Ammonia recovery system and ammonia recovery method

Abstract

The present invention discloses an ammonia recovery system and an ammonia recovery method, comprising an ammonia source tank, a pressure sensor is arranged on the top of the ammonia source tank, a main liquid outlet pipeline is connected to the bottom of the ammonia source tank; and an absorption tower, the bottom of the absorption tower is connected to the main liquid outlet pipeline. The present invention can effectively solve the problems existing in the prior art, by arranging an electric flow regulating valve on the main liquid outlet pipeline of the ammonia source tank, and adjusting its opening by feedback signal of a liquid level sensor, so as to accurately control the flow of ammonia water to the absorption tower, ensure that the ammonia water level in the absorption tower is within a set range, and realize efficient ammonia absorption. In terms of the recovery liquid storage tank, a liquid level meter is arranged for monitoring, and the safety and stability of the recovery liquid storage process are ensured by reasonably setting the opening and closing sequence of each valve. At the same time, the air in the absorption tower is extracted by a vacuum pump before the ammonia absorption operation is performed, and a balance pipeline is arranged to maintain air pressure balance, thereby improving the efficiency and stability of ammonia recovery.

Description

Technical Field

[0001] The present invention relates to the field of ammonia recovery, and in particular to an ammonia recovery system and an ammonia recovery method. Background Art

[0002] Ammonia is widely used in many industrial processes, such as chemical production, agricultural fertilizer manufacturing, refrigeration and other industries. However, the emission of ammonia not only causes a waste of resources, but also has a pungent odor and is harmful to the environment and human health. For example, ammonia can react with acidic pollutants in the atmosphere to form particulate matter, affecting air quality. Excessive ammonia emissions into water bodies will change the pH of the water body and affect the survival of aquatic organisms. Therefore, the recovery of ammonia has important economic and environmental significance.

[0003] At present, there are many technical solutions for ammonia recovery. For example, some existing technologies use a simple water washing method to recover ammonia, that is, the ammonia-containing tail gas is passed through a water absorption device, and the ammonia is dissolved in the water to form ammonia water. However, this method has some obvious disadvantages. On the one hand, the absorption efficiency of the water washing method is relatively low, because the absorption capacity of water for ammonia is limited, and in actual operation, due to insufficient gas-liquid contact, a lot of ammonia cannot be effectively absorbed and is directly discharged into the environment. On the other hand, this method lacks precise control of the absorption process, such as the inability to accurately adjust the flow and circulation of the absorption liquid according to the actual amount of ammonia, resulting in unstable absorption effect. Summary of the invention

[0004] The object of the present invention is to provide an ammonia recovery system and an ammonia recovery method to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An ammonia recovery system comprising

[0007] An ammonia source tank, wherein a pressure sensor is arranged on the top of the ammonia source tank and a main liquid outlet pipe is connected to the bottom of the ammonia source tank;

[0008] An absorption tower, the bottom of which is connected to a main liquid outlet pipeline, and a gas phase pipeline is arranged at the top of the absorption tower;

[0009] A recovery liquid storage tank, the top of which is connected to the top of the absorption tower through a balance pipe, and the bottom of which is connected to an auxiliary liquid outlet pipe.

[0010] The present invention also includes a recovery liquid pipeline, which is connected to the bottom end of the absorption tower, and the other end of the recovery liquid pipeline is arranged at the top of the absorption tower. A circulation pump is arranged in the middle of the recovery liquid pipeline.

[0011] In the present invention, a liquid level observation window and a liquid level sensor are arranged on the side of the absorption tower, the liquid level sensor is connected to a controller, and the controller is electrically connected to a circulation pump.

[0012] In the present invention, a vacuum pipe is further provided at the upper end of the absorption tower, and a vacuum pump is connected to the top of the vacuum pipe.

[0013] In the present invention, an electric flow regulating valve is arranged at one end of the main liquid outlet pipeline close to the ammonia source tank, and a manual stop valve is arranged at one end of the main liquid outlet pipeline close to the absorption tower.

[0014] In the present invention, a liquid level gauge is also arranged on the side of the recovery liquid storage tank, a secondary liquid outlet pipe is connected to the bottom end of the recovery liquid storage tank, and a one-way valve is arranged in the middle of the secondary liquid outlet pipe.

[0015] An ammonia recovery method comprises the following steps:

[0016] Step 1: Check whether the pressure sensor, manual shut-off valve, and electric flow control valve of the ammonia source tank are working properly and whether there is no leakage in the ammonia source tank; check the filling of the absorption material inside the absorption tower, and check whether the liquid level gauge of the recovery liquid storage tank is operating normally; check the electrical connection and mechanical parts of the circulation pump and vacuum pump to ensure normal startup; according to the expected ammonia volume of the ammonia emission source, set the initial opening of the electric flow control valve to 10% through the controller, and open the connecting valve between the gas phase pipeline of the absorption tower and the ammonia emission source;

[0017] Step 2: Start the vacuum pump, extract the air in the absorption tower through the vacuum pipe, observe the liquid level observation window and liquid level sensor of the absorption tower, and turn off the vacuum pump when the liquid level sensor shows that the liquid level begins to rise; open the manual stop valve on the main liquid outlet pipe of the ammonia source tank, and the controller adjusts the opening of the electric flow control valve according to the feedback signal of the liquid level sensor so that the ammonia water in the ammonia source tank enters the bottom of the absorption tower at an appropriate flow rate. At the same time, start the circulation pump to transport the ammonia water at the bottom of the absorption tower to the top of the absorption tower for circulation. According to the monitoring results of the liquid level sensor and the liquid level observation window, when the liquid level reaches the set upper limit value, such as 80%, Reduce the opening of the electric flow control valve. When the liquid level reaches the set lower limit value, such as 20%, increase the opening of the electric flow control valve. When the liquid level in the absorption tower reaches the inlet level of the recovery liquid storage tank, such as 90%, close the electric flow control valve and the circulation pump, open the valve on the balance pipe between the air inlet at the top of the recovery liquid storage tank and the top of the absorption tower to balance the air pressure, open the valve on the recovery liquid pipeline between the bottom discharge port of the absorption tower and the recovery liquid storage tank to allow ammonia water to flow into the recovery liquid storage tank, observe the liquid level gauge of the recovery liquid storage tank, and close the valve on the recovery liquid pipeline when the liquid level reaches the set upper limit value, such as 95%;

[0018] Step three, close the connecting valve between the gas phase pipeline of the absorption tower and the ammonia emission source, close the one-way valve on the secondary outlet pipeline of the recovery liquid storage tank, close the manual stop valve on the main outlet pipeline of the ammonia source tank, and inspect the entire system to clean up any ammonia leaks or residual ammonia.

[0019] In the present invention, in step S2, the appropriate flow rate refers to the flow rate that can keep the ammonia water level in the absorption tower within a set range, and the set range is between 20% of the lower limit of the liquid level and 80% of the upper limit of the liquid level.

[0020] In the present invention, in step S2, the liquid inlet level is 90%, and the set upper limit value of the liquid level meter is 95%.

[0021] In the present invention, in step S2, by observing that the liquid level sensor shows that the liquid level begins to rise, it is determined that the air is basically evacuated and ammonia begins to be absorbed to form ammonia water.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The ammonia recovery system and ammonia recovery method provided by the present invention can effectively solve the problems existing in the prior art. By arranging an electric flow control valve on the main liquid outlet pipe of the ammonia source tank and adjusting its opening by the feedback signal of the liquid level sensor, the flow rate of ammonia water to the absorption tower is accurately controlled to ensure that the ammonia water level in the absorption tower is within the set range, thereby achieving efficient ammonia absorption. In terms of the recovery liquid storage tank, a liquid level meter is set for monitoring, and the safety and stability of the recovery liquid storage process are guaranteed by reasonably setting the opening and closing sequence of each valve. At the same time, the air in the absorption tower is extracted by a vacuum pump before the ammonia absorption operation is performed, and a balancing pipe is set to maintain air pressure balance, thereby improving the efficiency and stability of ammonia recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the overall structure of an ammonia recovery system of the present invention.

[0025] In the figure: 1. Ammonia source tank; 2. Pressure sensor; 3. Main liquid outlet pipeline; 4. Manual stop valve; 5. Electric flow control valve; 6. Absorption tower; 7. Gas phase pipeline; 8. Liquid level observation window; 9. Liquid level sensor; 10. Recovery liquid pipeline; 11. Recovery liquid storage tank; 12. Balance pipeline; 13. Liquid level meter; 14. Auxiliary liquid outlet pipeline; 15. Check valve; 16. Circulation pump; 17. Controller; 18. Vacuum pump; 19. Vacuum pipeline. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, the present invention provides a technical solution:

[0028] An ammonia recovery system includes an ammonia source tank 1, a pressure sensor 2 is arranged on the top of the ammonia source tank 1, and a main liquid outlet pipeline 3 is connected to the bottom of the ammonia source tank 1; an absorption tower 6, the bottom of the absorption tower 6 is connected to the main liquid outlet pipeline 3, and a gas phase pipeline 7 is arranged on the top of the absorption tower 6; a recovery liquid storage tank 11, the top of the recovery liquid storage tank 11 is connected to the top of the absorption tower 6 through a balance pipeline 12, and a secondary liquid outlet pipeline 14 is connected to the bottom of the recovery liquid storage tank 11; and also includes a recovery liquid pipeline 10, the bottom end of the absorption tower 6 is connected to the recovery liquid pipeline 10, the other end of the recovery liquid pipeline 10 is arranged at the top of the absorption tower 6, and a gas phase pipeline 7 is arranged in the middle of the recovery liquid pipeline 10. A circulating pump 16; a liquid level observation window 8 and a liquid level sensor 9 are arranged on the side of the absorption tower 6, the liquid level sensor 9 is connected to a controller 17, and the controller 17 is electrically connected to the circulating pump 16; a vacuum pipe 19 is also arranged at the upper end of the absorption tower 6, and a vacuum pump 18 is connected to the top of the vacuum pipe 19; an electric flow regulating valve 5 is arranged at one end of the main liquid outlet pipe 3 close to the ammonia source tank 1, and a manual stop valve 4 is arranged at one end of the main liquid outlet pipe 3 close to the absorption tower 6; a liquid level meter 13 is also arranged on the side of the recovery liquid storage tank 11, and an auxiliary liquid outlet pipe 14 is connected to the bottom end of the recovery liquid storage tank 11, and a one-way valve 15 is arranged in the middle of the auxiliary liquid outlet pipe 14.

[0029] An ammonia recovery method comprises the following steps:

[0030] Step 1: Check whether the pressure sensor 2, manual stop valve 4, and electric flow control valve 5 of the ammonia source tank 1 are working properly and whether there is no leakage in the ammonia source tank 1; check the filling of the absorption material inside the absorption tower 6, and check whether the liquid level gauge 13 of the recovery liquid storage tank 11 is operating normally; check the electrical connection and mechanical parts of the circulation pump 16 and the vacuum pump 18 to ensure normal startup; according to the expected ammonia amount of the ammonia emission source, set the initial opening of the electric flow control valve 5 to 10% through the controller 17, and open the connection valve between the gas phase pipeline 7 of the absorption tower 6 and the ammonia emission source;

[0031] Step 2, start the vacuum pump 18, extract the air in the absorption tower 6 through the vacuum pipe 19, observe the liquid level observation window 8 and the liquid level sensor 9 of the absorption tower 6, and turn off the vacuum pump 18 when the liquid level sensor 9 shows that the liquid level begins to rise; open the manual stop valve 4 on the main liquid outlet pipe 3 of the ammonia source tank 1, and the controller 17 adjusts the opening of the electric flow control valve 5 according to the feedback signal of the liquid level sensor 9 so that the ammonia water in the ammonia source tank 1 enters the bottom of the absorption tower 6 at an appropriate flow rate. At the same time, start the circulation pump 16 to transport the ammonia water at the bottom of the absorption tower 6 to the top of the absorption tower 6 for circulation. According to the monitoring results of the liquid level sensor 9 and the liquid level observation window 8, when the liquid level reaches the set upper limit value, such as 80%, Reduce the opening of the electric flow regulating valve 5, and increase the opening of the electric flow regulating valve 5 when the liquid level reaches the set lower limit value, such as 20%; when the liquid level in the absorption tower 6 reaches the inlet liquid level of the recovery liquid storage tank 11, such as 90%, close the electric flow regulating valve 5 and the circulation pump 16, open the valve on the air inlet at the top of the recovery liquid storage tank 11 and the balance pipe 12 at the top of the absorption tower 6 to balance the air pressure, open the valve on the recovery liquid pipe 10 between the bottom discharge port of the absorption tower 6 and the recovery liquid storage tank 11 to allow ammonia water to flow into the recovery liquid storage tank 11, observe the liquid level meter 13 of the recovery liquid storage tank 11, and close the valve on the recovery liquid pipe 10 when the liquid level reaches the set upper limit value, such as 95%;

[0032] Step three, close the connecting valve between the gas phase pipeline 7 of the absorption tower 6 and the ammonia emission source, close the one-way valve 15 on the secondary outlet pipeline 14 of the recovery liquid storage tank 11, close the manual stop valve 4 on the main outlet pipeline 3 of the ammonia source tank 1, and check the entire system to clean up the ammonia leakage points or residual ammonia.

[0033] In this embodiment, in step S2, the appropriate flow rate refers to the flow rate that can keep the ammonia water level in the absorption tower 6 within a set range, and the set range is between 20% of the lower limit of the liquid level and 80% of the upper limit of the liquid level.

[0034] In this embodiment, in step S2, the liquid inlet level is 90%, and the set upper limit value of the liquid level meter 13 is 95%.

[0035] In this embodiment, in step S2, by observing that the liquid level sensor 9 shows that the liquid level begins to rise, it is determined that the air is basically evacuated and ammonia begins to be absorbed to form ammonia water.

[0036] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ammonia recovery system, characterized in that: include An ammonia source tank (1), wherein a pressure sensor (2) is arranged on the top of the ammonia source tank (1), and a main liquid outlet pipe (3) is connected to the bottom of the ammonia source tank (1); An absorption tower (6), wherein the bottom of the absorption tower (6) is connected to the main liquid outlet pipeline (3), and a gas phase pipeline (7) is arranged at the top of the absorption tower (6); A recovery liquid storage tank (11), the top of which is connected to the top of the absorption tower (6) via a balance pipe (12), and the bottom of which is connected to a secondary liquid outlet pipe (14).

2. An ammonia recovery system according to claim 1, characterized in that: It also comprises a recovery liquid pipeline (10), which is connected to the bottom end of the absorption tower (6), the other end of the recovery liquid pipeline (10) is arranged at the top end of the absorption tower (6), and a circulation pump (16) is arranged in the middle of the recovery liquid pipeline (10).

3. An ammonia recovery system according to claim 2, characterized in that: A liquid level observation window (8) and a liquid level sensor (9) are provided on the side of the absorption tower (6); the liquid level sensor (9) is connected to a controller (17); and the controller (17) is electrically connected to a circulation pump (16).

4. An ammonia recovery system according to claim 3, characterized in that: A vacuum pipe (19) is also provided at the upper end of the absorption tower (6), and a vacuum pump (18) is connected to the top of the vacuum pipe (19).

5. An ammonia recovery system according to claim 4, characterized in that: An electric flow regulating valve (5) is provided at one end of the main liquid outlet pipeline (3) close to the ammonia source tank (1), and a manual stop valve (4) is provided at one end of the main liquid outlet pipeline (3) close to the absorption tower (6).

6. An ammonia recovery system according to claim 1, characterized in that: A liquid level meter (13) is also provided on the side of the recovery liquid storage tank (11), a secondary liquid outlet pipeline (14) is connected to the bottom end of the recovery liquid storage tank (11), and a one-way valve (15) is provided in the middle of the secondary liquid outlet pipeline (14).

7. An ammonia recovery method, characterized in that: The following steps are involved: Step 1: Check whether the pressure sensor (2), manual stop valve (4), and electric flow control valve (5) of the ammonia source tank (1) are working properly and whether the ammonia source tank (1) is leaking; check the filling of the absorption material inside the absorption tower (6), and check whether the liquid level gauge (13) of the recovery liquid storage tank (11) is working normally; check the electrical connection and mechanical parts of the circulation pump (16) and the vacuum pump (18) to ensure normal startup; According to the estimated ammonia amount of the ammonia emission source, the controller (17) sets the initial opening of the electric flow control valve (5) to 10%, and opens the connection valve between the gas phase pipeline (7) of the absorption tower (6) and the ammonia emission source; Step 2: Start the vacuum pump (18), extract the air in the absorption tower (6) through the vacuum pipe (19), observe the liquid level observation window (8) and the liquid level sensor (9) of the absorption tower (6), and turn off the vacuum pump (18) when the liquid level sensor (9) shows that the liquid level starts to rise; open the manual stop valve (4) on the main liquid outlet pipe (3) of the ammonia source tank (1), and the controller (17) adjusts the opening of the electric flow control valve (5) according to the feedback signal of the liquid level sensor (9) so that the ammonia water in the ammonia source tank (1) enters the bottom of the absorption tower (6) at an appropriate flow rate. At the same time, start the circulation pump (16) to transport the ammonia water at the bottom of the absorption tower (6) to the top of the absorption tower (6) for circulation. According to the monitoring results of the liquid level sensor (9) and the liquid level observation window (8), when the liquid level reaches the set upper limit value When the liquid level reaches 80%, the opening of the electric flow regulating valve (5) is reduced; when the liquid level reaches a set lower limit value, such as 20%, the opening of the electric flow regulating valve (5) is increased; when the liquid level in the absorption tower (6) reaches the inlet liquid level of the recovery liquid storage tank (11), such as 90%, the electric flow regulating valve (5) and the circulation pump (16) are closed, the valves on the air inlet at the top of the recovery liquid storage tank (11) and the balance pipe (12) at the top of the absorption tower (6) are opened to balance the air pressure, the valve on the recovery liquid pipe (10) between the bottom discharge port of the absorption tower (6) and the recovery liquid storage tank (11) is opened to allow ammonia water to flow into the recovery liquid storage tank (11), the liquid level gauge (13) of the recovery liquid storage tank (11) is observed, and when the liquid level reaches a set upper limit value, such as 95%, the valve on the recovery liquid pipe (10) is closed; Step three, close the connecting valve between the gas phase pipeline (7) of the absorption tower (6) and the ammonia emission source, close the one-way valve (15) on the secondary outlet pipeline (14) of the recovery liquid storage tank (11), close the manual stop valve (4) on the main outlet pipeline (3) of the ammonia source tank (1), and check the entire system to clean up any ammonia leaks or residual ammonia.

8. An ammonia recovery method according to claim 7, characterized in that: In step S2, the appropriate flow rate refers to a flow rate that can keep the ammonia water level in the absorption tower (6) within a set range, and the set range is between 20% of the lower limit of the liquid level and 80% of the upper limit of the liquid level.

9. An ammonia recovery method according to claim 7, characterized in that: In step S2, the liquid inlet level is 90%, and the set upper limit value of the liquid level meter (13) is 95%.

10. An ammonia recovery method according to claim 7, characterized in that: In step S2, by observing that the liquid level sensor (9) shows that the liquid level begins to rise, it is determined that the air is basically evacuated and ammonia begins to be absorbed to form ammonia water.

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