Ammonia gas recovery system of nitric acid device

Abstract

The utility model discloses a gas ammonia recovery system of a nitric acid device, which comprises a desalted water pipeline, a gas ammonia discharge pipeline, a gas ammonia emptying pipeline, a low-pressure steam pipeline and a gas ammonia recovery tank, the gas ammonia recovery tank is provided with a water replenishing port, a gas ammonia inlet, a tail gas outlet, a safety valve interface and an ammonia water discharge port, and the desalted water pipeline is connected with the water replenishing port. The ammonia gas discharging pipeline is connected with the ammonia gas inlet, the tail gas outlet is connected with the ammonia gas emptying pipeline, an ammonia gas discharging bypass is arranged on the ammonia gas discharging pipeline in a branched mode, the tail end of the ammonia gas discharging bypass is connected to the ammonia gas emptying pipeline, the low-pressure steam pipeline is connected with the ammonia gas emptying pipeline, and the ammonia water discharging port is connected with the ammonia water conveying pipeline. According to the utility model, the process flow is improved, so that the environmental pollution caused by the discharged ammonia gas is effectively avoided, the ammonia gas is dissolved and absorbed into ammonia water through desalted water according to the dissolving characteristic of the discharged ammonia gas, and then the ammonia water is conveyed to an ammonia water preparation procedure through an ammonia water conveying pump, so that the loss and waste of the raw ammonia gas are avoided, and the pollution to the atmospheric environment is also avoided.

Description

Technical Field

[0001] This utility model relates to the field of industrial ammonia recovery, specifically to an ammonia recovery system for a nitric acid plant. Background Technology

[0002] In the dual-pressure process for producing dilute nitric acid, oxygen in the air reacts with ammonia under the action of a catalyst to produce nitrogen oxides, which are then absorbed by water in an absorption tower to generate dilute nitric acid with a content greater than 63.5 wt%. During start-up and shutdown, ammonia-air ratio adjustments, and in the event of sudden process fluctuations or equipment failures, some of the raw material ammonia is directly emitted into the atmosphere. If effective measures are not taken to recover and utilize this ammonia, not only will a large amount of ammonia escape, but it will also pollute the atmosphere and result in a waste of raw materials.

[0003] If a gaseous ammonia recovery system for a nitric acid plant is designed to recover and utilize this gaseous ammonia, it can not only increase economic benefits and reduce production costs, but also effectively protect and improve the regional ecological environment, thereby achieving the goal of reducing or even achieving "zero emissions" of pollution emissions from nitric acid production. Utility Model Content

[0004] The main objective of this invention is to provide a gaseous ammonia recovery system for a nitric acid plant. The system includes a newly added gaseous ammonia recovery tank with an inlet located on the side of the tank, near the bottom. A pipeline runs parallel into the tank and connects to a gas distributor. The outlet is located at the top center of the tank. Gaseous ammonia dissolves in demineralized water to produce ammonia water, which is then pumped to an ammonia water unit for recycling. This technical solution effectively recovers gaseous ammonia generated during start-up and shutdown, ammonia-air ratio preparation, and in case of sudden process fluctuations or equipment failures. This avoids the emission of gaseous ammonia into the air, protecting the environment and air quality. Furthermore, the recovered ammonia water can be used in other processes.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0006] A gaseous ammonia recovery system for a nitric acid plant includes a demineralized water pipeline, a gaseous ammonia discharge pipeline, a gaseous ammonia venting pipeline, a low-pressure steam pipeline, and a gaseous ammonia recovery tank. The gaseous ammonia recovery tank is equipped with a water inlet, a gaseous ammonia inlet, a tail gas outlet, a safety valve interface, and an ammonia water drain outlet. The demineralized water pipeline is connected to the water inlet, the gaseous ammonia discharge pipeline is connected to the gaseous ammonia inlet, the tail gas outlet is connected to the gaseous ammonia venting pipeline, a gaseous ammonia discharge bypass is branched off from the gaseous ammonia discharge pipeline, the end of the gaseous ammonia discharge bypass is connected to the gaseous ammonia venting pipeline, the low-pressure steam pipeline is connected to the gaseous ammonia venting pipeline, and the ammonia water drain outlet is connected to the ammonia water delivery pipeline.

[0007] Furthermore, a wire mesh demister is installed at the top of the ammonia recovery tank, and a gas distributor is installed at the bottom. The inlet of the gas distributor is the ammonia inlet. Support legs are provided at the bottom of the ammonia recovery tank. The tail gas outlet and safety valve interface are located at the top of the ammonia recovery tank. The water inlet and ammonia inlet are located on the side wall of the ammonia recovery tank. The ammonia inlet is located near the bottom of the ammonia recovery tank, the water inlet is located higher than the ammonia inlet, and the ammonia water drain outlet is located at the bottom of the ammonia recovery tank.

[0008] Furthermore, the top of the ammonia recovery tank is equipped with a pressure gauge interface, and the side wall of the ammonia recovery tank is also equipped with a manhole, a reserved ammonia water inlet, a first on-site level gauge port, and a second on-site level gauge port. The water supply port is set opposite to the reserved ammonia water inlet, and the position of the first on-site level gauge port is higher than the position of the second on-site level gauge port. The flange sealing surfaces of the first on-site level gauge port and the second on-site level gauge port should be in the same position and on the same plumb line.

[0009] Furthermore, the air distributor includes a main pipe, on which a plurality of connecting holes are evenly arranged, the connecting holes being arranged in one row, multiple rows, or staggered, and branch pipes are provided on the connecting holes, each branch pipe being provided with a plurality of air holes, the air holes being arranged in one row, multiple rows, or staggered.

[0010] Furthermore, a pressure self-regulating valve for the ammonia recovery tank is installed on the low-pressure steam pipeline.

[0011] Furthermore, an ammonia delivery pump is installed on the ammonia delivery pipeline.

[0012] Furthermore, the outriggers are equipped with electrostatic grounding plates.

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

[0014] This utility model relates to a gaseous ammonia recovery system for a nitric acid plant. It includes a newly added gaseous ammonia recovery tank body and support legs, an ammonia water delivery pump, a demineralized water pipeline, and a low-pressure steam pipeline. The new system uses a newly added gaseous ammonia recovery tank with an inlet located on the side of the tank body near the bottom. A pipeline parallel to the tank acts as a gas distributor, and the outlet is located at the center of the tank top. Gaseous ammonia dissolves in the demineralized water to produce ammonia water, which is then pumped to an ammonia water unit for recycling. This effectively recovers this portion of gaseous ammonia, increasing economic benefits, achieving resource recovery, reducing energy and material consumption, and preventing the release of gaseous ammonia that pollutes the atmosphere. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of this utility model;

[0016] Figure 2 yes Figure 1 Schematic diagram of the intermediate gas ammonia recovery tank;

[0017] Figure 3 This is a schematic diagram of the air distributor;

[0018] In the diagram: 1. Exhaust gas outlet; 2. Safety valve interface; 3. Manhole; 4. First on-site level gauge interface; 5. Reserved ammonia inlet; 6. Distributor; 6-1. Main pipeline; 6-2. Branch pipeline; 6-3. Vent; 7. Second on-site level gauge interface; 8. Ammonia drain outlet; 9. Pressure gauge interface; 10. Wire mesh demister; 11. Water inlet; 12. Ammonia inlet; 13. Support leg; 14. Static grounding plate; 15. Ammonia discharge bypass; 16. Demineralized water pipeline; 17. Ammonia discharge pipeline; 18. Ammonia vent pipeline; 19. Low-pressure steam pipeline; 20. Ammonia delivery pipeline; 21. Ammonia delivery pump. Detailed Implementation

[0019] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0020] A gaseous ammonia recovery system for a nitric acid plant, such as Figure 1 As shown, it includes a demineralized water pipeline 16, a gaseous ammonia discharge pipeline 17, a gaseous ammonia venting pipeline 18, a low-pressure steam pipeline 19, and a gaseous ammonia recovery tank, such as... Figure 2 As shown, the ammonia recovery tank has a water inlet 11 and an ammonia inlet 12 on its side wall, a tail gas outlet 1, a safety valve interface 2 and a pressure gauge interface 9 on its top, and an ammonia water drain outlet 8 at its bottom. The water inlet 11 is positioned higher than the ammonia inlet 12. The demineralized water pipeline 16 is connected to the water inlet 11, the ammonia discharge pipeline 17 is connected to the ammonia inlet 12, the tail gas outlet 1 is connected to the ammonia vent pipeline 18, the ammonia discharge pipeline 17 has a branch ammonia discharge bypass 15, the end of the ammonia discharge bypass 15 is connected to the ammonia vent pipeline 18, the low-pressure steam pipeline 19 is connected to the ammonia vent pipeline 18, and the ammonia water drain outlet 8 is connected to the ammonia water delivery pipeline 20 to deliver the ammonia water to the ammonia water process.

[0021] The upper part of the ammonia recovery tank is equipped with a wire mesh demister 10, and the lower part is equipped with a gas distributor 6. The inlet of the gas distributor 6 is the ammonia inlet 12. The bottom of the ammonia recovery tank is equipped with support legs 13, and the support legs 13 are equipped with electrostatic grounding plates 14. The ammonia inlet 12 is located near the bottom of the ammonia recovery tank, and the water inlet 11 is located higher than the ammonia inlet 12. The side wall of the ammonia recovery tank is also equipped with a manhole 3, a first on-site level gauge port 4, a second on-site level gauge port 7, and a reserved ammonia water inlet 5. The water inlet 11 is located opposite to the reserved ammonia water inlet 5, and the first on-site level gauge port 4 is located higher than the second on-site level gauge port 7. The flange sealing surfaces of the first on-site level gauge port 4 and the second on-site level gauge port 7 should be in the same position and on the same plumb line.

[0022] The gas distributor 6 includes a main pipe 6-1, on which a plurality of connecting holes are evenly arranged. These connecting holes are arranged in one row, multiple rows, or staggered arrangements. Branch pipes 6-2 are provided on each connecting hole, and each branch pipe 6-2 has a plurality of air holes 6-3, which are also arranged in one row, multiple rows, or staggered arrangements. An ammonia discharge pipeline 17 is connected to the main pipe 6-1.

[0023] A pressure regulating valve for the ammonia recovery tank is installed on the low-pressure steam pipeline 19. An ammonia water delivery pump 21 is installed on the ammonia water delivery pipeline 20.

[0024] The working process of this utility model is as follows: by adding a gaseous ammonia recovery tank, the vented gaseous ammonia enters the gaseous ammonia recovery tank through the gaseous ammonia discharge pipeline 17. The inlet is located on the side of the tank body, away from the bottom of the tank. The pipeline enters the tank parallel to the bottom and is connected to the gas distributor 6. The gaseous ammonia is evenly distributed through the gas distributor 6, so that the gaseous ammonia can fully contact the demineralized water. The end outlet is located in the middle of the top of the tank. The insoluble gas is separated by the wire mesh demister 10 and then released into the air. The dissolved gaseous ammonia becomes ammonia water, which is then sent to the ammonia water device for recycling through the ammonia water transfer pump 21.

[0025] In practical applications, adding a low-pressure steam pipeline 19 to the ammonia venting pipeline 18 serves the following purposes: First, it prevents the ammonia from liquefying in the pipeline. Ammonia is easily affected by temperature; if the temperature drops, it may liquefy. Introducing low-pressure steam can appropriately raise the temperature, keeping the ammonia in a gaseous state and ensuring its smooth transport in the pipeline. Second, when the pipeline needs cleaning or maintenance, the low-pressure steam can be used to purge the ammonia pipeline, removing residual ammonia and other impurities.

[0026] This invention is ingeniously conceived and practically reliable. Through a gaseous ammonia recovery system for a nitric acid plant, it can fully recover and utilize this gaseous ammonia, not only increasing economic benefits and achieving resource recovery, but also reducing energy costs and avoiding the release of gaseous ammonia that pollutes the atmosphere. It aligns with current requirements for energy conservation, emission reduction, and green environmentally friendly production, making it a win-win situation.

[0027] The preferred embodiments and examples of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the concept of the present invention.

Claims

1. A gaseous ammonia recovery system for a nitric acid plant, characterized in that, It includes a demineralized water pipeline, a gaseous ammonia discharge pipeline, a gaseous ammonia venting pipeline, a low-pressure steam pipeline, and a gaseous ammonia recovery tank. The gaseous ammonia recovery tank is equipped with a water inlet, a gaseous ammonia inlet, a tail gas outlet, a safety valve interface, and an ammonia water drain outlet. The demineralized water pipeline is connected to the water inlet, the gaseous ammonia discharge pipeline is connected to the gaseous ammonia inlet, the tail gas outlet is connected to the gaseous ammonia venting pipeline, a branch of the gaseous ammonia discharge pipeline is provided, the end of the gaseous ammonia discharge bypass is connected to the gaseous ammonia venting pipeline, the low-pressure steam pipeline is connected to the gaseous ammonia venting pipeline, and the ammonia water drain outlet is connected to the ammonia water delivery pipeline.

2. The ammonia recovery system for the nitric acid apparatus according to claim 1, characterized in that, The upper part of the ammonia recovery tank is equipped with a wire mesh demister, and the lower part is equipped with a gas distributor. The inlet of the gas distributor is the ammonia inlet. The bottom of the ammonia recovery tank is equipped with support legs. The tail gas outlet and safety valve interface are located at the top of the ammonia recovery tank. The water inlet and ammonia inlet are located on the side wall of the ammonia recovery tank. The ammonia inlet is located near the bottom of the ammonia recovery tank, and the water inlet is located higher than the ammonia inlet. The ammonia water drain outlet is located at the bottom of the ammonia recovery tank.

3. The ammonia recovery system for the nitric acid apparatus according to claim 1 or 2, characterized in that, The top of the ammonia recovery tank is also equipped with a pressure gauge interface. The side wall of the ammonia recovery tank is also equipped with a manhole, a reserved ammonia water inlet, a first on-site level gauge port and a second on-site level gauge port. The water supply port is set opposite to the reserved ammonia water inlet, and the position of the first on-site level gauge port is higher than the position of the second on-site level gauge port. The flange sealing surfaces of the first on-site level gauge port and the second on-site level gauge port should be in the same position and on the same plumb line.

4. The ammonia recovery system for the nitric acid apparatus according to claim 2, characterized in that, The air distributor includes a main pipe with a number of connecting holes evenly arranged on it. The connecting holes are arranged in one row, multiple rows, or staggered. Branch pipes are provided on the connecting holes, and each branch pipe is provided with a number of air holes, which are arranged in one row, multiple rows, or staggered.

5. The ammonia recovery system for the nitric acid apparatus according to claim 1, characterized in that, The low-pressure steam pipeline is equipped with a pressure self-regulating valve for the ammonia recovery tank.

6. The ammonia recovery system for the nitric acid apparatus according to claim 1, characterized in that, An ammonia water delivery pump is installed on the ammonia water delivery pipeline.

7. The ammonia recovery system for the nitric acid apparatus according to claim 2, characterized in that, The outriggers are equipped with electrostatic grounding plates.

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