-stage circulation tank discharge port (151), a third stage circulation pool discharge port (171), a slurrying pool discharge port (181), a bottom flow port (201), an overflow port (202), an overflow pipeline (203), a dewatering vacuum pipe (211), a filtrate collecting pipe (212), a filtrate recovery pipe (213), a recovered water inlet (221), a recovered water sedimentation pool (222), a recovered water overflow plate (223), a recovered water clear liquid pool (224), a demister (231) and a smoke outlet (232).

Detailed Description

The present invention will be further described with reference to the accompanying drawings so as to facilitate the understanding of the present invention by those skilled in the art.

As shown in fig. 1, a flue gas desulfurization apparatus includes: the device comprises a booster fan (01), a washing bin (02), a pump (03), a washing water recovery tank (04), a filter press (05), an inclined plate (06), a water pipe (07), a spray head (08), a smoke guide pipe (09), a pneumatic emulsification absorption bin (10), a stirrer (11), a first-stage circulation tank (12), an aeration device (13), a second-stage absorption bin (14), a second-stage circulation tank (15), a third-stage absorption bin (16), a third-stage circulation tank (17), a slurrying tank (18), a desulfurizer pipeline (19), a gypsum cyclone (20), a vacuum belt dehydrator (21), a recovery water tank (22) and a demisting bin (23); flue gas enters a washing bin (02) through a booster fan (01), the washing bin (02) is flushed through a spray head (08) to remove a large amount of smoke dust in the flue gas and cool the flue gas, loss caused by leakage of the smoke dust due to failure of a previous dust removal measure can be prevented, the hidden danger that the heavy metal content in subsequent gypsum exceeds the standard is removed, flushed washing water enters a washing water recovery tank (04), water in the washing water recovery tank (04) is pumped into a washing water circulation tank (022) through a filter press (05) after being precipitated, a pump (03) pumps water from the washing water circulation tank (022) and then the pumped water is sent to the spray head (08) through a water pipe (07) for use, and the flushed flue gas enters a pneumatic emulsification absorption bin (10) through a smoke guide pipe (09); the principle of the pneumatic emulsification absorption bin (10) is as follows: accelerated smoke to be treated enters a rotating circular tubular container from the lower end at a certain angle to form turbulent airflow, the turbulent airflow collides with a solution flowing down from the upper end of the container, the solution flowing down is cut in a rotary manner at a high speed, the gas and the liquid continuously collide with each other and are cut in a rotary manner, liquid particles are more and more thin, the gas and the liquid are fully mixed to form a stable emulsion layer (103) with a certain thickness and are gradually thickened, the emulsion formed at the earliest is replaced by the newly formed emulsion, and the trapped impurities are carried to fall to the bottom of a pneumatic emulsion absorption bin (10) and flow into a first-stage circulating pool (12); a stirrer (11) and an aeration device (13) are arranged in the first-stage circulating tank (12), a large amount of sulfur dioxide in the flue gas is absorbed by a desulfurizing agent (limestone slurry) to form calcium sulfite, and the calcium sulfite is oxidized into calcium sulfate through aeration forced oxidation to further form gypsum; the formed gypsum is sent to a gypsum cyclone (20) through a discharge pump for concentration, the concentrated gypsum slurry enters a vacuum belt dehydrator (21), the surface water content of the gypsum after dehydration treatment is not more than 10 percent, the dehydrated gypsum is stored in a gypsum warehouse for storage and transportation, the overflow liquid separated by the gypsum cyclone (20) returns to a first-stage circulation tank (12), the filtered water generated by gypsum dehydration is returned to a recovery water tank (22) for recycling, and the filtered water is completely collected for recycling without being discharged; the second-stage absorption bin (14) and the second-stage circulation tank (15), the third-stage absorption bin (16) and the third-stage circulation tank (17) form two-stage independent absorption circulation in the pneumatic emulsification absorption bin (10) and the first-stage circulation tank (12), flue gas after three-stage absorption is discharged after demisting in a demisting bin (23), the three-stage circulation tanks are communicated with each other through a desulfurizer pipeline (19), the third-stage circulation tank (17) is communicated with a slurrying tank (18), and water generated by the demisting bin (23) enters a recovery water tank (22).

As shown in fig. 2, an inclined plate mounting structure of a flue gas desulfurization device, wherein an inclined plate (06) is mounted above a spray head (08) of a washing bin (02), a pneumatic emulsification absorption bin (10), a second-stage absorption bin (14) and a third-stage absorption bin (16) and below a smoke guide pipe inlet (091), the inclined plate mounting structure comprises: the cleaning device comprises a sloping plate (06), a sloping plate mounting block (062), a bin wall thickening plate (063), a sealing ring (064) and a screw (065), wherein the sloping plate (06) is clamped on the sloping plate mounting block (062), the bin wall thickening plate (063) is welded on the outer side of the bin wall, the bin wall thickening plate (063) is provided with a sealing ring mounting groove and a screw mounting hole, the sloping plate mounting block (062) is mounted on the bin wall thickening plate (063) by screwing the screw (065) after the sealing ring (064) is pressed in, the sloping plate (06) is inserted into the bin, the bin bodies of the washing bin (02), the pneumatic emulsification absorption bin (10), the second-stage absorption bin (14) and the third-stage absorption bin (16) are preferably square, the sloping plate (06) can be inserted from one side, and can also be round, only the sloping plate (06) is required to be blocked under a smoke guide inlet (091), and the sloping plate (06) is inserted from one side close to, the other side of the smoke guide pipe is tilted upwards to form an inclination, the smoke guide pipe inlet (091) extends into the bin for a certain distance, and the scale can be prevented by a method of removing the inclined plate (06) for replacement after a certain time.

As shown in fig. 3, a washing device of a flue gas desulfurization apparatus includes: booster fan (01), washing storehouse (02), pump (03), washing water recovery pond (04), pressure filter (05), swash plate (06), water pipe (07), shower nozzle (08), lead tobacco pipe (09), the flue gas passes through booster fan (01) and gets into washing storehouse (02), wash through shower nozzle (08) in washing storehouse (02), get rid of a large amount of smoke and dust in the flue gas and cool down the flue gas, washing water after the washing gets into washing water recovery pond (04) through washing storehouse delivery port (021), washing water recovery pond (04) include: sedimentation tank (041), overflow plate (042), clear solution pond (043), the washing water overflows to clear solution pond (043) after deposiing, the water in clear solution pond (043) is by pressure filter (05) suction washing water circulation pond (022), use pump (03) to draw water from washing water circulation pond (022) and send shower nozzle (08) to use through water pipe (07), the flue gas after the washing is after swash plate (06) is even gas, get into pneumatic emulsification absorption storehouse (10) by leading tobacco pipe (09), for reinforcing washing effect, the shower nozzle (08) arranges the three-layer.

As shown in fig. 4, a first-stage desulfurization device of a flue gas desulfurization apparatus includes: pneumatic emulsification absorbs storehouse (10), mixer (11), first order circulation pond (12), aeration equipment (13), include in pneumatic emulsification absorbs the storehouse (10): the device comprises a gas homogenizing chamber (101), a pneumatic emulsifier (102), an emulsion layer (103), a spray chamber (104), a spray head (08), an inclined plate (06) and a pneumatic emulsification absorption bin water outlet (105), wherein flue gas enters the pneumatic emulsifier (102) through the gas homogenizing chamber (101) after entering the pneumatic emulsification absorption bin (10) from the lower part, the pneumatic emulsifier (102) rotates at a high speed to drive the flue gas to rotate, a desulfurizer sprayed by the spray head (08) forms the emulsion layer (103) above the pneumatic emulsifier (102) under the rotary cutting of the flue gas, the flue gas and the desulfurizer fully react and absorb, then the purified flue gas upwards enters a smoke guide pipe (09) through the spray chamber (104) and the inclined plate (06) to enter a next-stage absorption bin, the emulsion absorbing sulfur falls downwards into the pneumatic emulsification absorption bin water outlet (105) due to thickening of the liquid layer and falls into a first-stage circulation tank (12), the absorption bin positions where the pneumatic emulsifier (102) and the emulsion layer (103) are located are inwards contracted, the spray head (08) obtains the desulfurizer from the upper layer of the first-stage circulation tank (12) through the pump (03) and the water pipe (07), the pneumatic emulsification absorption bin water outlet (105) leads the discharged liquid absorbed with sulfur to the lower part of the first-stage circulation tank (12), the discharged liquid is required to be oxidized through aeration to form gypsum after entering the first-stage circulation tank (12), and the aeration device (13) comprises: first layer aeration pipe (131), second floor aeration pipe (132), aeration hole (133), fan (134), the aeration pipe is arranged two-layerly in first order circulation pond (12) lower part, and stirring leaf (111) of mixer (11) set up between two-layer aeration pipe, and aeration hole (133) are seted up towards one side of stirring leaf (111) to two-layer aeration pipe, mixer (11) set up two, pneumatic emulsification absorption storehouse delivery port (105) are higher than first layer aeration pipe (131), and the aeration is sunk to the calcium sulfite, and the gypsum that forms after the aeration discharges through first order circulation pond discharge port (121), and first order circulation pond discharge port (121) are located first order circulation pond (12) bottom and through connecting tube behind one section toper binding off.

As shown in fig. 5, a three-stage desulfurization device of a flue gas desulfurization apparatus includes: the device comprises a pneumatic emulsification absorption bin (10), a stirrer (11), a first-stage circulation tank (12), an aeration device (13), a second-stage absorption bin (14), a second-stage circulation tank (15), a third-stage absorption bin (16) and a third-stage circulation tank (17), wherein flue gas is treated by the pneumatic emulsification absorption bin (10), enters the second-stage absorption bin (14) to be sprayed, then enters the third-stage absorption bin (16) to be sprayed again, the flue gas is good in purification effect, then enters a demisting bin (23) to be demisted by a demister (231) and then is discharged from a smoke outlet (232), in the aspect of recycling of water, gypsum is discharged from the first-stage circulation tank (12) and is swirled by a gypsum swirler (20), the gypsum is discharged into a vacuum belt dehydrator (21) from a bottom flow port (201), overflow liquid returns to the first-stage circulation tank (12) through an overflow port (202) and an overflow pipeline (203), and the gypsum is dehydrated on the vacuum belt dehydrator (21), filtered water generated by a dehydrating vacuum tube (211) returns to a recovery water tank (22) through a filtrate collecting pipe (212) and a filtrate recovery pipe (213) through a recovered water inlet (221) for recycling, the filtered water is completely collected and recycled without being discharged outside, a mechanism for supplementing the desulfurizer in a first-stage circulation tank (12), a second-stage circulation tank (15) and a third-stage circulation tank (17) is that limestone slurry with the concentration of 16-20% is prepared as the desulfurizer in a slurrying tank (18) under the action of a stirrer (11) by quantitatively adding limestone powder, the desulfurizer is sent to the third-stage circulation tank (17) through a desulfurizing agent pipeline (19) through a slurrying tank discharge port (181) arranged at the bottom of the slurrying tank (18), reacted calcium sulfite sinks into a third-stage circulation tank discharge port (171), and under the action of the stirrer (11) and water pressure, the calcium sulfite is extruded into a desulfurizer pipeline (19) and enters a second-stage circulating pool (15), and similarly, the calcium sulfite finally enters a first-stage circulating pool (12), and is aerated and oxidized in the first-stage circulating pool (12) to form gypsum.

The above examples are only intended to illustrate the specific embodiments of the present invention, but not to limit the present invention, and it will be apparent to those skilled in the art that various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should be regarded as the protection scope of the present invention.

Claims

1. A three-stage desulfurization recovery structure of a flue gas desulfurization apparatus, comprising: the device comprises a pneumatic emulsification absorption bin (10), a stirrer (11), a first-stage circulation tank (12), an aeration device (13), a second-stage absorption bin (14), a second-stage circulation tank (15), a third-stage absorption bin (16) and a third-stage circulation tank (17), wherein flue gas is treated by the pneumatic emulsification absorption bin (10), enters the second-stage absorption bin (14) to be sprayed, then enters the third-stage absorption bin (16) to be sprayed again, a pneumatic emulsification absorption bin water outlet (105) introduces exhaust liquid absorbing sulfur into the lower part of the first-stage circulation tank (12), the exhaust liquid enters the first-stage circulation tank (12) to form gypsum through aeration oxidation, and the slurrying tank (18), the third-stage circulation tank (17), the second-stage circulation tank (15) and the first-stage circulation tank (12) are sequentially connected with a communicating vessel principle for supplementing a desulfurizing agent, and the third-stage circulation tank (17), The calcium sulfite in the second-stage circulating tank (15) finally enters the first-stage circulating tank (12), and is aerated and oxidized in the first-stage circulating tank (12) to form gypsum.

2. The three-stage desulfurization recovery structure of a flue gas desulfurization apparatus according to claim 1, characterized in that the aeration device (13) comprises: the aeration pipe comprises a first layer of aeration pipe (131), a second layer of aeration pipe (132), aeration holes (133) and a fan (134), wherein the aeration pipes are arranged in two layers at the lower part of the first-stage circulation tank (12), the stirring blade (111) of the stirrer (11) is arranged between the two layers of aeration pipes, and the aeration holes (133) are formed in one side of the two layers of aeration pipes, which faces the stirring blade (111).

3. The three-stage desulfurization recovery structure of flue gas desulfurization equipment according to claim 2, wherein the stirrer (11) is arranged in two rows in the slurrying tank (18), the third stage circulation tank (17), the second stage circulation tank (15) and the first stage circulation tank (12), the water outlet (105) of the pneumatic emulsification absorption bin is higher than the first layer aeration pipeline (131), the gypsum formed after aeration is discharged through the first stage circulation tank discharge outlet (121), and the first stage circulation tank discharge outlet (121) is positioned at the bottom of the first stage circulation tank (12) and is connected with the pipeline after being closed by a section of cone.

4. The three-stage desulfurization recovery structure of flue gas desulfurization equipment according to claim 1, wherein said pneumatic emulsification absorption bin (10) comprises therein: the device comprises a gas homogenizing chamber (101), a pneumatic emulsifier (102), an emulsion layer (103), a spray chamber (104), a spray head (08), an inclined plate (06) and a pneumatic emulsification absorption bin water outlet (105), wherein flue gas enters the pneumatic emulsifier (102) through the gas homogenizing chamber (101) after entering the pneumatic emulsification absorption bin (10) from the lower part, the pneumatic emulsifier (102) rotates at a high speed to drive the flue gas to rotate, a desulfurizer sprayed by the spray head (08) forms the emulsion layer (103) above the pneumatic emulsifier (102) under the rotary cutting of the flue gas, the flue gas and the desulfurizer fully react and absorb, then the purified flue gas upwards enters a smoke guide pipe (09) through the spray chamber (104) and the inclined plate (06) to enter a next-stage absorption bin, the emulsion absorbing sulfur falls downwards into the pneumatic emulsification absorption bin water outlet (105) due to thickening of the liquid layer and falls into a first-stage circulation tank (12), the absorption bin positions where the pneumatic emulsifier (102) and the emulsion layer (103) are located are inwards contracted, the spray head (08) obtains the desulfurizer from the upper layer of the first-stage circulation tank (12) through the pump (03) and the water pipe (07).

5. The three-stage desulfurization recovery structure of flue gas desulfurization equipment according to claim 1, wherein gypsum is discharged from the first-stage circulation tank (12) and swirled by a gypsum cyclone (20), gypsum is discharged from the underflow port (201) into the vacuum belt dehydrator (21), and the overflow liquid is returned to the first-stage circulation tank (12) through the overflow port (202) and the overflow pipe (203).

6. The three-stage desulfurization recovery structure of flue gas desulfurization equipment according to claim 5, wherein gypsum is dehydrated on a vacuum belt dehydrator (21), and the filtered water produced by the dehydrating vacuum tube (211) is returned to the recovery water tank (22) for recycling through the recovered water inlet (221) via the filtrate collecting pipe (212) and the filtrate recovery pipe (213).