Anticorrosion treatment equipment for phosphogypsum decomposition tail gas

Abstract

The utility model discloses ardealite decomposition tail gas anti-corrosion treatment equipment which comprises a decomposition kiln, a dust removal mechanism, an absorption tower and a tail gas treatment mechanism, a flue gas pipe extending to an inlet of the dust removal mechanism is arranged at the top end of the decomposition kiln, and a heat exchange pipe is sleeved outside the flue gas pipe. A hot air pipe extending to one side of the decomposition kiln is arranged at one end, close to the decomposition kiln, of the heat exchange pipe, an air inlet is formed in the other end of the heat exchange pipe, an absorption pipe is arranged between the dust removal mechanism and the absorption tower, and a tail gas pipe is arranged between the absorption tower and the tail gas treatment mechanism; the tail gas treatment mechanism comprises the following structures: an adsorption tank, the interior of the adsorption tank is hollow to form an adsorption cavity, the top of the adsorption cavity is provided with a purification pipe extending out of the adsorption tank, the bottom of the adsorption cavity is provided with a recovery pipe communicated with the tail gas pipe, the adsorption cavity is internally provided with a feeding worm extending from the top end to the bottom end, and one end of the feeding worm is provided with a driving motor; pollution hidden dangers existing in the ardealite decomposition acid-making process are effectively solved, and the environmental protection property of the ardealite decomposition acid-making process is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of phosphogypsum decomposition equipment, in particular to anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition. Background Art

[0002] Phosphogypsum is a solid industrial waste residue produced by wet phosphoric acid production. Phosphogypsum contains many harmful impurities such as phosphorus, fluorine and organic matter. Improper treatment methods can easily lead to environmental pollution. In addition, my country's sulfur resources are scarce and the demand for sulfuric acid is high. Phosphogypsum contains a large amount of CaSO4, which can be used to make sulfuric acid. 4 ·2H 2 O, phosphogypsum can be used as a renewable resource and effectively solve the hidden danger of environmental pollution. The process of decomposing phosphogypsum to produce sulfuric acid usually requires collecting sulfur dioxide produced by the decomposition of phosphogypsum and going through purification, oxidation and other steps. The sulfur dioxide and water vapor produced after the decomposition of phosphogypsum are easy to corrode the transmission pipeline, causing the transmission pipeline to be damaged and leading to sulfur dioxide leakage. At the same time, it is difficult for the equipment for collecting sulfur dioxide to completely collect all the sulfur dioxide. The uncollected sulfur dioxide and the impurity gas produced when the phosphogypsum is decomposed will form polluting tail gas. The polluting tail gas has the hidden danger of causing pollution to the environment. Therefore, in the process of decomposing phosphogypsum to produce sulfuric acid, it is necessary to prevent the corrosion of sulfur dioxide and treat the subsequent polluting tail gas to avoid environmental pollution. Utility Model Content

[0003] In view of the technical defects existing in the background technology, the utility model proposes a phosphogypsum decomposition tail gas anti-corrosion treatment equipment, which solves the above technical problems and meets the actual needs. The specific technical solution is as follows:

[0004] A phosphogypsum decomposition tail gas anti-corrosion treatment device, comprising a decomposition kiln, a dust removal mechanism, an absorption tower, and a tail gas treatment mechanism, wherein the top of the decomposition kiln is provided with a flue gas pipe extending to the inlet of the dust removal mechanism, the outer sleeve of the flue gas pipe is provided with a heat exchange pipe, one end of the heat exchange pipe close to the decomposition kiln is provided with a hot air pipe extending to one side of the decomposition kiln, and the other end is provided with an air inlet; the outlet of the dust removal mechanism is provided with an absorption pipe extending to the inlet of the absorption tower, and the outlet of the absorption tower is provided with a tail gas pipe extending to the inlet of the tail gas treatment mechanism;

[0005] The exhaust gas treatment mechanism includes the following structure: an adsorption tank, the interior of the adsorption tank is hollow to form an adsorption chamber, the top of the adsorption chamber is provided with a purification pipe extending out of the adsorption tank, the bottom of the adsorption chamber is provided with a recovery pipe connected to the exhaust pipe, the adsorption chamber is provided with a feeding worm extending from the top to the bottom, and one end of the feeding worm is provided with a driving motor.

[0006] As a further technical solution of the utility model, the internal shape of the adsorption chamber is cylindrical, and the feeding worm is composed of a shaft located on the axis of the adsorption chamber and spiral blades spirally wound along the shaft, and the outer edge of the spiral blades extends to the inner wall of the adsorption chamber.

[0007] As a further technical solution of the utility model, a storage hopper connected to the adsorption chamber is provided on the top of the adsorption tank, a feed port is provided on the top of the storage hopper, and a feed port cover matching the feed port is hinged on the top of the storage hopper through a hinge.

[0008] As a further technical solution of the utility model, a first dust-proof net is provided at one end of the tail gas pipe close to the recovery pipe, and a second dust-proof net is provided at one end of the purification pipe close to the adsorption chamber.

[0009] As a further technical solution of the utility model, a recovery hopper is provided at the bottom of the recovery pipe, a discharge port is provided at the bottom of the recovery hopper, and a discharge port cover matching the discharge port is hinged at the bottom of the recovery hopper through a hinge.

[0010] As a further technical solution of the utility model, a steam-water separator is provided on the flue gas pipe between the heat exchange tube and the dust removal mechanism.

[0011] As a further technical solution of the utility model, a plurality of first spoilers are arranged in the flue gas pipe, and a plurality of second spoilers are arranged in the heat exchange pipe.

[0012] As a further technical solution of the utility model, an anti-corrosion layer is provided on the inner wall of the absorption tube.

[0013] The beneficial effects of the utility model are:

[0014] The utility model exchanges heat between the flue gas generated after the decomposition of phosphogypsum in the decomposition kiln and the air through the heat exchange tube, reduces the temperature of the flue gas in the flue pipe, reduces the thermal corrosion and chemical corrosion of the flue gas to the dust removal mechanism and the pipeline, and avoids the environmental pollution caused by the leakage of flue gas due to the corrosion of the pipeline. The exhaust gas treatment mechanism can purify the harmful exhaust gas in the flue gas that has not been completely absorbed by the absorption tower through adsorption. The exhaust gas treatment mechanism maintains good activity of the activated carbon in the adsorption chamber through the feeding worm, so that the exhaust gas treatment mechanism maintains good purification efficiency for the exhaust gas, effectively solves the pollution hazards existing in the process of acid production by decomposition of phosphogypsum, and improves the environmental protection of the process of acid production by decomposition of phosphogypsum. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a structural schematic diagram of an anti-corrosion treatment device for tail gas from the decomposition of phosphogypsum.

[0016] Figure 2 The present invention is a structural schematic diagram of an exhaust gas treatment mechanism of an exhaust gas anti-corrosion treatment device for phosphogypsum decomposition.

[0017] Figure 3 yes Figure 1 Schematic diagram at A in the middle.

[0018] Figure 4 yes Figure 1 Schematic diagram of point B in the figure.

[0019] Among them: decomposition kiln 1, flue gas pipe 11, first spoiler 12, dust removal mechanism 2, absorption pipe 21, anti-corrosion layer 22, absorption tower 3, tail gas pipe 31, first dustproof net 32, tail gas treatment mechanism 4, adsorption tank 41, adsorption chamber 42, purification pipe 43, recovery pipe 44, feeding worm 45, drive motor 46, second dustproof net 47, heat exchange pipe 5, hot air pipe 51, air inlet 52, second spoiler 53, storage hopper 6, feed port 61, feed port cover 62, recovery hopper 7, discharge port 71, discharge port cover 72, steam-water separator 8. DETAILED DESCRIPTION

[0020] The implementation methods of the present invention are described below in conjunction with the accompanying drawings and relevant embodiments. The implementation methods of the present invention are not limited to the following embodiments, and the present invention involves relevant necessary components in this technical field, which should be regarded as common knowledge in this technical field and can be known and mastered by technical personnel in this technical field.

[0021] like Figure 1 , 2 As shown, a phosphogypsum decomposition tail gas anti-corrosion treatment equipment comprises a decomposition kiln 1, a dust removal mechanism 2, an absorption tower 3, and a tail gas treatment mechanism 4. The top of the decomposition kiln 1 is provided with a flue gas pipe 11 extending to the inlet of the dust removal mechanism 2, and the outer sleeve of the flue gas pipe 11 is provided with a heat exchange pipe 5. The heat exchange pipe 5 is provided with a hot air pipe 51 extending to one side of the decomposition kiln 1 at one end close to the decomposition kiln 1, and an air inlet 52 is provided at the other end; the outlet of the dust removal mechanism 2 is provided with an absorption pipe 21 extending to the inlet of the absorption tower 3, and the outlet of the absorption tower 3 is provided with a tail gas pipe 31 extending to the inlet of the tail gas treatment mechanism 4;

[0022] The exhaust gas treatment mechanism 4 includes the following structure: an adsorption tank 41, the interior of the adsorption tank 41 is hollow to form an adsorption chamber 42, the top of the adsorption chamber 42 is provided with a purification pipe 43 extending out of the adsorption tank 41, the bottom of the adsorption chamber 42 is provided with a recovery pipe 44 connected to the exhaust pipe 31, and the adsorption chamber 42 is provided with a feeding worm 45 extending from the top to the bottom, and a driving motor 46 is provided at one end of the feeding worm 45; the internal shape of the adsorption chamber 42 is cylindrical, and the feeding worm 45 is composed of a shaft located on the axis of the adsorption chamber 42 and a spiral blade spirally wound along the shaft, and the outer edge of the spiral blade extends to the inner wall of the adsorption chamber 42.

[0023] The decomposition kiln 1 of the utility model is provided with a container for containing phosphogypsum and a heating burner. The burner generates a large amount of heat by burning natural gas or other fuel gas to heat the phosphogypsum, so that the phosphogypsum is decomposed at high temperature to produce solid calcium oxide and flue gas containing gases such as sulfur dioxide, oxygen, carbon dioxide, water vapor, etc. The calcium oxide can be used to produce cement. The sulfur dioxide in the flue gas is separated by absorption, removal, purification and other steps to obtain sulfur dioxide with higher purity for making sulfuric acid. The flue gas generated after the decomposition of the phosphogypsum is discharged from the flue pipe 11. The flue gas carries a large amount of heat. In the process of the flue gas flowing to the dust removal mechanism 2 in the flue pipe 11, the flue gas exchanges heat with the air in the heat exchange pipe 5. The air in the heat exchange pipe 5 enters from the air inlet 52 and is completely After heat exchange, it enters the hot air pipe 51. The air in the hot air pipe 51 can be used as the combustion-supporting air necessary for burner combustion. The temperature of the combustion-supporting air increases after heat exchange, which can improve combustion efficiency and energy utilization efficiency. The flue gas pipe 11 is preferably made of ceramic material. Ceramic material has the advantages of high thermal conductivity, good corrosion resistance, and low thermal expansion coefficient. It can well conduct the heat in the flue gas to the combustion-supporting air in the heat exchange pipe 5, reduce the temperature of the flue gas, and reduce the thermal corrosion and chemical corrosion of the flue gas to the dust removal mechanism 2 and the pipeline. At the same time, the flue gas pipe 11 can well withstand the thermal corrosion and chemical corrosion of the flue gas, so that the flue gas can be transmitted stably, avoiding environmental pollution caused by smoke leakage due to pipeline corrosion.

[0024] The dust removal mechanism 2 preferably adopts a cyclone dust collector. The dust removal mechanism 2 can remove dust in the flue gas to prevent the dust from forming precipitation at the bottom of the absorption tower 3. The main component of these dusts is calcium oxide. A container for collecting dust can be set at the bottom of the dust removal mechanism 2, and the recovered dust can be used to produce cement; the dust-removed flue gas is transported to the absorption tower 3 through the absorption pipe 21. The absorption tower 3 is hollow and contains absorbents such as alkaline solutions. The end of the absorption pipe 21 extends into the absorbent, and the flue gas is discharged from the end of the absorption pipe 21 into the absorbent. Most of the sulfur dioxide in the flue gas will be absorbed by the absorbent. After absorbing the sulfur dioxide, the absorbent can be regenerated by heating or other means to release a high concentration of sulfur dioxide gas for the production of sulfuric acid. The part of the flue gas that is not absorbed will form exhaust gas and enter the exhaust pipe 31. The exhaust gas is transmitted to the exhaust gas treatment mechanism 4 through the exhaust pipe 31.

[0025] In the exhaust gas treatment mechanism 4, the adsorption chamber 42 of the adsorption tank 41 is filled with activated carbon and other materials that can adsorb harmful gases such as sulfur dioxide. The activated carbon is distributed in a spiral shape in the adsorption chamber 42 along the space between the spiral blades of the feeding worm 45. After the exhaust gas enters the adsorption chamber 42 from the bottom of the adsorption tank 41 at the end of the exhaust pipe 31, the exhaust gas flows in the adsorption chamber 42 along the spiral ascending direction of the activated carbon, which can extend the flow path and flow time of the exhaust gas in the adsorption chamber 42, so that the exhaust gas can fully contact with the activated carbon, so that the activated carbon can fully absorb the harmful gases in the exhaust gas, and purify the exhaust gas. The purified exhaust gas is mainly composed of oxygen and carbon dioxide. Then these exhaust gases leave the exhaust gas treatment mechanism 4 through the purification pipe 43. Some exhaust gas needs to be tested and found to meet the emission standards before it can be discharged, or this part of the exhaust gas is transmitted to the heat exchange tube 5 through a pipeline as combustion-supporting air for the burner combustion; because the exhaust gas first contacts the activated carbon at the bottom in the adsorption chamber 42, the activated carbon at the bottom will first reach the adsorption saturation state, and the feeding worm 45 can be driven by the driving motor 46 to rotate. When the feeding worm 45 rotates, the activated carbon on the top of the feeding worm 45 will enter the space between the spiral blades, and the adsorption saturated activated carbon at the bottom will be pushed to the recovery pipe 44 at the bottom of the feeding worm 45, and the adsorption saturated activated carbon will be recovered, so that the activated carbon around the feeding worm 45 maintains good activity, and the exhaust gas treatment mechanism 4 maintains a good purification efficiency for the exhaust gas.

[0026] The utility model exchanges heat between the flue gas generated after the decomposition of phosphogypsum in the decomposition kiln 1 and the air through the heat exchange tube 5, reduces the temperature of the flue gas in the flue pipe 11, reduces the thermal corrosion and chemical corrosion of the flue gas to the dust removal mechanism 2 and the pipeline, and avoids environmental pollution caused by the leakage of flue gas due to the corrosion of the pipeline. The exhaust gas treatment mechanism 4 can purify the harmful exhaust gas in the flue gas that has not been completely absorbed by the absorption tower 3 by adsorption. The exhaust gas treatment mechanism 4 maintains good activity of the activated carbon in the adsorption chamber 42 through the feeding worm 45, so that the exhaust gas treatment mechanism 4 maintains good purification efficiency for the exhaust gas, effectively solves the pollution risks existing in the process of decomposing phosphogypsum to make acid, and improves the environmental protection of the process.

[0027] like Figure 1 , 2 As shown, as one of the preferred embodiments of the utility model, a storage hopper 6 connected to the adsorption chamber 42 is provided on the top of the adsorption tank 41, a feed port 61 is provided on the top of the storage hopper 6, and a feed port cover 62 matching the feed port 61 is hinged on the top of the storage hopper 6 through a hinge.

[0028] The storage hopper 6 of the utility model is hollow inside and is used to hold activated carbon. When the driving motor 46 drives the feeding worm 45 to rotate, the activated carbon in the storage hopper 6 will enter the adsorption chamber 42 from the bottom to supplement the vacant activated carbon around the feeding worm 45. The storage hopper 6 can expand the capacity of the activated carbon in the exhaust gas treatment mechanism 4 and reduce the frequency of replacing the activated carbon in the exhaust gas treatment mechanism 4. The activated carbon in the storage hopper 6 can be added by opening the feed port cover 62, and the activated carbon with adsorption activity can be added through the feed port 61.

[0029] like Figure 1 , 2 As shown, as one of the preferred embodiments of the utility model, a first dustproof net 32 ​​is provided at one end of the tail gas pipe 31 close to the recovery pipe 44 , and a second dustproof net 47 is provided at one end of the purification pipe 43 close to the adsorption chamber 42 .

[0030] The first dust-proof net 32 ​​and the second dust-proof net 47 of the utility model both adopt dust-proof nets with a pore size smaller than the activated carbon particle size. The first dust-proof net 32 ​​of the tail gas pipe 31 near the recovery pipe 44 end can prevent the activated carbon in the recovery pipe 44 from entering the tail gas pipe, and at the same time does not affect the exhaust gas passing through the tail gas pipe 31 into the recovery pipe 44 and then entering the adsorption chamber 42 for purification; the second dust-proof net 47 of the purification pipe 43 near the adsorption chamber 42 end can prevent the activated carbon in the adsorption chamber 42 from entering the purification pipe 43, and at the same time does not affect the purified exhaust gas entering the purification pipe 43.

[0031] like Figure 1 As shown, as one of the preferred embodiments of the utility model, a recovery hopper 7 is provided at the bottom of the recovery pipe 44, a discharge port 71 is provided at the bottom of the recovery hopper 7, and a discharge port cover 72 matching the discharge port 71 is hinged at the bottom of the recovery hopper 7 through a hinge.

[0032] The recovery hopper 7 of the utility model is used to temporarily hold the recovered activated carbon, and the activated carbon is discharged from the discharge port 71 by opening the discharge port cover 72. The recovered activated carbon can recover the adsorbed sulfur dioxide therein by desorption, and the activated carbon with adsorption activity again can be added back to the exhaust gas treatment mechanism 4 to purify the exhaust gas; as a preferred embodiment, the capacity of the recovery hopper 7 is similar to that of the storage hopper 6. When the recovery hopper 7 is full of activated carbon, it means that the activated carbon in the storage hopper 6 needs to be added, so that the processes of adding and recovering activated carbon can be carried out at the same time node, thereby improving work efficiency.

[0033] like Figure 1 As shown, as one of the preferred embodiments of the utility model, a steam-water separator 8 is provided on the flue gas pipe 11 between the heat exchange tube 5 and the dust removal mechanism 2 .

[0034] The steam-water separator 8 of the utility model is used to separate water vapor in the flue gas. After the water vapor in the flue gas is separated, it enters the dust removal mechanism 2, which can prevent the dust removed by the dust removal mechanism 2 from containing too much water, thereby causing the dust to agglomerate or adhere to the inner wall of the dust removal mechanism 2.

[0035] like Figure 1 , 3 As shown, as one of the preferred embodiments of the utility model, a plurality of first spoilers 12 are provided in the flue gas pipe 11 , and a plurality of second spoilers 53 are provided in the heat exchange tube 5 .

[0036] The first spoiler 12 can be arranged in a spiral winding manner or staggered along the extension direction of the smoke pipe 11. The first spoiler 12 turbules the flow by blocking the flow of smoke, thereby extending the flow path and speed of the smoke, so that the smoke can more fully contact the inner wall of the smoke pipe 11, thereby improving the heat exchange efficiency between the smoke and the air; the second spoiler 53 can be staggered near the side of the outer surface of the smoke pipe 11 and near the side of the wall of the heat exchange tube 5, or can be arranged in a spiral winding manner along the extension direction of the heat exchange tube 5. The second spoiler 53 turbules the flow by blocking the flow of air inside the heat exchange tube 5, thereby extending the flow path and speed of the air, thereby allowing the air to more fully contact the outer surface of the smoke pipe 11, thereby improving the heat exchange efficiency between the smoke and the air.

[0037] like Figure 1 , 4 As shown, as one of the preferred embodiments of the utility model, the inner wall of the absorbent tube 21 is provided with an anti-corrosion layer 22 .

[0038] The anti-corrosion layer 22 of the utility model is selected from one of polymer composite materials, ceramic polymer coatings, epoxy resin coatings, and polyurethane coatings. The anti-corrosion layer 22 can effectively prevent the chemical corrosion of the absorption tube 21 caused by sulfur dioxide in the flue gas, thereby avoiding flue gas leakage caused by corrosion of the absorption tube 21.

[0039] Furthermore, structures similar to the anti-corrosion layer 22 are provided on the inner wall of the dust removal mechanism 2, the inner wall of the absorption tower 3, the inner wall of the steam-water separator 8, the inner wall of the tail gas pipe 31, etc., so as to prevent the sulfur dioxide in the flue gas or tail gas from chemically corroding these components.

[0040] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A phosphogypsum decomposition tail gas anti-corrosion treatment device, comprising a decomposition kiln (1), a dust removal mechanism (2), an absorption tower (3), and a tail gas treatment mechanism (4), characterized in that: The top of the decomposition kiln (1) is provided with a flue gas pipe (11) extending to the inlet of the dust removal mechanism (2); the outer shell of the flue gas pipe (11) is provided with a heat exchange pipe (5); one end of the heat exchange pipe (5) close to the decomposition kiln (1) is provided with a hot air pipe (51) extending to one side of the decomposition kiln (1); and the other end is provided with an air inlet (52); the outlet of the dust removal mechanism (2) is provided with an absorption pipe (21) extending to the inlet of the absorption tower (3); and the outlet of the absorption tower (3) is provided with an exhaust pipe (31) extending to the inlet of the exhaust gas treatment mechanism (4); The exhaust gas treatment mechanism (4) comprises the following structure: an adsorption tank (41), the interior of the adsorption tank (41) being hollow to form an adsorption chamber (42), the top of the adsorption chamber (42) being provided with a purification pipe (43) extending outward from the adsorption tank (41), the bottom of the adsorption chamber (42) being provided with a recovery pipe (44) connected to the exhaust gas pipe (31), the adsorption chamber (42) being provided with a feeding worm (45) extending from the top end to the bottom end, and one end of the feeding worm (45) being provided with a driving motor (46).

2. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: The inner shape of the adsorption chamber (42) is cylindrical, and the feeding worm (45) is composed of a shaft located on the axis of the adsorption chamber (42) and a spiral blade spirally wound along the shaft, and the outer edge of the spiral blade extends to the inner wall of the adsorption chamber (42).

3. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: A material storage hopper (6) in communication with the adsorption chamber (42) is provided at the top of the adsorption tank (41), a material feed port (61) is provided at the top of the material storage hopper (6), and a material feed port cover (62) matching the material feed port (61) is hingedly connected to the top of the material storage hopper (6) via a hinge.

4. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: A first dustproof net (32) is provided at one end of the tail gas pipe (31) close to the recovery pipe (44), and a second dustproof net (47) is provided at one end of the purification pipe (43) close to the adsorption chamber (42).

5. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: A recovery hopper (7) is provided at the bottom of the recovery pipe (44), a discharge port (71) is provided at the bottom of the recovery hopper (7), and a discharge port cover (72) matching the discharge port (71) is hingedly connected to the bottom of the recovery hopper (7) via a hinge.

6. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: A steam-water separator (8) is provided on the flue gas pipe (11) between the heat exchange tube (5) and the dust removal mechanism (2).

7. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: A plurality of first spoilers (12) are provided in the flue gas pipe (11), and a plurality of second spoilers (53) are provided in the heat exchange pipe (5).

8. The anti-corrosion treatment equipment for tail gas from phosphogypsum decomposition according to claim 1, characterized in that: The inner wall of the absorbent tube (21) is provided with an anti-corrosion layer (22).

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