Ammonia recovery system for purge gas

Abstract

The ammonia recovery system for purge gas comprises a heat exchange separation mechanism, a nitrogen circulation mechanism and an expansion machine, the nitrogen circulation mechanism comprises a nitrogen pipeline and a compressor, and nitrogen, refrigerated by the cold end of the expansion machine, in the nitrogen pipeline passes through the heat exchange separation mechanism and then passes through the compressor. The compressor is installed on the nitrogen pipeline and drives nitrogen in the nitrogen pipeline to sequentially flow through the cold end of the expansion machine, the heat exchange separation mechanism and the hot end of the expansion machine and then return to the compressor to form nitrogen circulation. The heat exchange separation mechanism is connected with the purge gas, and the heat exchange separation mechanism takes nitrogen output by the cold end of the expansion machine as a cold source to cool the purge gas, so that ammonia gas in the purge gas is liquefied into liquid ammonia, and the liquefied liquid ammonia in the purge gas is separated and output. According to the technical scheme, ammonia gas is separated and recycled in a cooling and liquefying mode, gaseous ammonia in the purge gas can be effectively recycled, resource waste is reduced, and pollution of the purge gas can be relieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to synthetic ammonia release gas recovery gas ammonia technology field especially relates to a kind of ammonia recovery system for release gas. BACKGROUND

[0002] At present, when discharging release gas, due to the doping gaseous ammonia in release gas, direct venting causes resource waste, and at the same time, it causes certain influence to environment. How to recover the gaseous ammonia doped in release gas and reduce the influence of release gas on environment is a problem to be solved urgently when discharging release gas. SUMMARY

[0003] In view of the above problems existing in the prior art, the purpose of the utility model embodiment is to provide a kind of ammonia recovery system for release gas.

[0004] The technical scheme adopted in the utility model embodiment is a kind of ammonia recovery system for release gas, including heat exchange separation mechanism, nitrogen circulation mechanism and expander, the nitrogen circulation mechanism includes nitrogen pipeline and compressor, the expander has hot end and cold end, the nitrogen pipeline passes through the hot end and cold end of expander, nitrogen after being cooled by the cold end of expander in the nitrogen pipeline passes through heat exchange separation mechanism, the compressor is installed on nitrogen pipeline, the compressor drives nitrogen in nitrogen pipeline to flow through expander cold end, heat exchange separation mechanism and expander hot end in turn and then returns to compressor to form nitrogen circulation;

[0005] The heat exchange separation mechanism accesses release gas, and the heat exchange separation mechanism cools release gas with nitrogen output by the cold end of expander as cold source, so that ammonia in release gas is liquefied as liquid ammonia, so that the liquefied liquid ammonia in release gas is separated and output.

[0006] Further, the heat exchange separation mechanism includes first heat exchanger, the first heat exchanger has first pipeline, second pipeline and third pipeline, the first pipeline is connected to nitrogen pipeline in series, the first pipeline is located downstream of expander cold end, the input end of second pipeline accesses release gas, and the output end of second pipeline is connected with first separator, the first separator separates gas-liquid from second pipeline input, the first separator has gas phase output end and liquid phase output end, the gas phase output end of first separator discharges gas, the liquid phase output end of first separator is connected with storage tank, the liquid phase output end of first separator outputs liquid ammonia to storage tank, the input end of third pipeline is connected with storage tank, the storage tank inputs liquid ammonia to third pipeline, and liquid ammonia is discharged after being gasified and absorbing heat in third pipeline.

[0007] Further, the heat exchange separation mechanism further comprises a second heat exchanger, the second heat exchanger is provided with a fourth pipeline, a fifth pipeline and a sixth pipeline, the fourth pipeline is connected to the nitrogen pipeline in series, the fourth pipeline is located downstream of the cold end of the expander, and the fourth pipeline is located upstream of the first pipeline, an input end of the fifth pipeline is connected to a gas phase output end of the first separator, so as to guide the gas into the fifth pipeline for further cooling and liquefaction, an output end of the fifth pipeline is connected to a second separator, the second separator is provided with a gas phase output end and a liquid phase output end, the liquid phase output end of the second separator is connected to the storage tank, and the gas phase output end of the second separator is connected to an input end of the sixth pipeline, and an output end of the sixth pipeline is used for discharging residual gas, and the sixth pipeline uses the residual gas as a supplementary cooling source of the second heat exchanger.

[0008] Further, the heat exchange separation mechanism further comprises a third heat exchanger, the third heat exchanger is provided with a seventh pipeline and an eighth pipeline, the seventh pipeline is connected to the nitrogen pipeline in series, and the seventh pipeline is located downstream of the first pipeline, and an input end of the eighth pipeline is connected to an output end of the third pipeline, and residual liquid ammonia in the eighth pipeline is discharged after being gasified by heat absorption.

[0009] Further, the third heat exchanger is further provided with a ninth pipeline, the ninth pipeline is connected to the nitrogen pipeline in series, the ninth pipeline is located upstream of the cold end of the expander, and the ninth pipeline is located downstream of the hot end of the expander.

[0010] Further, the nitrogen circulation mechanism further comprises a branch pipeline, an input end of the branch pipeline is connected to the nitrogen pipeline upstream of the cold end of the expander, and an output end of the branch pipeline is connected to the nitrogen pipeline at the hot end of the expander, the branch pipeline passes through the bearing of the expander, so that the nitrogen in the branch pipeline flows through the bearing of the expander.

[0011] Further, a valve and a filter are arranged on the branch pipeline, and the filter is located upstream of the bearing of the expander.

[0012] Further, the nitrogen pipeline is connected with a gas discharge pipeline, and the gas discharge pipeline is provided with a valve.

[0013] Compared with the prior art, the ammonia recovery system for the vent gas disclosed by the utility model recovers ammonia gas in the vent gas by the cooling and liquefaction mode, can effectively recover the gaseous ammonia in the vent gas, reduces the resource waste, and can reduce the pollution of the vent gas.

[0014] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, rather than for limiting the utility model.

[0015] The foregoing general description and the following detailed description of various implementations or examples of the technology described in the utility model are not comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF DRAWINGS

[0016] In the drawings, which are not necessarily drawn to scale, like numerals describe similar components throughout the several views. Like numerals having different letter suffixes can represent different instances of the components. The drawings illustrate generally, by way of example, various embodiments of the present inventive subject matter and are not intended to limit the present inventive subject matter in any way. In the drawings: the same elements have the same reference numbers. Such embodiments are illustrative rather than limiting of the present inventive subject matter.

[0017] Figure 1 is a schematic view of an embodiment of the present inventive subject matter. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the embodiments of the present inventive subject matter clearer, the technical solutions of the embodiments of the present inventive subject matter will be described clearly and completely below with reference to the drawings of the embodiments of the present inventive subject matter. Obviously, the described embodiments are some, but not all, of the embodiments of the present inventive subject matter. Based on the described embodiments of the present inventive subject matter, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the scope of the present inventive subject matter.

[0019] Unless otherwise defined, technical terms or scientific terms used in the present inventive subject matter shall have the ordinary meanings as understood by one of ordinary skill in the art to which this present inventive subject matter pertains. The words "first", "second" and similar words do not necessarily denote any order, quantity, or importance, but are used to distinguish one element from another, and the terms "comprising", "including", "containing", "having" and the like, are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. The words "connected", "coupled", or the like, are not necessarily limited to a physical or mechanical connection or linkage to described associated parties and can include an electrical connection, whether direct or indirect. The words "upper", "lower", "left", "right" and the like, are used for description only and not as limitations to the scope of the present inventive subject matter.

[0020] In order to keep the following description of the embodiments of the present inventive subject matter clear and concise, detailed descriptions of known functions and structures incorporated herein will be omitted.

[0021] Reference Figure 1This utility model provides an ammonia recovery system for purge gas, including a heat exchange separation mechanism 1, a nitrogen circulation mechanism, and an expander 2. The nitrogen circulation mechanism includes a nitrogen pipeline 3 and a compressor 4. The expander 2 has a hot end and a cold end. The nitrogen pipeline 3 passes through the hot end and the cold end of the expander 2. The nitrogen gas in the nitrogen pipeline 3, after being cooled by the cold end of the expander 2, passes through the heat exchange separation mechanism 1. The compressor 4 is installed on the nitrogen pipeline 3. The compressor 4 drives the nitrogen gas in the nitrogen pipeline 3 to flow sequentially through the cold end of the expander 2, the heat exchange separation mechanism 1, and the hot end of the expander 2 before returning to the compressor 4 to form a nitrogen circulation.

[0022] The heat exchange separation mechanism 1 is connected to the purge gas. The mechanism uses nitrogen output from the cold end of the expander 2 as a cold source to cool the purge gas, liquefying the ammonia in the purge gas into liquid ammonia, thereby separating and outputting the liquefied liquid ammonia. This technical solution separates and recovers ammonia through cooling liquefaction, effectively recovering gaseous ammonia from the purge gas, reducing resource waste, and mitigating pollution from the purge gas. The gaseous ammonia in the purge gas liquefies into liquid ammonia after cooling.

[0023] In some embodiments, the heat exchange separation mechanism 1 includes a first heat exchanger 5, which has a first pipe 51, a second pipe 52, and a third pipe 53. The first pipe 51 is connected in series to the nitrogen pipe 3 and is located downstream of the cold end of the expander 2. The input end of the second pipe 52 is connected to the purge gas, and the output end of the second pipe 52 is connected to a first separator 6. The first separator 6 separates the gas and liquid from the input of the second pipe 52. The first separator 6 has a gas phase output end and a liquid phase output end. The gas phase output end of the first separator 6 discharges gas, and the liquid phase output end of the first separator 6 is connected to a storage tank 7. The liquid phase output end of the first separator 6 outputs liquid ammonia to the storage tank 7. The input end of the third pipe 53 is connected to the storage tank 7, and the storage tank 7 inputs liquid ammonia into the third pipe 53. The liquid ammonia is vaporized and discharged after absorbing heat in the third pipe 53.

[0024] The vent gas enters the first heat exchanger 5, where it exchanges heat with the low-temperature gas in the nitrogen circulation mechanism. Here, most of the gaseous ammonia is liquefied and then separated by the first separator 6. The liquid ammonia is sent back to the third pipe 53 to vaporize and absorb heat, reducing the refrigeration pressure on the nitrogen circulation mechanism and thus reducing energy consumption.

[0025] In some embodiments, the heat exchange separation mechanism 1 further includes a second heat exchanger 8, which has a fourth pipe 81, a fifth pipe 82, and a sixth pipe 83. The fourth pipe 81 is connected in series to the nitrogen pipe 3 and is located downstream of the cold end of the expander 2 and upstream of the first pipe 51. The input end of the fifth pipe 82 is connected to the gas phase output end of the first separator 6 to receive gas for further cooling and liquefaction. The output end of the fifth pipe 82 is connected to a second separator 9, which has a gas phase output end and a liquid phase output end. The liquid phase output end of the second separator 9 is connected to the storage tank 7, and the gas phase output end of the second separator 9 is connected to the input end of the sixth pipe 83. The output end of the sixth pipe 83 discharges the remaining gas, and the sixth pipe 83 uses the remaining gas as a supplementary cold source for the second heat exchanger 8. The second heat exchanger 8 receives the purge gas separated by the first separator 6, further liquefies the gaseous ammonia in it, and sends it to the second separator 9 for further separation. The gaseous gas separated by the second separator 9 can be discharged to the vent flare or sent to the tertiary or quaternary desulfurization system.

[0026] In some embodiments, the heat exchange separation mechanism 1 further includes a third heat exchanger 10, which has a seventh pipe 101 and an eighth pipe 102. The seventh pipe 101 is connected in series to the nitrogen pipe 3 and is located downstream of the first pipe 51. The input end of the eighth pipe 102 is connected to the output end of the third pipe 53. The liquid ammonia remaining in the eighth pipe 102 is vaporized and discharged after absorbing heat. The third heat exchanger 10 further vaporizes the liquid ammonia remaining after passing through the first heat exchanger 5. The vaporization of the liquid ammonia absorbs heat, further reducing the refrigeration pressure of the nitrogen circulation mechanism and reducing energy consumption.

[0027] In some embodiments, the third heat exchanger 10 further includes a ninth pipe 103 connected in series to the nitrogen pipe 3. The ninth pipe 103 is located upstream of the cold end of the expander 2 and downstream of the hot end of the expander 2. The ninth pipe 103 serves as a second heat source in the third heat exchanger 10 to cool the nitrogen gas coming from the hot end of the expander 2, thereby reducing the temperature of the nitrogen gas passing through the cold end of the expander 2 and decreasing the energy consumption of the expander 2.

[0028] In some embodiments, the nitrogen circulation mechanism further includes a branch pipe 11. The input end of the branch pipe 11 is connected to a nitrogen pipe 3 upstream of the cold end of the expander 2, and the output end of the branch pipe 11 is connected to a nitrogen pipe 3 at the hot end of the expander 2. The branch pipe 11 passes through the bearing of the expander 2, so that the nitrogen in the branch pipe 11 flows through the bearing of the expander 2. After the branch pipe 11 introduces nitrogen into the bearing of the expander 2 for use as lubricating gas, it is discharged into the hot end of the expander 2.

[0029] In some embodiments, a valve and a filter 12 are installed on the branch pipe 11, with the filter 12 located upstream of the expander 2 bearing. The filter 12 filters impurities in the branch pipe 11, preventing impurities from entering the expander 2 bearing.

[0030] In some embodiments, a venting pipe 13 is connected to the nitrogen pipeline 3, and a valve is installed on the venting pipe 13. The venting pipe 13 is used to discharge nitrogen when the pressure in the nitrogen pipeline 3 exceeds the limit, thereby reducing the pressure in the nitrogen pipeline 3.

[0031] The above description is intended to be illustrative and not restrictive. Those skilled in the art can make variations, modifications, substitutions, and alterations to the above embodiments within the scope of this disclosure. Moreover, the above examples (or one or more of them) can be used in combination with each other, and these embodiments can be combined with each other in various combinations or arrangements.

Claims

1. An ammonia recovery system for purge gas, characterized in that, The system includes a heat exchange separation mechanism (1), a nitrogen circulation mechanism, and an expander (2). The nitrogen circulation mechanism includes a nitrogen pipeline (3) and a compressor (4). The expander (2) has a hot end and a cold end. The nitrogen pipeline (3) passes through the hot end and the cold end of the expander (2). The nitrogen gas in the nitrogen pipeline (3) after being cooled by the cold end of the expander (2) passes through the heat exchange separation mechanism (1). The compressor (4) is installed on the nitrogen pipeline (3). The compressor (4) drives the nitrogen gas in the nitrogen pipeline (3) to flow sequentially through the cold end of the expander (2), the heat exchange separation mechanism (1), and the hot end of the expander (2) before returning to the compressor (4) to form a nitrogen circulation. The heat exchange separation mechanism (1) is connected to the purge gas. The heat exchange separation mechanism (1) uses the nitrogen output from the cold end of the expander (2) as a cold source to cool the purge gas, so that the ammonia in the purge gas is liquefied into liquid ammonia, thereby separating and outputting the liquefied liquid ammonia in the purge gas.

2. The ammonia recovery system for purge gas according to claim 1, characterized in that, The heat exchange separation mechanism (1) includes a first heat exchanger (5), which has a first pipe (51), a second pipe (52), and a third pipe (53). The first pipe (51) is connected in series to the nitrogen pipe (3) and is located downstream of the cold end of the expander (2). The input end of the second pipe (52) is connected to the purge gas, and the output end of the second pipe (52) is connected to a first separator (6). The first separator (6) separates the gas from the second pipe (52). The input material is separated into gas and liquid phases. The first separator (6) has a gas phase output end and a liquid phase output end. The gas phase output end of the first separator (6) discharges gas, and the liquid phase output end of the first separator (6) is connected to a storage tank (7). The liquid phase output end of the first separator (6) outputs liquid ammonia to the storage tank (7). The input end of the third pipe (53) is connected to the storage tank (7). The storage tank (7) inputs liquid ammonia to the third pipe (53). The liquid ammonia is vaporized and absorbs heat in the third pipe (53) before being discharged.

3. An ammonia recovery system for purge gas according to claim 2, characterized in that, The heat exchange separation mechanism (1) further includes a second heat exchanger (8), which has a fourth pipe (81), a fifth pipe (82), and a sixth pipe (83). The fourth pipe (81) is connected in series to the nitrogen pipe (3). The fourth pipe (81) is located downstream of the cold end of the expander (2) and upstream of the first pipe (51). The input end of the fifth pipe (82) is connected to the gas phase output end of the first separator (6) to receive gas into the fifth pipe. The fifth pipe (82) is further cooled and liquefied. The output end of the fifth pipe (82) is connected to the second separator (9). The second separator (9) has a gas phase output end and a liquid phase output end. The liquid phase output end of the second separator (9) is connected to the storage tank (7). The gas phase output end of the second separator (9) is connected to the input end of the sixth pipe (83). The output end of the sixth pipe (83) discharges the remaining gas. The sixth pipe (83) uses the remaining gas as a supplementary cold source for the second heat exchanger (8).

4. An ammonia recovery system for purge gas according to claim 2, characterized in that, The heat exchange separation mechanism (1) further includes a third heat exchanger (10), which has a seventh pipe (101) and an eighth pipe (102). The seventh pipe (101) is connected in series to the nitrogen pipe (3) and is located downstream of the first pipe (51). The input end of the eighth pipe (102) is connected to the output end of the third pipe (53). The residual liquid ammonia in the eighth pipe (102) is vaporized and discharged after absorbing heat.

5. An ammonia recovery system for purge gas according to claim 4, characterized in that, The third heat exchanger (10) also has a ninth pipe (103) connected in series to the nitrogen pipe (3), the ninth pipe (103) being located upstream of the cold end of the expander (2) and downstream of the hot end of the expander (2).

6. An ammonia recovery system for purge gas according to any one of claims 1 to 5, characterized in that, The nitrogen circulation mechanism also includes a branch pipe (11), the input end of which is connected to the nitrogen pipe (3) upstream of the cold end of the expander (2), and the output end of the branch pipe (11) is connected to the nitrogen pipe (3) at the hot end of the expander (2). The branch pipe (11) passes through the bearing of the expander (2) so that the nitrogen in the branch pipe (11) flows through the bearing of the expander (2).

7. An ammonia recovery system for purge gas according to claim 6, characterized in that, A valve and a filter (12) are installed on the branch pipeline (11), the filter (12) being located upstream of the bearing of the expander (2).

8. An ammonia recovery system for purge gas according to claim 1, characterized in that, The nitrogen pipeline (3) is connected to a venting pipeline (13), and a valve is installed on the venting pipeline (13).

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