Ammonia collecting, washing and purifying device for liquid ammonia storage tank

Abstract

The utility model discloses an ammonia collecting, washing and purifying device for a liquid ammonia storage tank, belongs to the technical field of coke oven gas chemical product recovery and anhydrous ammonia production, and solves the problems that the absorption efficiency is low and the ammonia gas is not thoroughly collected when ammonia gas escaped from the liquid ammonia storage tank and a liquid ammonia loading area is subjected to spraying type washing. The device comprises an ammonia gas washing buffer tank, an ammonia water absorption tank and a separation water tank, the ammonia gas washing buffer tank is respectively provided with a dissipated ammonia gas collecting pipeline and an industrial water replenishing pipeline, the ammonia gas washing buffer tank is connected with the ammonia water absorption tank through an ammonia gas bubbling pipe, the ammonia water absorption tank is provided with a dissipated ammonia gas collecting and discharging pipe, and the industrial water replenishing pipeline is connected with the industrial water replenishing pipeline. The ammonia water absorption tank is connected with the separation water tank through an ammonia water absorption tank wastewater discharge pipe; and a separation water tank self-priming pump is arranged on the separation water tank. According to the utility model, the problems of environmental pollution and influence on physical and psychological health of workers caused by ammonia gas dissipation in the liquid ammonia storage tank area are solved and eliminated, and long-term stable operation and on-site environmental governance of the liquid ammonia storage tank and the liquid ammonia loading area are facilitated.

Description

Technical Field

[0001] This utility model belongs to the field of coke oven gasification product recovery and anhydrous ammonia production technology, specifically relating to an ammonia collection, washing and purification device for liquid ammonia storage tank. Background Technology

[0002] After being cooled by an indirect primary cooler, the raw coal gas from the coke oven contains 4-8 g / m³ of ammonia. 3 When washing benzene with wash oil, ammonia in the coal gas can also be absorbed by the wash oil, which can easily lead to emulsification and deterioration of the wash oil, increasing the consumption of wash oil; high ammonia content in rich oil can cause corrosion of equipment and pipelines in the benzene removal system; ammonia in coal gas will produce nitrogen oxides when burned, causing environmental pollution, so ammonia in coal gas must be removed.

[0003] Methods for removing ammonia from coal gas generally include the process of producing concentrated ammonia water by washing ammonia with water and then steaming ammonia, the process of producing ammonium sulfate by spray saturator, and the process of producing anhydrous ammonia by absorbing ammonia with phosphoric acid.

[0004] The Fursam process uses ammonium phosphate aqueous solution as the absorbent to recover ammonia from coke oven gas. Ammonium phosphate aqueous solution, as an ammonia absorbent, has advantages such as stability, non-deterioration, non-volatility, and no need for periodic replacement or purification. The process flow for producing anhydrous ammonia by absorbing ammonia with ammonium phosphate is as follows: Coke oven gas from the desulfurization tower enters the lower section of the ammonia absorption tower, where it comes into countercurrent contact with the ammonium phosphate solution. More than 95% of the ammonia in the gas is absorbed in the lower section. After entering the middle and upper sections of the ammonia absorption tower, the remaining ammonia is further absorbed. The ammonia-removed gas is discharged from the top of the ammonia absorption tower to the gas final cooler.

[0005] The ammonium phosphate (rich solution) solution, after absorbing ammonia, is pumped to the desorption distillation unit via a lower-stage solution circulation pump. After tar removal by a tar remover, it enters a lean-rich solution heat exchanger for heat exchange, then passes through a separator to remove acid gas before entering the desorption tower for distillation to desorb some of the ammonia from the rich solution. The lean solution after distillation is returned to the ammonia absorption tower; the produced concentrated ammonia water enters the distillation tower for further distillation and purification, ultimately producing liquid ammonia with a purity ≥99.6%.

[0006] Before desorption, the rich liquor needs to undergo tar removal, heat exchange with the lean liquor, and deacidification treatment. Then, it is sent to the top of the desorption tower via a rich liquor pressurization pump. The desorption tower is operated at a pressure of ~1.3MPa, and direct steam at ~1.6MPa is introduced into the bottom of the tower. The lean liquor at the bottom of the tower is returned to the top of the absorption tower for recycling after passing through a lean-rich liquor heat exchanger and a lean liquor cooler. Ammonia vapor escaping from the top of the desorption tower is condensed and cooled to its boiling point temperature to form ammonia water, which is then directly fed into the distillation feed tank. To further remove acidic gases from the ammonia water, a 30% NaOH solution is continuously fed into the distillation feed tank using a liquid alkali metering pump. Concentrated ammonia water is sent to the middle of the distillation tower by the distillation tower feed pump. Ammonia vapor with a purity of not less than 99.8% is distilled off from the top of the distillation tower and cooled to ~39.9℃ by the distillation tower condenser. The liquid ammonia then enters the reflux tank, where it is pressurized by the distillation tower reflux pump. Part of the liquid ammonia is used as top reflux, and the other part is sent as product to the liquid ammonia storage tank in the oil depot unit. The product is used for denitrification of flue gas in power plants and coke ovens.

[0007] Liquid ammonia in the oil depot unit is temporarily stored in storage tanks and transported to various users by tank trucks. After loading of liquid ammonia into the tank trucks, the residual liquid ammonia in the vapor phase pipe is placed into the ammonia scrubber. At this time, the spray device automatically starts to dilute the ammonia gas into ammonia water, which flows into the ammonia water tank by gravity. When there is a liquid level in the ammonia water tank, it is discharged into the benzene separation water underground tank through the vent pipe. Based on the liquid level in the benzene separation water underground tank, after contacting the blower operation control station, the external pump of the benzene separation water underground tank is started to send the ammonia water to the tar ammonia water separation tank.

[0008] The collection, washing, and purification device for residual liquid ammonia in the vapor phase pipe after loading into the oil depot area is a key environmental protection equipment. Existing scrubbers have problems such as low absorption efficiency, incomplete ammonia collection and absorption, and ammonia leakage that pollutes the environment. Utility Model Content

[0009] The purpose of this invention is to provide an ammonia collection, washing, and purification device for liquid ammonia storage tanks, in order to solve the problems of low absorption efficiency and incomplete ammonia collection caused by spray washing of ammonia gas escaping from liquid ammonia storage tanks and liquid ammonia loading areas.

[0010] The technical solution of this utility model is: a liquid ammonia storage tank ammonia collection, washing and purification device. The main body of the liquid ammonia storage tank ammonia collection, washing and purification device includes an ammonia gas washing buffer tank, an ammonia water absorption tank and a separation water tank. The ammonia gas washing buffer tank is respectively equipped with an escaping ammonia gas collection pipeline and an industrial water replenishment pipeline. The ammonia gas washing buffer tank is connected to the ammonia water absorption tank through an ammonia gas bubbling pipe. There are two ammonia gas bubbling pipes, one of which is connected from the top of the ammonia gas washing buffer tank and the other is connected from the middle of the side of the ammonia gas washing buffer tank. The two ammonia gas bubbling pipes extend below the liquid surface of the ammonia water absorption tank. An ammonia gas washing buffer tank venting pipeline is also provided between the ammonia gas washing buffer tank and the ammonia water absorption tank. An escaping ammonia gas collection and discharge pipe is provided on the ammonia water absorption tank. The ammonia water absorption tank is connected to the separation water tank through an ammonia water absorption tank wastewater discharge pipe. A separation water tank self-priming pump is provided on the separation water tank. The separation water tank self-priming pump is connected to the lower interface of the separation water tank and is interlocked with the liquid level of the separation water tank.

[0011] As a further improvement of this utility model, the ammonia gas collection pipeline is connected to the liquid ammonia loading vapor phase pipeline, and a control valve is provided before entering the ammonia gas washing buffer tank; the industrial water replenishment pipeline is connected to the fresh water pipeline, and a control valve is provided before entering the ammonia gas washing buffer tank; the ammonia gas washing buffer tank vent pipeline is located at the bottom of the ammonia gas washing buffer tank and is equipped with a control valve; the ammonia gas collection and discharge pipe is connected to the negative pressure removal system pipeline, and a control valve is provided at the top of the ammonia water absorption tank.

[0012] As a further improvement of this utility model, the ammonia washing buffer tank is a horizontal storage tank with a breather valve at the top; the ammonia water absorption tank is a vertical storage tank with a level gauge and a breather valve on its main body; and the separation water tank is a horizontal storage tank with a level gauge and a breather valve on its main body.

[0013] As a further improvement of this utility model, the wastewater discharge pipe of the ammonia absorption tank is connected to the upper interface of the separation tank and is equipped with a control valve. The wastewater discharge pipe of the ammonia absorption tank is also equipped with a full flow pipe.

[0014] The beneficial effects of this utility model are as follows: This utility model solves the problems of low absorption efficiency and incomplete ammonia collection caused by spray washing of ammonia gas escaping from liquid ammonia storage tanks and liquid ammonia loading areas. It eliminates the environmental pollution and impact on the physical and mental health of employees caused by ammonia gas escaping from liquid ammonia storage tanks, and is conducive to the long-term stable operation of liquid ammonia storage tanks and liquid ammonia loading areas and on-site environmental management.

[0015] This utility model, as an improved ammonia collection, washing, and purification device for liquid ammonia storage tanks, replaces the original ammonia tail gas spray washing and purification with a bubbling dissolution absorption + negative pressure recovery mode for escaping ammonia. It effectively solves the problems of low absorption efficiency and incomplete ammonia collection caused by spray washing of escaping ammonia in liquid ammonia storage tanks and liquid ammonia loading areas. It eliminates the environmental pollution and impact on the physical and mental health of employees caused by ammonia escaping from liquid ammonia storage tank areas, which is conducive to the long-term stable operation of liquid ammonia storage tanks and liquid ammonia loading areas and on-site environmental management, and has good environmental benefits.

[0016] This utility model has a simple structure, reasonable design, low processing and manufacturing cost, is easy to assemble, disassemble and maintain, and is highly practical. It has been put into production and use and has achieved good results. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0018] In the diagram: 2-Ammonia gas collection pipeline; 3-Industrial water supply pipeline; 4-Ammonia gas washing buffer tank; 5-Ammonia gas bubbling pipe; 6-Ammonia gas washing buffer tank venting pipeline; 7-Ammonia water absorption tank; 8-Ammonia gas collection and discharge pipe; 9-Ammonia water absorption tank wastewater discharge pipe; 10-Separation water tank; 11-Separation water tank self-priming pump. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, a liquid ammonia storage tank ammonia collection, washing, and purification device is disclosed. The main body of the liquid ammonia storage tank ammonia collection, washing, and purification device includes an ammonia gas washing buffer tank 4, an ammonia water absorption tank 7, and a separation water tank 10. The ammonia gas washing buffer tank 4 is respectively equipped with an escaping ammonia gas collection pipeline 2 and an industrial water replenishment pipeline 3. The ammonia gas washing buffer tank 4 is connected to the ammonia water absorption tank 7 through an ammonia gas bubbling pipe 5. There are two ammonia gas bubbling pipes 5, one of which extends from the top of the ammonia gas washing buffer tank 4, and the other extends from the middle of the side of the ammonia gas washing buffer tank 4. Two ammonia bubbling pipes 5 extend below the liquid level of the ammonia absorption tank 7. An ammonia washing buffer tank 4 is connected to the ammonia absorption tank 7 via an ammonia washing buffer tank venting line 6. An ammonia escaping gas collection and discharge pipe 8 is provided on the ammonia absorption tank 7. The ammonia absorption tank 7 is connected to the separation tank 10 via the ammonia absorption tank wastewater discharge pipe 9. A separation tank self-priming pump 11 is provided on the separation tank 10. The separation tank self-priming pump 11 is connected to the lower interface of the separation tank 10 and is interlocked with the liquid level of the separation tank 10.

[0021] The ammonia gas collection pipeline 2 is connected to the liquid ammonia loading vapor phase pipeline, and a control valve is installed before it enters the ammonia gas washing buffer tank 4; the industrial water supply pipeline 3 is connected to a fresh water pipeline, and a control valve is installed before it enters the ammonia gas washing buffer tank 4; the ammonia gas washing buffer tank vent pipeline 6 is located at the bottom of the ammonia gas washing buffer tank 4 and is equipped with a control valve; the ammonia gas collection and discharge pipe 8 is connected to the negative pressure system pipeline, and a control valve is installed at the top of the ammonia water absorption tank 7.

[0022] The ammonia washing buffer tank 4 is a horizontal storage tank with a breather valve at the top; the ammonia water absorption tank 7 is a vertical storage tank with a level gauge and a breather valve on its main body; the separation water tank 10 is a horizontal storage tank with a level gauge and a breather valve on its main body.

[0023] The wastewater discharge pipe 9 of the ammonia absorption tank is connected to the upper interface of the separation tank 10 and is equipped with a control valve. The wastewater discharge pipe 9 of the ammonia absorption tank is also equipped with a full flow pipe.

[0024] The components of this utility model cooperate with each other and are connected by control valves to form a unified assembly. The materials of each component are carbon steel and 304 stainless steel.

[0025] The ammonia gas collection pipeline 2 is a DN50 pipe, made of 304 stainless steel, with a wall thickness of 4mm-6mm; the industrial water supply pipeline 3 is a DN50 pipe, made of Q235 carbon steel, with a wall thickness of 4mm-6mm; the ammonia gas washing buffer tank 4 has dimensions of DN2200, L=2500mm, and a volume of 8m³. 3 The material is 304 stainless steel; the ammonia bubbling pipe 5 is a DN50 304 stainless steel pipe; the ammonia washing buffer tank vent line 6 is located below the ammonia washing buffer tank 4, and it is a DN80 304 stainless steel pipe equipped with a control valve; the ammonia water absorption tank 7 is DN2200, H=2500mm, and has a volume of 8m³. 3 The vertical storage tank is made of 304 stainless steel; the ammonia gas collection and discharge pipe 8 is located at the top of the ammonia water absorption tank 7, with a diameter of DN50, made of 304 stainless steel, and a wall thickness of 4mm-6mm.

[0026] Wastewater discharge pipe 9 for ammonia absorption tank is located on one side of ammonia absorption tank 7. It is equipped with a full-flow pipe, the outlet of which is 500mm from the top of ammonia absorption tank 7. The vent pipe is 50-100mm from the bottom of ammonia absorption tank 7 and is equipped with a control valve. The pipe diameter is DN50, the material is 304 stainless steel, and the pipe wall thickness is 4mm-6mm. Separation tank 10 is DN1800, L=4800mm², and has a volume of approximately 10m³. 3The horizontal storage tank is made of 304 stainless steel. The self-priming pump 11 of the separation tank is an auxiliary device of the separation tank 10. Its main function is to send the waste ammonia water after ammonia absorption to the tar ammonia water separation system for purification. The inlet pipe of the self-priming pump has a diameter of DN50, is made of 304 stainless steel, and has a pipe wall thickness of 4mm-6mm. It is connected to the lower interface of the separation tank 10 and is interlocked with the liquid level of the separation tank 10 to realize the function of automatic start of the self-priming pump at high liquid level (1200mm) and automatic stop of the self-priming pump at low liquid level (300mm).

[0027] The working principle of this invention is as follows: Residual tail gas from the ammonia gas collection pipeline 2 is first introduced into the upper part of the ammonia gas washing buffer tank 4, and then exited from the upper part of the ammonia gas washing buffer tank 4 to the bottom of the ammonia water absorption tank 7 through the ammonia gas bubbling pipe 5. The tail gas undergoes bubbling dissolution absorption at the bottom of the ammonia water absorption tank 7, and the ammonia gas is fully absorbed in the ammonia water absorption tank 7. Most of the ammonia gas dissolves directly in the water, and a small amount of non-condensable gases escapes from the water surface of the ammonia water absorption tank 7 and is connected to the negative pressure gas system through the ammonia gas collection and discharge pipe 8. The wastewater that has absorbed ammonia in the ammonia water absorption tank 7 flows to the nearest separation water tank 10. The wastewater is sent to the tar ammonia water separation process for treatment by the separation water tank self-priming pump 11 and the liquid level interlock. The water in the ammonia water absorption tank 7 can be replaced by periodic water replenishment and continuous water replenishment through the industrial water replenishment pipeline 3 according to the loading frequency.

[0028] This invention develops an ammonia collection, washing, and purification device for liquid ammonia storage tanks, which effectively solves the problems of low absorption efficiency and incomplete ammonia collection caused by spray washing of ammonia gas escaping from liquid ammonia storage tanks and liquid ammonia loading areas. It eliminates the environmental pollution and impact on the physical and mental health of employees caused by ammonia gas escaping from liquid ammonia storage tank areas, and is conducive to the long-term stable operation of liquid ammonia storage tanks and liquid ammonia loading areas and on-site environmental management.

Claims

1. A liquid ammonia storage tank ammonia collection, washing, and purification device, characterized in that: The liquid ammonia storage tank ammonia collection, washing and purification device includes an ammonia washing buffer tank (4), an ammonia water absorption tank (7), and a separation water tank (10). The ammonia washing buffer tank (4) is equipped with an escaping ammonia collection pipeline (2) and an industrial water replenishment pipeline (3). The ammonia washing buffer tank (4) is connected to the ammonia water absorption tank (7) through an ammonia bubbling pipe (5). There are two ammonia bubbling pipes (5), one of which is connected from the top of the ammonia washing buffer tank (4), and the other is connected from the middle of the side of the ammonia washing buffer tank (4). The two ammonia bubbling pipes ( 5) Extending below the liquid level of the ammonia absorption tank (7), the ammonia washing buffer tank (4) is connected to the ammonia absorption tank (7) by an ammonia washing buffer tank venting pipeline (6). The ammonia absorption tank (7) is equipped with an ammonia gas collection and discharge pipe (8). The ammonia absorption tank (7) is connected to the separation tank (10) through the ammonia absorption tank wastewater discharge pipe (9). The separation tank (10) is equipped with a separation tank self-priming pump (11). The separation tank self-priming pump (11) is connected to the lower interface of the separation tank (10) and is interlocked with the liquid level of the separation tank (10).

2. The ammonia collection, washing, and purification device for a liquid ammonia storage tank according to claim 1, characterized in that: The ammonia gas collection pipeline (2) is connected to the liquid ammonia loading vapor phase pipeline, and a control valve is provided at the position before entering the ammonia gas washing buffer tank (4); the industrial water replenishment pipeline (3) is connected to the fresh water pipeline, and a control valve is provided at the position before entering the ammonia gas washing buffer tank (4); the ammonia gas washing buffer tank venting pipeline (6) is located at the lower part of the ammonia gas washing buffer tank (4), and a control valve is provided; the ammonia gas collection and discharge pipe (8) is connected to the negative pressure system pipeline, and a control valve is provided at the upper part of the ammonia water absorption tank (7).

3. The ammonia collection, washing, and purification device for a liquid ammonia storage tank according to claim 1 or 2, characterized in that: The ammonia washing buffer tank (4) is a horizontal storage tank with a breather valve at the top; the ammonia absorption tank (7) is a vertical storage tank with a level gauge and a breather valve on its main body; the separation water tank (10) is a horizontal storage tank with a level gauge and a breather valve on its main body.

4. The ammonia collection, washing, and purification device for a liquid ammonia storage tank according to claim 3, characterized in that: The wastewater discharge pipe (9) of the ammonia absorption tank is connected to the upper interface of the separation tank (10) and is equipped with a control valve. The wastewater discharge pipe (9) of the ammonia absorption tank is also equipped with a full flow pipe.

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