A low pressure system vent gas phase ammonia recovery system
By employing a two-stage compression and condensation method, the problem of low-concentration ammonia liquid being difficult to use directly was solved, achieving efficient ammonia recovery and concentration enhancement, reducing equipment burden and energy consumption, and simplifying the processing technology.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHONGQING JIANFENG CHEM
- Filing Date
- 2025-07-09
- Publication Date
- 2026-06-09
AI Technical Summary
In existing ammonia recovery systems, low-concentration ammonia solutions are difficult to use directly and require concentration through complex processes, resulting in high equipment investment, energy consumption, and labor costs.
A two-stage compression and condensation method is used to send ammonia-containing gas into a compressor for two-stage compression, and then use a condensation device to condense and liquefy the ammonia before it enters the absorption tower to contact the absorbent liquid sprayed by the sprinkler device, thereby achieving efficient ammonia recovery.
It increases the concentration of ammonia recovery liquid, reduces equipment burden and energy consumption, simplifies subsequent processing, and lowers production costs.
Smart Images
Figure CN224331849U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of ammonia recovery, and more specifically, to a low-pressure system venting ammonia recovery system. Background Technology
[0002] In many ammonia-related production systems and processes, such as ammonia synthesis, fertilizer manufacturing, and refrigeration cycles, the low-pressure gases emitted during production often contain a certain concentration of ammonia. Direct emission of these ammonia-containing gases not only wastes ammonia resources but also pollutes the atmosphere, causing environmental problems such as smog and acid rain, and poses certain safety hazards. Therefore, ammonia-containing gases must undergo ammonia recovery and subsequent treatment to meet emission standards before being released.
[0003] Currently, the most common industrial method for ammonia recovery is to use an absorption tower to ensure sufficient contact between ammonia-containing gas and the absorbent liquid, thereby recovering the ammonia through the absorbent liquid's solubility properties. To improve absorption efficiency, measures such as increasing the amount of absorbent liquid sprayed and slowing down the gas flow rate are typically employed. However, while these methods can improve the ammonia recovery rate, they result in a low concentration of the ammonia solution after absorption; for example, the concentration of dilute ammonia water may only be 5-15%. Low-concentration ammonia solutions are difficult to use directly and require a series of complex processes such as distillation and rectification for concentration and purification. This undoubtedly increases equipment investment, energy consumption, and labor costs significantly, substantially raising production costs. To address this industry pain point, there is an urgent need to design a more efficient ammonia recovery system. Utility Model Content
[0004] The purpose of this invention is to provide a low-pressure system venting ammonia recovery system that can efficiently recover ammonia from the gas and effectively increase the concentration of ammonia in the recovered liquid.
[0005] This utility model is achieved through the following technical solution: The low-pressure system venting ammonia recovery system of this utility model includes a compressor, a first condensing device connected to a first compression stage of the compressor, a second condensing device connected to a second compression stage of the compressor, a jetting device connected to the outlet end of the second condensing device, an absorption tower, and a pair of water spraying devices disposed inside the absorption tower; one of the water spraying devices is disposed above the other water spraying device; the jetting device is disposed at the lower end inside the absorption tower, and the jetting device is disposed directly below the water spraying device.
[0006] Furthermore, the structure of the first condensing device is the same as that of the second condensing device.
[0007] Further, the first condensation device includes a housing, an air inlet and an air outlet located on the side wall of the housing, a heat exchange tube located inside the housing, a first liquid storage chamber located at the lower end of the housing, a first liquid guide hole located at the upper end of the first liquid storage chamber, a first drain pipe communicating with the lower end of the first liquid storage chamber, and a valve located on the first drain pipe; both ends of the heat exchange tube pass through the side wall of the housing and extend outward; the outlet end of the first stage of the compressor is provided with a first air guide pipe, and the inlet end of the second stage of the compressor is provided with a second air guide pipe; the first air guide pipe is connected to the air inlet of the housing, and the second air guide pipe is connected to the air outlet of the housing.
[0008] Furthermore, the outer wall of the heat exchange tube is provided with multiple fins.
[0009] Furthermore, the lower end of the absorption tower is provided with a second liquid storage chamber, the upper end of the second liquid storage chamber is provided with a plurality of second liquid guiding holes, the lower end of the second liquid storage chamber is connected to a second liquid drain pipe, and a pump body is provided on the second liquid drain pipe; the liquid storage chamber is located below the jet device; the second liquid drain pipe is connected to one end of the heat exchange tube in the first condensation device.
[0010] Furthermore, the compressor's second-stage compression outlet is provided with a third air guide pipe; the third air guide pipe is connected to the air inlet of the second condensing device; the second condensing device's outlet is provided with a fourth air guide pipe, which is connected to the jet device.
[0011] Furthermore, the jet device includes a horizontally arranged, hollow jet plate and a plurality of jet nozzles disposed on the jet plate; the jet plate is connected to the fourth air guide pipe.
[0012] Furthermore, the watering device includes a horizontally arranged, hollow watering plate, a plurality of water nozzles located on the lower side of the watering plate, and a water inlet pipe communicating with the watering plate; the water inlet pipe passes through the side wall of the absorption tower and extends outward.
[0013] Furthermore, the absorption tower includes a first tower body, a second tower body connected to the lower end of the first tower body, and a third drain pipe disposed on the lower side wall of the first tower body; the diameter of the first tower body is larger than the diameter of the second tower body, one of the water spraying devices is disposed in the first tower body, and the other of the water spraying devices is disposed in the second tower body.
[0014] Furthermore, the upper part of the second tower body has a conical structure that is smaller at the top and larger at the bottom.
[0015] The technical solution of this utility model has at least the following advantages and beneficial effects: In the low-pressure system venting phase ammonia recovery system of this utility model, the ammonia-containing gas discharged from the venting system is sent to the compressor for two-stage compression during use. The high-pressure gas after the first stage of compression is discharged into the first condensing device for condensation, where part of the ammonia in the high-pressure gas is condensed and liquefied. The remaining high-pressure gas returns to the compressor for a second stage of compression. The gas after the second stage of compression enters the second condensing device for further condensation, where part of the ammonia in the high-pressure gas is condensed and liquefied. Finally, the remaining high-pressure gas enters the jetting device and is sprayed into the absorption tower. During the gas's ascent, it comes into contact with the absorbent liquid sprayed by the water spraying device, and the ammonia in the gas is absorbed by the absorbent liquid. Finally, the gas containing ultra-low concentration ammonia is discharged from the top of the absorption tower. By compressing the gas with a compressor to increase its pressure, the first and second condensing units can efficiently condense and recover ammonia from the gas. This process also cools the high-temperature gas, reducing the burden on the compressor. Furthermore, the gas temperature is lower when it enters the absorption tower, resulting in higher ammonia absorption efficiency. The entire process does not require a large amount of absorbent, ensuring that the ammonia concentration in the final absorbent remains at a high level. Attached Figure Description
[0016] Figure 1 A schematic diagram of the structure of the low-pressure system venting ammonia recovery system provided in this embodiment of the utility model;
[0017] Figure 2 This is a schematic diagram of the internal structure of the first condensation device provided in an embodiment of the present invention.
[0018] Icons: 10-Compressor, 11-First air guide pipe, 12-Second air guide pipe, 13-Third air guide pipe, 14-Fourth air guide pipe, 20-First condensing device, 21-Box body, 22-Air inlet, 23-Air outlet, 24-Heat exchange tube, 25-First liquid storage chamber, 26-First liquid guide hole, 27-First drain pipe, 28-Second drain pipe, 29-Pump body, 30-Second condensing device, 40-Jet device, 41-Exhaust plate, 42-Jet nozzle, 50-Absorption tower, 51-First tower body, 52-Second tower body, 53-Second liquid storage chamber, 54-Second liquid guide hole, 55-Third drain pipe, 60-Sprinkler device, 61-Sprinkler plate, 62-Sprinkler nozzle, 63-Water inlet pipe. Detailed Implementation
[0019] Example
[0020] The following description, in conjunction with specific embodiments, further illustrates the point, as shown in the appendix. Figure 1 -Appendix Figure 2As shown in the attached diagram, the arrows indicate the flow direction of the gas or liquid. The low-pressure system venting ammonia recovery system of this embodiment includes a compressor 10, a first condensing device 20 connected to a first compression stage of the compressor 10, a second condensing device 30 connected to a second compression stage of the compressor 10, a jetting device 40 connected to the outlet of the second condensing device 30, an absorption tower 50, and a pair of water spraying devices 60 disposed inside the absorption tower 50; one water spraying device 60 is disposed above the other water spraying device 60; the jetting device 40 is disposed at the lower end inside the absorption tower 50, and is disposed directly below the water spraying device 60. Specifically, during operation, the ammonia-containing gas discharged from the venting system is sent to compressor 10 for two-stage compression. The high-pressure gas after the first stage of compression is then discharged into the first condensing unit 20 for condensation, where some of the ammonia in the high-pressure gas is condensed and liquefied. The remaining high-pressure gas returns to compressor 10 for a second stage of compression. After this second stage, the gas enters the second condensing unit 30 for further condensation, where some of the ammonia in the high-pressure gas is condensed and liquefied. Finally, the remaining high-pressure gas enters the jetting device 40 and is sprayed into the absorption tower 50. As the gas rises, it comes into contact with the absorbent liquid sprayed by the water spraying device 60, where the ammonia in the gas is absorbed. Finally, the gas containing ultra-low concentrations of ammonia is discharged from the top of the absorption tower 50. This compression of the gas by compressor 10 increases the gas pressure, enabling the first and second condensing units 20 and 30 to efficiently condense and recover the ammonia in the gas. It also cools the high-temperature gas, reducing the load on compressor 10, and ensures that the gas temperature is lower when it enters the absorption tower 50, resulting in higher ammonia absorption efficiency.
[0021] The structure of the first condensing device 20 in this embodiment is the same as that of the second condensing device 30. The first condensing device 20 includes a housing 21, an air inlet 22 and an air outlet 23 located on the side wall of the housing 21, a heat exchange tube 24 located inside the housing 21, a first liquid storage chamber 25 located at the lower end of the housing 21, a first liquid guide hole 26 located at the upper end of the first liquid storage chamber 25, a first drain pipe 27 connected to the lower end of the first liquid storage chamber 25, and a valve located on the first drain pipe 27; both ends of the heat exchange tube 24 pass through the side wall of the housing 21 and extend outward; the outlet end of the first stage of the compressor 10 is provided with a first air guide pipe 11, and the inlet end of the second stage of the compressor 10 is provided with a second air guide pipe 12; the first air guide pipe 11 is connected to the air inlet 22 of the housing 21, and the second air guide pipe 12 is connected to the air outlet 23 of the housing 21. The outer wall of the heat exchange tube 24 is provided with multiple fins. Specifically, the gas discharged from the venting system enters the compressor 10. After compression, it is sent to the first condenser 20 through the first gas guide pipe 11. After condensation in the first condenser 20, it is discharged through the second gas guide pipe 12 and then enters the second stage of compression in the compressor 10. Low-temperature or room-temperature liquids can be sent to the heat exchange tube 24 for heat exchange before being discharged from the heat exchange tube 24. Ammonia condensed in the housing 21 enters the first liquid storage chamber 25 through the first liquid guide hole 26 for temporary storage. The liquid (high-concentration ammonia water) in the first liquid storage chamber 25 is periodically discharged through the first drain pipe 27.
[0022] In this embodiment, the lower end of the absorption tower 50 is provided with a second liquid storage chamber 53, and the upper end of the second liquid storage chamber 53 is provided with multiple second liquid guide holes 54. The lower end of the second liquid storage chamber 53 is connected to a second drain pipe 28, and a pump body 29 is provided on the second drain pipe 28. The liquid storage chamber is located below the jet device 40. The second drain pipe 28 is connected to one end of the heat exchange tube 24 in the first condensation device 20. Specifically, the gas pressure after the first stage of compression by the compressor 10 is lower than the gas pressure after the second stage of compression. The higher the pressure of ammonia, the lower the temperature required for its condensation. That is, the first stage of compressed gas requires condensate at a lower temperature, while the second stage of compressed gas can be condensed using room temperature water. After the high-pressure gas after the second stage compression is injected into the absorption tower 50 through the jet device 40, the gas pressure suddenly drops, thus absorbing heat from the outside. At this time, the absorbent liquid sprayed from the sprinkler device 60 comes into contact with the gas, and the temperature of the absorbent liquid will drop significantly. The low-temperature absorbent liquid flows into the second liquid storage chamber 53 through the second liquid guide hole 54. The pump body 29 absorbs the low-temperature absorbent liquid in the second liquid storage chamber 53 through the second liquid drain pipe 28 and sends it into the heat exchange tube 24 of the first condensing device 20 to condense and liquefy the ammonia gas in the first condensing device 20. In this way, no additional refrigeration equipment is needed.
[0023] In this embodiment, the compressor 10, after two-stage compression, has a third gas guide pipe 13 at its outlet. The third gas guide pipe 13 is connected to the inlet 22 of the second condensing device 30. A fourth gas guide pipe 14 is provided at the outlet 23 of the second condensing device 30, and the fourth gas guide pipe 14 is connected to the jetting device 40. Specifically, the high-pressure gas after two-stage compression by the compressor 10 is sent into the second condensing device 30 through the third gas guide pipe 13. After some ammonia gas is condensed, the remaining gas is sent into the jetting device 40 through the fourth gas guide pipe 14, and then enters the absorption tower 50 for final absorption.
[0024] The jetting device 40 in this embodiment includes a horizontally arranged, hollow jetting plate and a plurality of jet nozzles 42 disposed on the jetting plate; the jetting plate is connected to the fourth gas guide pipe 14. Specifically, after the high-pressure gas enters the jetting plate, it is uniformly sprayed into the absorption tower 50 from the jet nozzles 42 on the jetting plate.
[0025] The water spraying device 60 in this embodiment includes a horizontally arranged, hollow water spray plate 61, a plurality of spray nozzles 62 disposed on the lower side of the water spray plate 61, and a water inlet pipe 63 communicating with the water spray plate 61; the water inlet pipe 63 passes through the side wall of the absorption tower 50 and extends outward. Specifically, the absorbent liquid is sent into the water spray plate 61 through the water inlet pipe 63, and then evenly sprayed into the absorption tower 50 from the spray nozzles 62 on the water spray plate 61, contacting the rising gas and absorbing ammonia in the gas.
[0026] The absorption tower 50 in this embodiment includes a first tower body 51, a second tower body 52 connected to the lower end of the first tower body 51, and a third drain pipe 55 disposed on the lower side wall of the first tower body 51. The diameter of the first tower body 51 is larger than the diameter of the second tower body 52. One water spraying device 60 is disposed in the first tower body 51, and another water spraying device 60 is disposed in the second tower body 52. The upper part of the second tower body 52 has a conical structure that is smaller at the top and larger at the bottom. Specifically, since only the absorbent sprayed by the water spraying device 60 in the second tower body 52 will be sufficiently cooled, while the temperature of the absorbent sprayed by the water spraying device 60 in the first tower body 51 will not be greatly affected, most of the absorbent sprayed from the first tower body 51 will flow to the lower side wall of the first tower body 51 and be discharged through the third drain pipe 55. This can minimize the possibility of the room temperature absorbent in the first tower body 51 entering the second storage chamber 53 and raising the temperature of the absorbent in the second storage chamber 53.
[0027] In summary, the low-pressure system venting phase ammonia recovery system of this embodiment, during use, sends the ammonia-containing gas discharged from the venting system into the compressor 10 for two-stage compression. The high-pressure gas after the first stage compression in the compressor 10 is discharged into the first condensing device 20 for condensation, where part of the ammonia in the high-pressure gas is condensed and liquefied. The remaining high-pressure gas returns to the compressor 10 for a second stage compression. The gas after the second stage compression enters the second condensing device 30 for further condensation, where part of the ammonia in the high-pressure gas is condensed and liquefied. Finally, the remaining high-pressure gas enters the jetting device 40 and is sprayed into the absorption tower 50. During the gas's ascent, it comes into contact with the absorbent liquid sprayed by the water spraying device 60, and the ammonia in the gas is absorbed by the absorbent liquid. Finally, the gas containing ultra-low concentration ammonia is discharged from the top of the absorption tower 50. By compressing the gas with compressor 10, the gas pressure is increased, which enables the first condenser 20 and the second condenser 30 to efficiently condense and recover ammonia from the gas. It also cools the high-temperature gas, reduces the burden on compressor 10, and makes the gas temperature lower when it enters the absorption tower 50, resulting in higher ammonia absorption efficiency.
[0028] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A low-pressure system for recovering ammonia from the vent phase, characterized in that: The device includes a compressor (10), a first condensing device (20) connected to a first compression section of the compressor (10), a second condensing device (30) connected to a second compression section of the compressor (10), a jetting device (40) connected to the outlet of the second condensing device (30), an absorption tower (50), and a pair of sprinkler devices (60) disposed inside the absorption tower (50); one of the sprinkler devices (60) is disposed above the other sprinkler device (60). The jetting device (40) is located at the lower end of the inside of the absorption tower (50), and the jetting device (40) is located directly below the water spraying device (60).
2. The low-pressure system venting ammonia recovery system according to claim 1, characterized in that: The structure of the first condensing device (20) is the same as that of the second condensing device (30).
3. The low-pressure system venting ammonia recovery system according to claim 2, characterized in that: The first condensation device (20) includes a housing (21), an air inlet (22) and an air outlet (23) provided on the side wall of the housing (21), a heat exchange tube (24) provided in the housing (21), a first liquid storage chamber (25) provided at the lower end of the housing (21), a first liquid guide hole (26) provided at the upper end of the first liquid storage chamber (25), a first drain pipe (27) communicating with the lower end of the first liquid storage chamber (25), and a valve provided on the first drain pipe (27); Both ends of the heat exchange tube (24) pass through the side wall of the box (21) and extend outward; the first air outlet of the compressor (10) is provided with a first air guide pipe (11), and the second air inlet of the compressor (10) is provided with a second air guide pipe (12); the first air guide pipe (11) is connected to the air inlet (22) of the box (21), and the second air guide pipe (12) is connected to the air outlet (23) of the box (21).
4. The low-pressure system venting ammonia recovery system according to claim 3, characterized in that: The heat exchange tube (24) has multiple fins on its outer wall.
5. The low-pressure system venting ammonia recovery system according to claim 3, characterized in that: The absorption tower (50) has a second liquid storage chamber (53) at the lower end, and a plurality of second liquid guide holes (54) are opened at the upper end of the second liquid storage chamber (53). The lower end of the second liquid storage chamber (53) is connected to a second drain pipe (28), and a pump body (29) is provided on the second drain pipe (28). The liquid storage chamber is located below the jet device (40); the second drain pipe (28) is connected to one end of the heat exchange tube (24) in the first condenser (20).
6. The low-pressure system venting ammonia recovery system according to claim 3, characterized in that: The compressor (10) is provided with a third air guide pipe (13) at the outlet of the two-stage compression; the third air guide pipe (13) is connected to the air inlet (22) of the second condensing device (30); The second condenser (30) has a fourth air guide pipe (14) at its air outlet (23), and the fourth air guide pipe (14) is connected to the jet device (40).
7. The low-pressure system venting ammonia recovery system according to claim 6, characterized in that: The jet device (40) includes a horizontally arranged and hollow jet plate, and a plurality of jet nozzles (42) disposed on the jet plate; The jet plate is connected to the fourth air duct (14).
8. The low-pressure system venting ammonia recovery system according to claim 3, characterized in that: The water spraying device (60) includes a horizontally arranged and hollow water spraying plate (61), a plurality of water spray nozzles (62) located on the lower side of the water spraying plate (61), and a water inlet pipe (63) communicating with the water spraying plate (61); the water inlet pipe (63) passes through the side wall of the absorption tower (50) and extends outward.
9. The low-pressure system venting ammonia recovery system according to claim 1, characterized in that: The absorption tower (50) includes a first tower body (51), a second tower body (52) connected to the lower end of the first tower body (51), and a third drain pipe (55) disposed on the side wall of the lower end of the first tower body (51). The diameter of the first tower body (51) is larger than the diameter of the second tower body (52). One of the sprinkler devices (60) is located in the first tower body (51), and the other sprinkler device (60) is located in the second tower body (52).
10. The low-pressure system venting ammonia recovery system according to claim 9, characterized in that: The upper part of the second tower body (52) is a conical structure with a smaller top and a larger bottom.