Tail gas washing and recycling system for ammonium sulfate fertilizer production

Abstract

A tail gas washing and recycling system for ammonium sulfate fertilizer production comprises a desulfurizing tower (1), a crystallization tank (2), a mother liquor tank (3) and a cyclone (4), a discharge port of the crystallization tank (2) is communicated with a feed port of the cyclone (4) through a crystallization pump (7), and the mother liquor tank (3) is communicated with the inside of a concentration section of the desulfurizing tower (1) through a mother liquor pump (8). The utility model has the advantages that the crystallization tank overflows into the mother liquor tank after being filled with liquor, the mother liquor tank is input into the desulfurization tower through the mother liquor pump to form a closed cycle, the crystallization tank and the desulfurization tower are discontinuously opened through the valve, crystals in the crystallization tank can be quickly formed after the valve is closed, and the centrifugal machine is more smooth in discharging time and large in discharging amount; the fertilizer discharging time is shortened, the fertilizer discharging ammonium sulfate solution density is reduced, pipeline and pump body abrasion is reduced, and the service life of a pipeline and a pump body is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas washing and recovery, in particular to a tail gas washing and recovery system for ammonium sulfate fertilizer production. Background Art

[0002] At present, the tail gas generated during the production process of ammonium sulfate fertilizer is washed and purified by a desulfurization tower. A concentrated ammonium sulfate fertilizer solution will be formed in the washing water. In order to recycle it, the ammonium sulfate fertilizer solution will be crystallized to produce ammonium sulfate fertilizer particles. The existing crystallization tank is directly connected to the desulfurization tower in a cycle. The solution crystals grow slowly, and it is difficult to separate the fertilizer by centrifuge. Utility Model Content

[0003] The purpose of this utility model is to provide a tail gas washing and recovery system for ammonium sulfate fertilizer production in view of the above-mentioned shortcomings.

[0004] The utility model comprises a desulfurization tower, a crystallization tank, a mother liquor tank and a cyclone. The liquid outlet of the concentration section of the desulfurization tower is communicated with the spray pipe of the desulfurization tower and the liquid inlet of the crystallization tank respectively through a concentration pump, and valves are provided on the pipelines of the concentration pump and the crystallization tank. The material outlet of the crystallization tank is communicated with the material inlet of the cyclone through the crystallization pump, the liquid outlet of the cyclone is communicated with the liquid inlet of the crystallization tank through a pipeline, the overflow port of the crystallization tank is communicated with the mother liquor tank through a pipeline, and the mother liquor tank is communicated with the concentration section of the desulfurization tower through the mother liquor pump.

[0005] The crystallization tank includes a tank body, a stirring motor and a stirring shaft. A fixed bracket is provided at the bottom of the tank body. The tank body is a conical structure with a top diameter larger than a bottom diameter. The discharge port of the crystallization tank is located on the side wall at one end of the bottom of the conical structure. The overflow port of the crystallization tank is located on the side wall at one end of the top of the conical structure. The stirring motor is installed on the top of the tank body and drives the stirring shaft to rotate in the tank body. The stirring shaft is symmetrically provided with a pair of stirring blades attached to the side walls of the tank body.

[0006] The top edge of the stirring blade is an inclined structure with a lower end close to the stirring shaft and a higher end close to the side wall of the tank body.

[0007] A group of hollow circular holes with successively smaller diameters are arranged on the stirring blade from top to bottom.

[0008] A cooling water trough is provided on the fixed bracket, and the trough body is located in the cooling water trough.

[0009] The utility model has the advantages that after the crystallization tank is full of liquid, the liquid overflows into the mother liquor tank, and the mother liquor tank is then input into the desulfurization tower through the mother liquor pump to form a closed loop. The crystallization tank and the desulfurization tower are intermittently opened by a valve, and after the valve is closed, it is convenient for crystals in the crystallization tank to form quickly. The centrifuge discharges fertilizer more smoothly and the discharge volume is large, which reduces the fertilizer discharge time, reduces the density of the fertilizer ammonium sulfate solution, reduces the wear of the pipeline and the pump body, and increases the service life of the pipeline and the pump body. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic structural diagram of the utility model.

[0011] Figure 2 It is a schematic diagram of the crystallization tank structure of the utility model. DETAILED DESCRIPTION

[0012] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0013] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0014] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the product of the utility model is usually placed when in use. This is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as limiting the present invention. In addition, if the terms "first", "second", etc. appear in the description of the present invention, they are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0015] In the description of the embodiments of the present invention, it should be noted that, unless otherwise specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0016] As shown in the accompanying drawings, the utility model includes a desulfurization tower 1, a crystallization tank 2, a mother liquor tank 3 and a cyclone 4. The liquid outlet of the concentration section of the desulfurization tower 1 is communicated with the spray pipe of the desulfurization tower 1 and the liquid inlet of the crystallization tank 2 through a concentration pump 5, and a valve 6 is provided on the pipeline between the concentration pump 5 and the crystallization tank 2. The discharge port of the crystallization tank 2 is communicated with the feed port of the cyclone 4 through a crystallization pump 7, the liquid outlet of the cyclone 4 is communicated with the liquid inlet of the crystallization tank 2 through a pipeline, the overflow port of the crystallization tank 2 is communicated with the mother liquor tank 3 through a pipeline, and the mother liquor tank 3 is communicated with the concentration section of the desulfurization tower 1 through a mother liquor pump 8.

[0017] The normal operation of the solution in the concentration section of desulfurization tower 1 is that the concentration pump 5 pumps most of the solution into the spray pipe, spraying and washing the exhaust gas entering the desulfurization tower 1. During the spraying process, it also exchanges heat with the flue gas and then falls back into the concentration section. A small amount of solution is input into the crystallization tank 2 through a pipeline for crystallization. When the crystallization tank 2 is full, it enters the mother liquor tank 3 through the overflow port. The solution in the mother liquor tank 3 is then input into the concentration section of the desulfurization tower 1 through the mother liquor pump 8. In this way, the desulfurization tower 1, crystallization tank 2 and mother liquor tank 3 form a closed loop. At the same time, the crystallization pump 7 circulates the solution in the crystallization tank 2 through the cyclone 4 and then circulates the monomer, separating the crystals and the solution.

[0018] When the production line needs to produce ammonium sulfate fertilizer during the day shift, valve 6 is closed, and the mother liquor pump 8 also stops working. The crystallization pump 7 operates normally, so that the crystals in the crystallization tank 2 grow, the centrifuge discharges smoothly and the discharge volume is large, which reduces the discharge time, reduces the density of the discharged ammonium sulfate solution, reduces the wear of the pipeline and pump body, and increases the service life of the pipeline and pump body.

[0019] Preferably, the crystallization tank 2 includes a tank body 10, a stirring motor 11 and a stirring shaft 12. A fixed bracket is provided at the bottom of the tank body 10. The tank body 10 is a conical structure with a top diameter larger than the bottom diameter. The discharge port of the crystallization tank 2 is located on the side wall at one end of the bottom of the conical structure, and the overflow port of the crystallization tank 2 is located on the side wall at one end of the top of the conical structure. The stirring motor 11 is installed on the top of the tank body 10 and drives the stirring shaft 12 to rotate in the tank body 10. The stirring shaft 12 is symmetrically provided with a pair of stirring blades 13 attached to the side wall of the tank body 10.

[0020] The trough body 10 is a conical structure with a top diameter larger than a bottom diameter, which facilitates the sedimentation and concentration of crystals. The stirring blades 13 are used to shovel off the crystals attached to the inner wall of the trough body 10 and at the same time turn over and loosen the crystals to facilitate rapid discharge from the discharge port.

[0021] The top edge of the stirring blade 13 is an inclined structure with a lower end near the stirring shaft 12 and a higher end near the side wall of the tank body 10. A group of hollow circular holes with gradually smaller diameters are provided on the stirring blade 13 from top to bottom.

[0022] The stirring blade 13 reduces resistance when rotating, and can easily turn over the crystals. At the same time, the hollow circular holes make it easier to disperse the crystals more evenly.

[0023] Furthermore, a cooling water tank 15 is provided on the fixed bracket, and the tank body 10 is located in the cooling water tank 15 .

[0024] The cooling water trough 15 is used to adjust the temperature of the solution in the tank body 10. The optimal crystallization temperature is 40-42°C. In this case, the cooling water trough 15 is sealed and connected to the tank body 10. The height of the cooling water trough 15 is lower than the overflow height of the tank body 10. A circulating water inlet pipe and a circulating water outlet pipe are provided on the cooling water trough 15. When the solution in the tank body 10 needs to be cooled, the circulating water inlet pipe and the circulating water outlet pipe are opened, and external normal temperature water enters to take away the heat of the tank body 10, cool it down, and improve the crystallization efficiency.

Claims

1. A tail gas washing and recovery system for ammonium sulfate fertilizer production, characterized in that The invention comprises a desulfurization tower (1), a crystallization tank (2), a mother liquor tank (3) and a cyclone (4); the liquid outlet of the concentration section of the desulfurization tower (1) is communicated with the spray pipe of the desulfurization tower (1) and the liquid inlet of the crystallization tank (2) respectively through a concentration pump (5); a valve (6) is provided on the pipeline between the concentration pump (5) and the crystallization tank (2); the material outlet of the crystallization tank (2) is communicated with the material inlet of the cyclone (4) through a crystallization pump (7); the liquid outlet of the cyclone (4) is communicated with the liquid inlet of the crystallization tank (2) through a pipeline; the overflow port of the crystallization tank (2) is communicated with the mother liquor tank (3) through a pipeline; and the mother liquor tank (3) is communicated with the concentration section of the desulfurization tower (1) through a mother liquor pump (8).

2. The tail gas washing and recovery system for ammonium sulfate fertilizer production according to claim 1, characterized in that The crystallization tank (2) comprises a tank body (10), a stirring motor (11) and a stirring shaft (12). A fixed bracket is provided at the bottom of the tank body (10). The tank body (10) is a conical structure with a top diameter larger than a bottom diameter. The discharge port of the crystallization tank (2) is located on the side wall at one end of the bottom of the conical structure. The overflow port of the crystallization tank (2) is located on the side wall at one end of the top of the conical structure. The stirring motor (11) is installed at the top of the tank body (10) and drives the stirring shaft (12) to rotate in the tank body (10). The stirring shaft (12) is symmetrically provided with a pair of stirring blades (13) attached to the side wall of the tank body (10).

3. The tail gas washing and recovery system for ammonium sulfate fertilizer production according to claim 2, characterized in that The top edge of the stirring blade (13) is an inclined structure with one end close to the stirring shaft (12) being lower and the other end close to the side wall of the tank body (10) being higher.

4. The tail gas washing and recovery system for ammonium sulfate fertilizer production according to claim 3, characterized in that A group of hollow circular holes with successively smaller diameters are provided on the stirring blade (13) from top to bottom.

5. The tail gas washing and recovery system for ammonium sulfate fertilizer production according to claim 2, characterized in that A cooling water trough (15) is provided on the fixed bracket, and the trough body (10) is located in the cooling water trough (15).

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