Comprehensive recycling device for liquid ammonia absorption liquid of ammonia desulfurization system

Abstract

The utility model discloses a liquid ammonia absorption liquid comprehensive recycling device of an ammonia desulfurization system, and relates to the technical field of boiler tail gas desulfurization. The device comprises a liquid ammonia unloading area, a liquid ammonia storage tank and an absorption tank are arranged on one side of the liquid ammonia unloading area, a gas-phase absorption pipeline and a liquid-phase absorption pipeline are fixedly connected to a port of the liquid ammonia storage tank, and ammonia absorption pipelines are fixedly connected to the side walls of the gas-phase absorption pipeline and the liquid-phase absorption pipeline in a penetrating mode. An absorption liquid storage tank is arranged on one side of the absorption tank, a pit is arranged between the absorption tank and the absorption liquid storage tank, and a mixing doser is arranged on one side of the liquid ammonia unloading area; the device is good in safety, can reduce the content of free acid in an ammonium sulfate product, prevents ammonia absorption liquid from being discharged out of a pit, prevents ammonia gas from overflowing due to the fact that an accident pool is overhauled through self-flow of the pit, affects the safety of operators on a production site, eliminates potential safety hazards on the production site, and improves the product quality.

Description

Technical Field

[0001] This utility model relates to the field of boiler exhaust gas desulfurization technology, specifically a device for the comprehensive recovery and utilization of liquid ammonia absorbent in an ammonia desulfurization system. Background Technology

[0002] Currently, the desulfurization process for flue gas from coal-fired boilers or coal chemical power boilers typically employs ammonia desulfurization technology. Ammonia desulfurization is widely used by various industrial enterprises due to its mature technology, high desulfurization efficiency, wide range of applications, high operational flexibility, and the fact that by-products can be used as fertilizers. Ammonia desulfurization uses liquid ammonia as the desulfurizing agent. In actual production, after the liquid ammonia is unloaded, residual liquid ammonia remains in the unloading pipeline. Based on the need for safe production, this residual liquid ammonia is absorbed. Since ammonia is highly soluble in water, water is commonly used as the ammonia absorbent in industry.

[0003] Due to insufficient oxidation of ammonium sulfate slurry and the introduction of ammonia-containing wastewater from chemical plants during the ammonia desulfurization process, ammonium bisulfite is easily not completely converted into ammonium sulfate, resulting in the enrichment of free acid in the slurry. This leads to a high free acid content in the ammonium sulfate product, posing a risk of exceeding product quality standards.

[0004] Currently, in actual production, the absorbent liquid will form ammonia water with a certain concentration after absorbing liquid ammonia for a long time. Discharging it into the pit will cause a pungent odor to permeate the production site, affecting the on-site working environment and threatening the safety of on-site workers. In order to solve the above problems, the inventor proposed a comprehensive recycling device for liquid ammonia absorbent liquid in an ammonia desulfurization system. Utility Model Content

[0005] To address the safety hazard of pungent odors permeating the production site during the maintenance of the emergency pool in the liquid ammonia system of existing ammonia desulfurization technology by eliminating the discharge pit of the liquid ammonia in the pit, and to improve the quality of ammonium sulfate products through comprehensive recovery of the liquid ammonia absorbent, this utility model aims to provide a comprehensive recovery and utilization device for liquid ammonia absorbent in ammonia desulfurization systems.

[0006] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a comprehensive recovery and utilization device for liquid ammonia absorbent in an ammonia desulfurization system, comprising a liquid ammonia unloading area, a liquid ammonia storage tank and an absorption tank arranged on one side of the liquid ammonia unloading area, a gas phase absorption pipeline and a liquid phase absorption pipeline fixedly connected to the port of the liquid ammonia storage tank, and an ammonia absorption pipeline inserted and fixedly connected to the side walls of the gas phase absorption pipeline and the liquid phase absorption pipeline, the output end of the ammonia absorption pipeline being connected to the input end of the absorption tank, an absorbent liquid storage tank arranged on one side of the absorption tank, a pit arranged between the absorption tank and the absorbent liquid storage tank, a mixing dosing device arranged on one side of the liquid ammonia unloading area, a hydrocyclone arranged at the input end of the mixing dosing device, a centrifuge arranged at the output end of the mixing dosing device, a screw conveyor and a vibrating fluidized bed arranged on one side of the centrifuge, a dust separator and a tail gas scrubbing tank arranged on one side of the vibrating fluidized bed, and a silo arranged on the other side of the vibrating fluidized bed.

[0007] Preferably, the liquid ammonia unloading area is equipped with liquid ammonia storage and transportation tank trucks.

[0008] Preferably, a gas phase ammonia unloading arm is fixedly connected to the end of the gas phase absorption pipeline away from the liquid ammonia storage tank, and an ammonia unloading pump is installed at the end of the liquid phase absorption pipeline away from the liquid ammonia storage tank, with a liquid phase ammonia unloading arm fixedly connected to the input end of the ammonia unloading pump.

[0009] Preferably, the output end of the absorption tank is fixedly connected to an absorbent liquid recovery pipeline, and the end of the absorbent liquid recovery pipeline away from the absorption tank extends into the absorbent liquid storage tank.

[0010] Preferably, an absorbent liquid transfer pump is provided on the side wall of the absorbent liquid recovery pipeline, and a connecting pipe is inserted and fixedly connected to the side wall of the absorbent liquid recovery pipeline and on one side of the absorbent liquid transfer pump. A valve is provided on the side wall of the connecting pipe, and the end of the connecting pipe away from the absorbent liquid recovery pipeline extends into the pit.

[0011] Preferably, the output end of the absorbent storage tank is fixedly connected to a dosing pipeline, a dosing pump is provided on the side wall of the dosing pipeline, and the output end of the dosing pipeline extends into the mixing dosing device.

[0012] Preferably, the output end of the centrifuge corresponds to the input end of the screw conveyor, and the output end of the screw conveyor corresponds to the input end of the vibrating fluidized bed.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0014] 1. This utility model adds an absorbent recovery pipeline and an absorbent transfer pump to the pit of the ammonia desulfurization system. The ammonia absorbent with a certain concentration in the absorption tank is sent to the absorbent storage tank for storage via the absorbent transfer pump. The dosing pump sends the liquid ammonia absorbent in the absorbent storage tank to the ammonium sulfate granulation system to mix and neutralize with the ammonium sulfate slurry, thereby reducing the free acid content in the ammonium sulfate product, avoiding the discharge of ammonia absorbent into the pit, and preventing ammonia gas overflow caused by the pit's gravity-flow maintenance accident pool, which affects the safety of on-site workers. This eliminates safety hazards on the production site and improves product quality.

[0015] 2. This utility model can effectively improve the working environment at the production site while eliminating potential safety hazards, and can also recycle liquid ammonia absorbent to neutralize free acid in ammonium sulfate slurry, thereby improving the quality of ammonium sulfate products and realizing the recycling and utilization of ammonia resources and safe production.

[0016] 3. In this invention, a baffle is provided inside the mixing and dosing device. The baffle can change the flow state of the reaction system and increase the turbidity of the reaction mixture, thereby significantly improving the mixing effect of the reactants. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the processing technology of this utility model.

[0019] Figure 2 This is a schematic diagram of the internal structure of the mixing and dosing device of this utility model.

[0020] In the diagram: 1. Liquid ammonia unloading area; 2. Liquid phase ammonia unloading arm; 3. Gas phase ammonia unloading arm; 4. Ammonia unloading pump; 5. Gas phase absorption pipeline; 6. Liquid phase absorption pipeline; 7. Ammonia absorption pipeline; 8. Liquid ammonia storage tank; 9. Absorption tank; 10. Absorbent liquid recovery pipeline; 11. Sump; 12. Absorbent liquid transfer pump; 13. Absorbent liquid storage tank; 14. Dosing pump; 15. Dosing pipeline; 16. Hydrocyclone; 17. Mixing dosing device; 18. Centrifuge; 19. Screw conveyor; 20. Vibrating fluidized bed; 21. Dust separator; 22. Tail gas scrubbing tank; 23. Hopper; 24. Baffle plate. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0022] Example: Figure 1-2 As shown, this utility model provides a comprehensive recovery and utilization device for liquid ammonia absorbent in an ammonia desulfurization system, including a liquid ammonia unloading area 1. A liquid ammonia storage tank 8 and an absorption tank 9 are arranged on one side of the liquid ammonia unloading area 1. A gas phase absorption pipeline 5 and a liquid phase absorption pipeline 6 are fixedly connected to the port of the liquid ammonia storage tank 8. Ammonia absorption pipelines 7 are fixedly connected to the side walls of both the gas phase absorption pipeline 5 and the liquid phase absorption pipeline 6. The output end of the ammonia absorption pipeline 7 is connected to the input end of the absorption tank 9. An absorption device is arranged on one side of the absorption tank 9. A pit 11 is provided between the liquid storage tank 13, the absorption tank 9 and the absorption liquid storage tank 13. A mixing dosing device 17 is provided on one side of the liquid ammonia unloading area 1. A hydrocyclone 16 is provided at the input end of the mixing dosing device 17. A centrifuge 18 is provided at the output end of the mixing dosing device 17. A screw conveyor 19 and a vibrating fluidized bed 20 are provided on one side of the centrifuge 18. A dust separator 21 and a tail gas scrubbing tank 22 are provided on one side of the vibrating fluidized bed 20. A silo 23 is provided on the other side of the vibrating fluidized bed 20.

[0023] In one possible implementation, the liquid ammonia unloading area 1 is equipped with liquid ammonia storage and transportation tank trucks.

[0024] By adopting the above technical solution, the liquid ammonia unloading area 1 is the designated unloading area for liquid ammonia storage and transportation tank trucks. When unloading ammonia, the liquid ammonia tank trucks need to be loaded with liquid ammonia and parked in the liquid ammonia unloading area 1.

[0025] In one possible implementation, a gas phase absorption pipeline 5 is fixedly connected to a gas phase ammonia unloading arm 3 at the end away from the liquid ammonia storage tank 8, and an ammonia unloading pump 4 is installed at the end of the liquid phase absorption pipeline 6 away from the liquid ammonia storage tank 8. The input end of the ammonia unloading pump 4 is fixedly connected to a liquid phase ammonia unloading arm 2.

[0026] By adopting the above technical solution, the ammonia unloading pump 4 is used to unload ammonia from a liquid ammonia tanker. When unloading ammonia, the liquid phase unloading arm 2 is connected to the liquid phase interface of the liquid ammonia tanker, and the gas phase unloading arm 3 is connected to the gas phase interface of the liquid ammonia tanker. The switch valve on the gas-liquid phase unloading pipeline is opened, and the ammonia unloading pump 4 is started to unload ammonia.

[0027] In one possible embodiment, the output end of the absorption tank 9 is fixedly connected to an absorbent liquid recovery pipeline 10, and the end of the absorbent liquid recovery pipeline 10 away from the absorption tank 9 extends into the absorbent liquid storage tank 13. In another possible embodiment, an absorbent liquid transfer pump 12 is provided on the side wall of the absorbent liquid recovery pipeline 10, and a connecting pipe is inserted and fixedly connected to the side wall of the absorbent liquid recovery pipeline 10 and on one side of the absorbent liquid transfer pump 12. A valve is provided on the side wall of the connecting pipe, and the end of the connecting pipe away from the absorbent liquid recovery pipeline 10 extends into the pit 11.

[0028] By adopting the above technical solution, during ammonia unloading, the liquid phase ammonia unloading arm 2 is connected to the liquid phase interface of the liquid ammonia tanker, and the gas phase ammonia unloading arm 3 is connected to the gas phase interface of the liquid ammonia tanker. The switch valves on the gas-liquid phase ammonia unloading pipelines are opened, and the ammonia unloading pump 4 is started to unload ammonia. The operator determines whether the ammonia unloading is complete based on the liquid level gauges on the liquid ammonia tanker and the local liquid ammonia storage tank 8. After the ammonia unloading is completed, the switch valves on the gas-liquid phase ammonia unloading pipelines are closed, and the connections of the liquid phase ammonia unloading arm 2 and the gas phase ammonia unloading arm 3 to the liquid ammonia tanker are disconnected. The switch valve on the ammonia absorption pipeline 7 is slowly opened to absorb the residual ammonia in the gas phase absorption pipeline 5 and the liquid phase absorption pipeline 6 in the absorption tank 9. The absorbent is periodically recovered through the absorbent. Pipeline 10 delivers absorbent to absorbent storage tank 13 via absorbent transfer pump 12. Note that absorbent recovery involves opening the bottom valves of absorbent tank 9 and the inlet valve of absorbent storage tank 13, opening the inlet valve of absorbent transfer pump 12, and closing the valve on the discharge pit 11 pipeline. The absorbent transfer pump 12 is then activated to transfer the absorbent from absorbent tank 9 to absorbent storage tank 13. After the absorbent transfer is complete, the relevant pipeline valves are closed, and the water supply to absorbent tank 9 is activated to replenish the absorbent in absorbent tank 9. It is also important to note that in the event of an accident or emergency, the absorbent must be discharged into pit 11 by opening the valve on the connecting pipe. Pit 11 will then allow gravity flow to the maintenance accident pool, ensuring safe system operation.

[0029] In one possible implementation, the output end of the absorbent storage tank 13 is fixedly connected to a dosing pipeline 15, and a dosing pump 14 is provided on the side wall of the dosing pipeline 15. The output end of the dosing pipeline 15 extends into the mixing and dosing device 17. In another possible implementation, the output end of the centrifuge 18 corresponds to the input end of the screw conveyor 19, and the output end of the screw conveyor 19 corresponds to the input end of the vibrating fluidized bed 20.

[0030] By adopting the above technical solution, a motor is installed on the top surface of the mixing dosing device 17, and a stirring paddle is fixedly connected to the output shaft end of the motor. The stirring paddle is located inside the mixing dosing device 17. The mixing dosing device 17 can mix the solution, and a baffle 24 is installed inside the mixing dosing device 17. The baffle 24 can change the flow state of the reaction system and increase the degree of chaos of the reaction mixture, thereby significantly improving the mixing effect of the reactants. An ammonium sulfate granulation system is installed on one side of the hydrocyclone 16. The ammonium sulfate granulation system includes an ammonium sulfate granulator, which mainly consists of a base support, granulation rollers, a crushing chamber, and a motor drive. Its working principle is that after the material enters the hopper, it is pressed into spherical particles by a high-pressure roller, and then flows down along the crushing chamber and is separated into individual particles through the required sieve. When the ammonium sulfate granulation system is running, under the action of the dosing pump 14, ammonia in the absorbent storage tank 13 is absorbed through the dosing pipeline 15. The collected liquid is sent to the mixing dosing device 17 to neutralize the ammonium sulfate slurry, reducing the free acid content of the ammonium sulfate product. The ammonia desulfurization technology and the mixing dosing device 17 are existing mature technologies and products, and will not be elaborated on further here. It should be noted that when the ammonium sulfate granulation system is running, after the slurry in the desulfurization tower concentration section is initially separated by the hydrocyclone 16, the thin slurry returns to the desulfurization tower concentration section, and the concentrated slurry is neutralized by the ammonia absorption liquid from the dosing pipeline 15 through the mixing dosing device 17 and then flows by gravity into the centrifuge 18 for dehydration. After dehydration, the ammonium sulfate product is conveyed by the screw conveyor 19 into the vibrating fluidized bed 20 for drying. The ammonium sulfate dust generated during the drying process is separated by the dust separator 21 and falls into the silo 23. The tail gas separated by the dust separator 21 is purified by the tail gas scrubbing tank 22 and then discharged into the air. The scrubbing liquid is returned to the absorption section of the desulfurization tower. The ammonium sulfate product in the screw conveyor 19 enters the vibrating fluidized bed 20 for drying and then enters the silo 23 for bagging and sale.

[0031] Working principle: When using this utility model, the liquid ammonia tanker is loaded with liquid ammonia and parked in the liquid ammonia unloading area 1. The liquid phase unloading arm 2 is connected to the liquid phase interface of the liquid ammonia tanker, and the gas phase unloading arm 3 is connected to the gas phase interface of the liquid ammonia tanker. The switch valve on the gas-liquid phase unloading pipeline is opened, and the unloading pump 4 is started to unload ammonia. In actual on-site operation, the operator needs to determine whether to stop unloading ammonia based on the liquid level gauge of the liquid ammonia tanker and the local liquid level gauge of the liquid ammonia storage tank 8.

[0032] After the ammonia is unloaded, close the switch valve on the gas-liquid phase ammonia unloading pipeline, disconnect the connection between the liquid phase ammonia unloading arm 2 and the gas phase ammonia unloading arm 3 and the liquid ammonia tanker, and slowly open the switch valve on the ammonia absorption pipeline 7 to absorb the ammonia remaining in the gas phase absorption pipeline 5 and the liquid phase absorption pipeline 6 in the absorption tank 9. The absorption liquid is periodically sent to the absorption liquid storage tank 13 by the absorption liquid transfer pump 12 through the absorption liquid recovery pipeline 10.

[0033] When the ammonium sulfate granulation system is running, the ammonia absorbent in the absorbent storage tank 13 is sent to the mixing dosing device 17 via the dosing pump 14 and dosing pipeline 15 to neutralize the ammonium sulfate slurry, reducing the free acid content of the ammonium sulfate product. It should be noted that the absorption liquid recovery is achieved by opening the bottom valve of the absorption tank 9 and the inlet valve of the absorbent storage tank 13, opening the inlet valve of the absorbent transfer pump 12, closing the valve on the discharge pit pipeline 11, and starting the absorbent transfer pump 12 to transfer the absorbent from the absorption tank 9 to the absorbent storage tank. After the absorbent liquid is transferred in tank 13, the relevant pipeline valves are closed, and the water supply to absorbent tank 9 is turned on to replenish the absorbent liquid in absorbent tank 9. At the same time, when the ammonium sulfate granulation system is running, the dosing pump 14 is turned on to send the ammonia recovery liquid to the mixing dosing device 17 to neutralize the ammonium sulfate slurry, thereby reducing the free acid content in the ammonium sulfate slurry. In case of accident or emergency, the absorbent liquid can be discharged into pit 11 by opening the valve on the connecting pipe, and the pit 11 will flow by gravity into the maintenance accident pool to ensure the safe operation of the system.

[0034] Furthermore, during the operation of the ammonium sulfate granulation system, after the slurry in the concentration section of the desulfurization tower is initially separated by the hydrocyclone 16, the thin slurry returns to the concentration section of the desulfurization tower, and the concentrated slurry is neutralized and reacted with the ammonia absorption liquid from the dosing pipeline 15 by the mixing and dosing device 17 before flowing into the centrifuge 18 for dehydration. After dehydration, the ammonium sulfate product is conveyed by the screw conveyor 19 into the vibrating fluidized bed 20 for drying. The ammonium sulfate dust generated during the drying process is separated by the dust separator 21 and falls into the silo 23. The tail gas separated by the dust separator 21 is purified by the tail gas scrubbing tank 22 and then discharged into the air. The scrubbing liquid returns to the absorption section of the desulfurization tower. The ammonium sulfate product in the screw conveyor 19 enters the vibrating fluidized bed 20 for drying and then enters the silo 23 for bagging and sale.

[0035] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A comprehensive recovery and utilization device for liquid ammonia absorbent in an ammonia desulfurization system, comprising a liquid ammonia unloading area (1), characterized in that: A liquid ammonia storage tank (8) and an absorption tank (9) are provided on one side of the liquid ammonia unloading area (1). A gas phase absorption pipeline (5) and a liquid phase absorption pipeline (6) are fixedly connected to the port of the liquid ammonia storage tank (8). An ammonia absorption pipeline (7) is inserted and fixedly connected to the side walls of both the gas phase absorption pipeline (5) and the liquid phase absorption pipeline (6). The output end of the ammonia absorption pipeline (7) is connected to the input end of the absorption tank (9). An absorbent liquid storage tank (13) is provided on one side of the absorption tank (9). A connection is provided between the absorption tank (9) and the absorbent liquid storage tank (13). A pit (11) is provided. A mixing dosing device (17) is provided on one side of the liquid ammonia unloading area (1). A hydrocyclone (16) is provided at the input end of the mixing dosing device (17). A centrifuge (18) is provided at the output end of the mixing dosing device (17). A screw conveyor (19) and a vibrating fluidized bed (20) are provided on one side of the centrifuge (18). A dust separator (21) and a tail gas scrubbing tank (22) are provided on one side of the vibrating fluidized bed (20). A silo (23) is provided on the other side of the vibrating fluidized bed (20).

2. The ammonia absorption liquid comprehensive recovery and utilization device for an ammonia desulfurization system as described in claim 1, characterized in that, The liquid ammonia unloading area (1) is equipped with liquid ammonia storage and transportation tankers.

3. The ammonia absorption liquid comprehensive recovery and utilization device for an ammonia desulfurization system as described in claim 1, characterized in that, The gas phase absorption pipeline (5) is fixedly connected to a gas phase ammonia unloading arm (3) at the end away from the liquid ammonia storage tank (8), and an ammonia unloading pump (4) is provided at the end of the liquid phase absorption pipeline (6) away from the liquid ammonia storage tank (8). The input end of the ammonia unloading pump (4) is fixedly connected to a liquid phase ammonia unloading arm (2).

4. The ammonia absorption liquid comprehensive recovery and utilization device for an ammonia desulfurization system as described in claim 1, characterized in that, The output end of the absorption tank (9) is fixedly connected to the absorption liquid recovery pipeline (10), and the end of the absorption liquid recovery pipeline (10) away from the absorption tank (9) extends into the absorption liquid storage tank (13).

5. The ammonia absorption liquid comprehensive recovery and utilization device for an ammonia desulfurization system as described in claim 4, characterized in that, An absorbent liquid transfer pump (12) is provided on the side wall of the absorbent liquid recovery pipeline (10). A connecting pipe is inserted and fixedly connected to the side wall of the absorbent liquid recovery pipeline (10) and on one side of the absorbent liquid transfer pump (12). A valve is provided on the side wall of the connecting pipe, and the end of the connecting pipe away from the absorbent liquid recovery pipeline (10) extends into the pit (11).

6. The ammonia absorption liquid comprehensive recovery and utilization device for an ammonia desulfurization system as described in claim 1, characterized in that, The output end of the absorbent storage tank (13) is fixedly connected to a dosing pipeline (15), and a dosing pump (14) is provided on the side wall of the dosing pipeline (15). The output end of the dosing pipeline (15) extends into the mixing dosing device (17).

7. The ammonia absorption liquid comprehensive recovery and utilization device for an ammonia desulfurization system as described in claim 1, characterized in that, The output end of the centrifuge (18) corresponds to the input end of the screw conveyor (19), and the output end of the screw conveyor (19) corresponds to the input end of the vibrating fluidized bed (20).

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