Ammonia flare zero emission system and treatment process

Abstract

The application provides an ammonia flare zero emission system and a treatment process, which comprises an ammonia gas conveying main pipe, the ammonia gas conveying main pipe is communicated with each ammonia gas emission device, and further comprises an ammonia gas absorption tower, a liquid inlet of the ammonia gas absorption tower is communicated with a water inlet pipe, a gas inlet is communicated with the ammonia gas conveying main pipe, a spraying assembly for spraying rising ammonia gas is arranged in the top of the ammonia gas absorption tower; a circulating pump inlet is communicated with the bottom of the ammonia gas absorption tower through a pipeline, an outlet pipeline is communicated with the middle part of the ammonia gas absorption tower, the pipeline connected with the circulating pump outlet is further communicated with an ammonia evaporation device, and a valve is arranged on an output main pipe; a propylene cooler is arranged on the pipeline connected with the circulating pump outlet, and the treatment process of the ammonia flare zero emission system is further provided. The ammonia gas emitted by the ammonia flare is treated by using the low-temperature deep absorption, continuous concentration and recovery and upgrading coupling technology, the ammonia gas in the ammonia flare gas is absorbed and concentrated before being combusted by the flare, the concentrated ammonia gas is sent back to the ammonia evaporation device for treatment, and high-quality ammonia water is obtained.

Description

Technical Field

[0001] This invention relates to the field of coal chemical technology, specifically to an ammonia flare zero-emission system and treatment process. Background Technology

[0002] Ammonia flare systems are used to treat ammonia emitted from liquid ammonia tanks, other ammonia emission equipment, and ammonia stripping units in chemical plants. Gaseous ammonia burns at the top of the flare, causing significant environmental impact. This technology not only allows for the recovery of ammonia gas to produce ammonia water but also ensures that the flare system's emission outlets meet emission standards, thus reducing the direct environmental impact of ammonia emissions.

[0003] However, through analysis of the use of ammonia flares in existing 1.8 million tons / year and 700,000 tons / year plants, as well as the use of ammonia flares in similar industries, the following problems were found in ammonia flare combustion:

[0004] Under extreme weather conditions, ammonia flares are prone to extinguishing or are difficult to ignite due to their low resistance to strong winds. During normal production, ammonia flares are easily extinguished when wind speeds exceed level 5, extinguishing 1-2 times per month. When wind speeds exceed level 17, the ammonia flare is almost impossible to ignite. However, after the flare extinguishes, the released air, without combustion, can cause serious environmental pollution accidents. Furthermore, when the ammonia unit or tank experiences overpressure, the rapid full opening of the vent valve or the activation of the safety valve will allow a large amount of liquid ammonia to enter the ammonia flare system, resulting in a significant ammonia release and incomplete combustion at the flare tip. Moreover, if the original ammonia flare system design lacks effective backfire prevention devices, significant fluctuations in vent air flow during normal production, especially during intermittent venting, can easily cause backfire of the flare combustion gas, leading to secondary accidents.

[0005] In summary, the industry has tried to address the above problems and prevent secondary accidents by increasing fuel gas flow, multiple ignitions, modifying the flare head for wind protection, reducing nitrogen usage in the ammonia flare main, ensuring a reduction in the total gas volume entering the flare head, and continuously replenishing nitrogen in the ammonia flare main. However, these measures have not been effective enough, and the problems caused by ammonia combustion in the system have not been completely resolved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a zero-emission ammonia flare system. This system employs a coupled technology of low-temperature deep absorption, continuous concentration, and recovery and quality improvement to absorb ammonia gas emitted from the flare before combustion. The absorbed ammonia is then returned to the ammonia stripping unit for further treatment, yielding high-quality ammonia water for use in desulfurization and denitrification units, replacing liquid ammonia. Through this technology, the ammonia flare achieves zero ammonia emissions, while the recovered ammonia water reduces operating costs by replacing liquid ammonia, achieving both environmental benefits and lowering the operating costs of the enterprise's ammonia flare.

[0007] To solve the above-mentioned technical problems, the first inventive solution provided by the present invention is: an ammonia flare zero-emission system, including an ammonia gas delivery main pipe, wherein the ammonia gas delivery main pipe is connected to each ammonia gas emission device for collecting the ammonia gas released by each ammonia gas emission device, and further comprising:

[0008] The ammonia absorption tower has a liquid inlet connected to a water inlet pipe and a gas inlet connected to a main ammonia delivery pipe. A spray assembly is installed inside the top of the ammonia absorption tower to spray ammonia gas rising to the top of the tower. The spray assembly is connected to a spray liquid delivery pipe.

[0009] The circulating pump has its inlet connected to the bottom of the ammonia absorption tower via a pipeline, and its outlet connected to the middle of the ammonia absorption tower. It is used to drive the circulation of low-concentration ammonia water so that the ammonia gas sent into the ammonia absorption tower can fully contact and be absorbed by the water. The pipeline connected to the outlet of the circulating pump is also connected to the ammonia stripping device via an output main pipe, and a valve is provided on the output main pipe.

[0010] The propylene cooler is located on the pipeline connected to the outlet of the circulating pump. It is used to reduce the temperature of low-concentration ammonia water in the ammonia absorption tower through multiple heat exchanges.

[0011] Preferably, the spray assembly includes a first spray assembly and a second spray assembly. Both the first spray assembly and the second spray assembly are used to spray and wash the ammonia gas rising to the top of the tower. The first spray assembly is connected to the pipeline connected to the outlet of the propylene cooler, and the second spray assembly is connected to the low-temperature demineralized water conveying pipe. The second spray assembly is located above the liquid outlet of the inlet pipe.

[0012] Preferably, the ammonia absorption tower is equipped with a densitometer and a liquid level indicator and regulator at the bottom, and the valves on the output main pipe are electrically controlled valves, all of which are electrically connected to the liquid level indicator and regulator and the densitometer.

[0013] Preferably, the top of the ammonia absorption tower is connected to an exhaust pipe, which is connected to a nitrogen compression drying system. The outlet of the nitrogen compression drying system is connected to an ammonia stripping device via a pipeline. The outlet of the nitrogen compression drying system is connected to an ammonia flare via a flare delivery pipe, which is used to send the safety protection gas in the pipeline to the flare.

[0014] Preferably, the ammonia gas transmission main pipe is equipped with a first flow meter and valve A, and the ammonia gas transmission main pipe is also equipped with a first ammonia gas transmission branch pipe, which is connected to the flare transmission pipe;

[0015] A B valve is provided on the first ammonia delivery branch pipe. The A valve is located on the main ammonia delivery pipe between the first ammonia delivery branch pipe and the first flow meter. The first flow meter and the B valve are connected through the second ammonia delivery branch pipe. The A valve is connected to the second ammonia delivery branch pipe through a pipeline. The A valve, the B valve, and the first flow meter are all electrically connected to the controller. The A valve, the B valve, and the first flow meter are all electrically connected to the power supply.

[0016] Preferably, the nitrogen gas pipeline connected to the liquid ammonia spherical tank is also connected to the flare delivery pipeline.

[0017] Preferably, the flare delivery pipe is equipped with a second flow meter and a flame arrester.

[0018] The second inventive solution provided by this invention: a treatment process for an ammonia flare zero-emission system, comprising the following steps:

[0019] When the ammonia flow rate is ≤3000m 3 At a rate of / h, the ammonia gas collected in the ammonia gas delivery main is sent into the ammonia absorption tower. 95% of the ammonia gas is absorbed by water sprayed inside the tower at low temperatures, forming an ammonia solution. The remaining 5% of ammonia gas, not absorbed by the water, rises within the absorption tower and undergoes secondary absorption by a low-temperature desalination solution and low-concentration ammonia solution, reducing the ammonia gas concentration at the top of the tower to 0 ppm. When the density at the bottom of the absorption tower reaches 0.960 or the liquid level exceeds the set value, the ammonia solution is sent to the ammonia stripping unit to produce ammonia water. When the temperature inside the ammonia absorption tower is too high, the water vapor flowing from the top of the tower is condensed in the nitrogen compression drying system, and the condensed gas is sent to the ammonia stripping unit.

[0020] When the ammonia flow rate fed into the ammonia absorption tower is ≥3000 m³ / h 3 / h, some of the ammonia in the main ammonia delivery pipe will also be sent into the first ammonia delivery branch pipe, and then sent to the ammonia flare for combustion through the first ammonia delivery branch pipe.

[0021] Preferably, the temperature of the low-temperature demineralized water is -2℃ to 5℃.

[0022] Preferably, the water sprayed inside the ammonia absorption tower absorbs 95% of the ammonia at a temperature of -2℃ to 5℃.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. This invention does not require increasing the fuel gas flow rate, multiple ignitions, windproof modifications to the flare head, or reducing the amount of nitrogen used in the ammonia flare main pipe to ensure a reduction in the total gas volume entering the flare head and avoid secondary accidents.

[0025] 2. This invention involves sending the ammonia gas from the liquid ammonia spherical tanks processed by the ammonia flare system, the ammonia gas emitted from various ammonia emission devices, and the ammonia gas from the ammonia stripping device into an ammonia absorption tower via an ammonia gas delivery main. The ammonia gas undergoes cryogenic absorption in low-temperature water. Because cryogenic water increases the absorption capacity of ammonia gas, a spray assembly is installed inside the ammonia absorption tower to further reduce the probability of ammonia gas emission. This spray assembly further absorbs any ammonia gas rising within the absorption tower that has not yet been absorbed by the cryogenic water. In contrast, the ammonia flare emission system is burned by the flare (e.g.,...). Figure 1 As shown, this invention involves feeding ammonia gas into an ammonia absorption tower for absorption in a low-temperature environment. A circulating pump continuously returns the low-concentration ammonia solution from the bottom of the tower to the center. This not only ensures uniform ammonia concentration within the tower but also increases the probability of the low-concentration ammonia solution absorbing ammonia gas. When the concentration reaches a set value, the ammonia solution is sent to an ammonia stripping device for reuse. This achieves zero ammonia emissions from the ammonia flare.

[0026] 3. The ammonia flare zero-emission system provided in this invention prevents ammonia gas from being emitted into the ammonia flare, thus completely solving the ammonia flare blockage problem. Furthermore, all ammonia gas that would otherwise be emitted into the flare is recovered, increasing ammonia water production. Moreover, the integrated utilization of toxic and harmful ammonia gases not only solves environmental problems but also extends the lifespan of the ammonia flare. Simultaneously, the ammonia gas that would otherwise be emitted undergoes low-cost, high-efficiency cleaning treatment, turning ammonia waste into a valuable resource and maximizing economic benefits. Attached Figure Description

[0027] Figure 1 A process flow diagram of an ammonia flare system based on existing technology is provided.

[0028] Figure 2 This invention provides a process flow diagram of an ammonia flare zero-emission system.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Liquid ammonia spherical tank; 2. Ammonia emission equipment; 3. Ammonia main pipeline; 4. Ammonia absorption tower; 5. Low-temperature demineralized water spray assembly; 6. Circulating pump; 7. Propylene cooler; 8. Ammonia stripping device; 9. Nitrogen compression drying system; 10. Ammonia flare; 11. Densitometer; 12. Water spray assembly; 13. First flow meter; 14. First ammonia delivery branch pipeline; 15. Flame arrester; 16. Second flow meter. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] The inventors discovered the following problems with ammonia torch combustion:

[0033] 1. In extreme weather conditions, ammonia flares are easily extinguished or difficult to ignite because they have low resistance to strong winds. During normal production, ammonia flares are prone to extinguishing when the wind force is greater than level 5, extinguishing 1-2 times per month. When the wind force exceeds level 17, ammonia flares are almost impossible to ignite. However, after the ammonia flare is extinguished, the released air will be directly discharged without combustion, causing serious environmental pollution accidents.

[0034] 2. When an overpressure occurs in the ammonia tank of the ammonia unit, the vent valve will be opened fully or the safety valve will be activated, resulting in a large amount of liquid ammonia entering the ammonia flare system. This will cause a large amount of ammonia to be discharged from the ammonia flare system, leading to incomplete combustion at the flare head.

[0035] 3. In the original ammonia flare system design, no effective backfire prevention device was installed. When there are large fluctuations in the flow rate of the venting air during normal production, especially during the intermittent discharge of venting air, it is very easy to cause backfire of the flare combustion gas, which can lead to secondary accidents.

[0036] Therefore, to address the aforementioned problems, this invention provides a zero-emission system and process for ammonia flares. This system employs a coupled technology of low-temperature deep absorption, continuous concentration, and recovery and upgrading to absorb and concentrate the ammonia gas emitted from the flare before combustion. The concentrated ammonia is then returned to the ammonia stripping unit for further treatment, yielding high-quality ammonia water for use in desulfurization and denitrification units, replacing liquid ammonia. Through this technology, the ammonia flare achieves zero ammonia emissions, while the recovered ammonia water reduces operating costs by replacing liquid ammonia, achieving both environmental benefits and lowering the operating costs of the enterprise's ammonia flare.

[0037] The following is for reference. Figure 2 A zero-emission ammonia flare system and process according to an embodiment of the present invention are described.

[0038] refer to Figure 2 A zero-emission ammonia flare system includes an ammonia gas transmission main pipe 3, which is connected to various ammonia gas emission devices for collecting the ammonia gas released by each device. Each ammonia gas emission device includes a liquid ammonia spherical tank 1, other ammonia gas emission devices 2, and an ammonia stripping device 8. The liquid ammonia spherical tank 1, other ammonia gas emission devices 2, and ammonia stripping device 8 are all connected to the inlet of the ammonia gas transmission main pipe 3. The system also includes an ammonia absorption tower 4, a circulating pump 6, and a propylene cooler 7. The liquid inlet of the ammonia absorption tower 4 is connected to a water inlet pipe 5, and the gas inlet of the ammonia absorption tower 4 is connected to the ammonia gas transmission main pipe 3. A spray assembly is installed inside the top of the ammonia absorption tower 4 to spray the ammonia gas rising to the top of the tower. The spray assembly is connected to a spray liquid transmission pipe.

[0039] The inlet of the circulating pump 6 is connected to the bottom of the ammonia absorption tower 4 via a pipeline, and the outlet pipeline of the circulating pump 6 is connected to the middle of the ammonia absorption tower 4. The circulating pump 6 is used to drive the circulation of low-concentration ammonia water so that the ammonia gas sent into the ammonia absorption tower 4 can fully contact and be absorbed by the water. The pipeline connected to the outlet of the circulating pump 6 is also connected to the ammonia stripping device 8 via the output main pipe, and a valve is provided on the output main pipe.

[0040] The propylene cooler 7 is located on the pipeline connected to the outlet of the circulating pump 6, and is used to reduce the temperature of the low-concentration ammonia water in the ammonia absorption tower 4 through multiple heat exchanges via the propylene cooler 7.

[0041] Specifically, the spray assembly includes a first spray assembly and a second spray assembly 12. Both the first spray assembly and the second spray assembly 12 are used to spray and wash the ammonia gas rising to the top of the tower. The first spray assembly is connected to the pipeline connected to the outlet of the propylene cooler 7. The second spray assembly 12 is connected to the low-temperature demineralized water conveying pipe and is located above the liquid outlet of the water inlet pipe 5.

[0042] The purpose of this setup is to allow for secondary absorption of ammonia gas that has not been absorbed by water as it rises in the ammonia absorption tower. The second spray assembly 12 sprays low-temperature demineralized water to ensure the quality of the ammonia water prepared by the ammonia stripping unit.

[0043] Specifically, the bottom of the ammonia absorption tower 4 is equipped with a densitometer 11 and a level indicator and regulator. The valves on the output main pipe are electrically controlled valves, which are electrically connected to the level indicator and regulator and the densitometer 11. When the density detected at the bottom of the ammonia absorption tower 4 reaches 0.960 or the liquid level is higher than the set value, the ammonia solution is transported to the ammonia stripping unit 8 to produce ammonia water.

[0044] Specifically, the top of the ammonia absorption tower 4 is connected to an exhaust pipe, which is connected to the nitrogen compression and drying system 9. The outlet of the nitrogen compression and drying system 9 is connected to the ammonia stripping device 8 through a pipeline. The outlet of the nitrogen compression and drying system 9 is connected to the ammonia flare 10 through a flare delivery pipe, which is used to send the safety protection gas in the pipeline to the flare.

[0045] Specifically, the ammonia gas transmission main pipe 3 is also equipped with a first flow meter 13 and a valve A, and the ammonia gas transmission main pipe 3 is also equipped with a first ammonia gas transmission branch pipe 14, which is connected to the flare transmission pipe.

[0046] A B valve is provided on the first ammonia gas delivery branch pipe 14. The A valve is located on the ammonia gas delivery main pipe 3 between the first ammonia gas delivery branch pipe 14 and the first flow meter 13. The first flow meter 13 and the B valve are connected through the second ammonia gas delivery branch pipe. The A valve is connected to the second ammonia gas delivery branch pipe through a pipeline. The A valve, the B valve, and the first flow meter 13 are all electrically connected to the controller. The A valve, the B valve, and the first flow meter 13 are all electrically connected to the power supply.

[0047] Specifically, the nitrogen gas pipeline connected to the liquid ammonia spherical tank 1 is also connected to the flare delivery pipeline.

[0048] Specifically, the flare delivery pipe is equipped with a second flow meter 16 and a flame arrester 15. The flame arrester 15 is provided to prevent the flare from backfired.

[0049] A process for a zero-emission ammonia flare system includes the following steps:

[0050] When the ammonia flow rate is ≤3000m 3 At a rate of / h, ammonia gas discharged normally or in an accident from the liquid ammonia spherical tank 1, ammonia emission equipment 2, and ammonia stripping device 8 is sent into the ammonia absorption tower 4. 95% of the ammonia gas is absorbed at low temperature by water sprayed inside the ammonia absorption tower 4, forming an ammonia solution. The remaining 5% of ammonia gas, not absorbed by the water, rises within the ammonia absorption tower 4 and undergoes secondary absorption by a low-temperature desalination solution and water, reducing the ammonia gas concentration at the top of the ammonia absorption tower 4 to 0 ppm. When the density at the bottom of the ammonia absorption tower 4 reaches 0.960 or the liquid level exceeds the set value, the ammonia solution is sent to the ammonia stripping device 8 to produce ammonia water. When the temperature inside the ammonia absorption tower 4 is too high, the water vapor flowing from the top of the ammonia absorption tower 4 is condensed in the nitrogen compression drying system 9, and the condensed gas is sent to the ammonia stripping device 8.

[0051] When the ammonia flow rate fed into ammonia absorption tower 4 is ≥3000 m³ / h 3 / h, some of the ammonia in the main ammonia delivery pipe 3 will also be sent into the first ammonia delivery branch pipe 14, and then sent to the ammonia flare for combustion via the first ammonia delivery branch pipe 14.

[0052] Specifically, the temperature of the low-temperature desalinated water is -2℃ to 5℃.

[0053] Specifically, the water sprayed inside the ammonia absorption tower 4 absorbs 95% of the ammonia at a temperature of -2℃ to 5℃.

[0054] Working principle:

[0055] like Figure 1 As shown, in the prior art, there is an ammonia flare system in which the liquid ammonia collection tank 1, other ammonia emission equipment 2, and ammonia stripping device 8 are all connected to an ammonia gas delivery main pipe 3, and the ammonia gas in the ammonia gas delivery main pipe 3 is directly sent into the ammonia flare for combustion.

[0056] Ammonia flares are prone to extinguishing or failing to ignite under extreme weather conditions due to their low resistance to strong winds. During normal production, flares easily extinguish when wind speeds exceed level 5, extinguishing 1-2 times per month. When wind speeds exceed level 17, the flare is almost impossible to ignite. However, after the flare extinguishes, the released air, without combustion, can cause serious environmental pollution. Furthermore, when overpressure occurs in the ammonia unit or tank, the rapid full opening of the vent valve or the activation of the safety valve will allow a large amount of liquid ammonia to enter the flare system, resulting in significant ammonia emissions and incomplete combustion at the flare tip. Moreover, if the original ammonia flare system design lacks effective backfire prevention devices, significant fluctuations in vent air flow during normal production, especially during intermittent venting, can easily cause backfire of the flare combustion gas, leading to secondary accidents.

[0057] Therefore, to avoid the aforementioned problems and simultaneously achieve environmental benefits while reducing the operating costs of ammonia flares, this invention proposes a technical modification to existing ammonia flare systems.

[0058] like Figure 2 As shown, ammonia gas discharged normally or in an accident from the liquid ammonia spherical tank 1, ammonia emission equipment 2, and ammonia stripping device 8 is sent to the ammonia absorption tower 4 via the ammonia gas transmission main pipe 3. 95% of the ammonia gas is absorbed by the water sprayed inside the ammonia absorption tower 4 at low temperature, forming an ammonia solution. The remaining 5% of ammonia gas, not absorbed by the water, rises within the ammonia absorption tower 4 and undergoes secondary absorption by the low-temperature desalination solution and water. The ammonia gas at the top of the ammonia absorption tower 4 drops to 0 ppm. When the density at the bottom of the ammonia absorption tower 4 reaches 0.960 or the liquid level is higher than the set value, the control valve is opened, and the ammonia solution is sent to the ammonia stripping device 8 via the output main pipe to produce ammonia water. When the temperature inside the ammonia absorption tower 4 is too high, the water vapor flowing out from the top of the ammonia absorption tower 4 is condensed in the nitrogen compression drying system 9, and the condensed gas is sent to the ammonia stripping device 8.

[0059] When the liquid ammonia spherical tank 1, ammonia emission equipment 2 and ammonia stripping device 8 are not emitting ammonia normally, some of the ammonia in the ammonia transmission main pipe 3 will be sent into the first ammonia transmission branch pipe 14, and then sent to the ammonia flare for combustion through the first ammonia transmission branch pipe 14.

[0060] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A zero-emission ammonia flare system, comprising an ammonia gas delivery main pipe (3), wherein the ammonia gas delivery main pipe (3) is connected to various ammonia gas emission devices for collecting ammonia gas released by each ammonia gas emission device, characterized in that, The ammonia gas main pipe (3) is equipped with a first flow meter (13) and a valve A. The ammonia gas main pipe (3) is also equipped with a first ammonia gas delivery branch pipe (14), which is connected to the flare delivery pipe. A B valve is provided on the first ammonia gas delivery branch pipe (14). The valve A is located on the ammonia gas delivery main pipe (3) between the first ammonia gas delivery branch pipe (14) and the first flow meter (13). The first flow meter (13) and the B valve are connected through the second ammonia gas delivery branch pipe. The valve A is connected to the second ammonia gas delivery branch pipe through a pipeline. The valve A, the B valve, and the first flow meter (13) are all electrically connected to the controller. The valve A, the B valve, and the first flow meter (13) are all electrically connected to the power supply. The system also includes: The ammonia absorption tower (4) has a liquid inlet connected to the water inlet pipe (5) and a gas inlet connected to the ammonia transmission main pipe (3). The top of the ammonia absorption tower (4) is equipped with a spray assembly. The spray assembly sprays the ammonia gas that rises to the top of the ammonia absorption tower (4). The spray assembly is connected to the spray liquid transmission pipe. The spray assembly includes a first spray assembly and a second spray assembly (12). Both the first spray assembly and the second spray assembly (12) are used to spray and wash the ammonia gas that rises to the top of the tower. The first spray assembly is connected to the pipeline connected to the outlet of the propylene cooler (7). The second spray assembly (12) is connected to the low-temperature demineralized water transmission pipe. The second spray assembly (12) is located above the liquid outlet of the water inlet pipe (5). The circulation pump (6) has its inlet connected to the bottom of the ammonia absorption tower (4) via a pipeline, and its outlet connected to the middle of the ammonia absorption tower (4). It is used to drive the circulation of low-concentration ammonia water through the circulation pump (6) so that the ammonia gas sent into the ammonia absorption tower (4) can fully contact and absorb with the water. The pipeline connected to the outlet of the circulation pump (6) is also connected to the ammonia stripping device (8) through the output main pipe. The output main pipe is equipped with a valve. The bottom of the ammonia absorption tower (4) is equipped with a density meter (11) and a liquid level indicator and regulator. The valve on the output main pipe is an electrically controlled valve. The electrically controlled valve is electrically connected to the liquid level indicator and the density meter (11). A propylene cooler (7) is installed on the pipeline connected to the outlet of the circulating pump (6) to reduce the temperature of low-concentration ammonia water in the ammonia absorption tower (4) through multiple heat exchanges. When the density monitored at the bottom of the ammonia absorption tower (4) reaches 0.960 or the liquid level is higher than the set value, the control valve is opened and the ammonia water solution is transported to the ammonia stripping device through the output main pipe to produce ammonia water. The top of the ammonia absorption tower (4) is connected to an exhaust pipe, which is connected to the nitrogen compression drying system (9). The outlet of the nitrogen compression drying system (9) is connected to the ammonia stripping device (8) through a pipeline. The outlet of the nitrogen compression drying system (9) is connected to the ammonia flare (10) through the flare delivery pipe to send the safety protection gas in the pipeline to the flare.

2. The ammonia flare zero-emission system according to claim 1, characterized in that, Each ammonia emission device includes a liquid ammonia spherical tank (1), and the nitrogen gas transmission pipeline connected to the liquid ammonia spherical tank (1) is connected to the flare delivery pipe.

3. The ammonia flare zero-emission system according to claim 1, characterized in that, The flare delivery pipe is equipped with a second flow meter (16) and a flame arrester (15).

4. The treatment process of an ammonia flare zero-emission system as described in any one of claims 1 to 3, characterized in that, Includes the following steps: When ammonia flow rate < 3000 m³ 3 At a rate of / h, the ammonia gas collected by the ammonia gas delivery main pipe (3) is sent into the ammonia gas absorption tower (4). The water sprayed in the ammonia gas absorption tower (4) absorbs 95% of the ammonia gas at low temperature to form an ammonia water solution. The remaining 5% of the ammonia gas that is not absorbed by the water rises in the ammonia gas absorption tower (4) and is absorbed a second time by the low temperature desalination water solution and the low concentration ammonia water to reduce the ammonia gas at the top of the ammonia gas absorption tower (4) to 0ppm. When the density detected at the bottom of the ammonia gas absorption tower (4) reaches 0.960 or the liquid level is higher than the set value, the ammonia water solution is sent to the ammonia stripping device (8) to produce ammonia water. When the temperature in the ammonia gas absorption tower (4) is too high, the water vapor flowing out from the top of the ammonia gas absorption tower (4) will be condensed in the nitrogen compression drying system (9), and the condensed gas is sent to the ammonia stripping device (8). When the ammonia flow rate fed into the ammonia absorption tower (4) is ≥3000 m³ / h 3 / h, some of the ammonia in the main ammonia delivery pipe (3) will also be sent into the first ammonia delivery branch pipe (14), and then sent to the ammonia torch for combustion via the first ammonia delivery branch pipe (14).

5. The treatment process of an ammonia flare zero-emission system according to claim 4, characterized in that, The temperature of the low-temperature desalinated water is -2℃ to 5℃.

6. The treatment process of an ammonia flare zero-emission system according to claim 4, characterized in that, The water sprayed inside the ammonia absorption tower (4) absorbs 95% of the ammonia at a temperature of -2℃ to 5℃.

Images