Nitrogen outlet back flushing device of nitrogen generator

Abstract

The application discloses a nitrogen outlet back flushing device of a nitrogen generator, and belongs to the technical field of nitrogen production. The device comprises two nitrogen main pipes arranged at the outlets of nitrogen adsorption towers, first three-way pipes fixedly installed at the ends of the two nitrogen main pipes, a back flushing mechanism arranged between the two first three-way pipes, nitrogen branch pipes fixedly installed at the other ends of the two first three-way pipes, second three-way pipes fixedly installed at the ends of the two nitrogen branch pipes, first exhaust branch pipes fixedly installed at the opposite ends of the two second three-way pipes, first gas path one-way valves installed on the two first exhaust branch pipes, and the two first gas path one-way valves are oppositely distributed. The device can realize that two groups of nitrogen adsorption towers share the same group of back flushing mechanisms, and alternately perform adsorption and regeneration, complete oxygen-nitrogen separation, and more effectively utilize nitrogen in the pipeline, so that the nitrogen production purity is ensured.

Description

Technical Field

[0001] This application relates to the field of nitrogen manufacturing technology, and more specifically, to a nitrogen outlet backflushing device for a nitrogen generator. Background Technology

[0002] The nitrogen generator's adsorption tower is located in the oxygen-nitrogen separation unit, which is the core unit of the nitrogen generator. It mainly consists of an adsorption tower containing a specialized adsorbent, pneumatic valves, a pressing cylinder, and a silencer. Based on the difference in the amount of oxygen adsorbed by the adsorbent in compressed air under different pressures, the adsorption tower pressurizes to absorb oxygen and produce nitrogen, while depressurizing to deoxygenate and regenerate the adsorbent. The two towers work alternately to achieve continuous nitrogen production. The backflushing device is mainly used in air separation equipment. In existing technology, the equipment operates by switching between adsorption towers. During one adsorption cycle, the gas in the other adsorption tower is completely discharged. When switching adsorption towers, some nitrogen is directly lost, resulting in insufficient nitrogen utilization and a significant impact on purity.

[0003] The invention patent with authorization announcement number CN210764336U discloses a nitrogen outlet backflushing device for a nitrogen generator, including a nitrogen pipe disposed between two sets of nitrogen adsorption towers. The two ends of the nitrogen pipe are connected to the two sets of nitrogen adsorption towers respectively through a nitrogen outlet and a nitrogen inlet. A shut-off valve B is provided at the middle position of the nitrogen pipe. A backflushing pipe is also provided on the nitrogen pipe. A shut-off valve A and a one-way valve are sequentially provided on the backflushing pipe. The nitrogen pipe and the backflushing pipe are made of low-carbon stainless steel pipes, and the inner wall of the steel pipes is electrolytically polished. The nitrogen pipe and the backflushing pipe are both integrally formed steel structures. The one-way valve is a straight-through one-way valve, which is connected to the backflushing pipe by a thread. The shut-off valves A and B are right-angle pneumatic shut-off valves. This technical solution operates through exchange. During one adsorption cycle, the gas in another adsorption tower is completely discharged. When switching adsorption towers, a portion of the nitrogen enters the adsorption tower through a backflushing device, allowing the nitrogen to be reused and causing the pressure inside the adsorption tower to rise rapidly, thereby ensuring the purity of the nitrogen.

[0004] However, the above technical solution still has some shortcomings. For example, when the two sets of nitrogen adsorption towers work alternately, two sets of backflush pipes need to be set up independently to achieve backflush control. The residual nitrogen in the backflush pipes is difficult to be fully utilized, which may affect the purity of subsequent nitrogen production. Summary of the Invention

[0005] To address the aforementioned problems, this application provides a nitrogen outlet backflushing device for a nitrogen generator, employing the following technical solution:

[0006] A nitrogen generator nitrogen outlet backflushing device includes two main nitrogen pipes located at the outlet of a nitrogen adsorption tower. Each of the two main nitrogen pipes has a first tee pipe fixedly installed at its end. A backflushing mechanism is provided between the two first tee pipes. Each of the other ends of the two first tee pipes has a nitrogen branch pipe fixedly installed. Each of the two nitrogen branch pipes has a second tee pipe fixedly installed at its end. Each of the two second tee pipes has a first exhaust branch pipe fixedly installed at its opposite end. Each of the two first exhaust branch pipes has a first one-way valve installed on it, and the two first one-way valves are opposite to each other. Each of the two first exhaust branch pipes has a third tee pipe fixedly installed at its opposite end. A connecting pipe is fixedly installed at the other end of the third tee pipe. Each of the two second tee pipes has a second exhaust branch pipe fixedly installed at its other end. Each of the two second exhaust branch pipes has a first shut-off valve fixedly installed on it. Each of the two second exhaust branch pipes has a four-way pipe fixedly installed at its opposite end. One end of the connecting pipe is fixedly connected to the four-way pipe, and the other end of the four-way pipe has an exhaust pipe fixedly installed.

[0007] By adopting the above technical solution, clean air feedstock first enters one of the nitrogen adsorption towers, where O, CO, and H₂O are adsorbed by the adsorbent. When the adsorbent in the nitrogen adsorption tower is saturated with oxygen, the inlet valve of the nitrogen adsorption tower is closed, and the inlet valve of the other nitrogen adsorption tower is opened. At the same time, the first gas path check valve and the first shut-off valve on the corresponding side of the original nitrogen adsorption tower are opened to depressurize the adsorption tower. Nitrogen is output from the first exhaust branch pipe, the second exhaust branch pipe, and the exhaust pipe on the corresponding side. In conjunction with the activation of the backflushing mechanism, a small portion of nitrogen flows back into the original nitrogen adsorption tower to desorb the adsorbed O, CO, and H₂O, thereby achieving deoxygenation and regeneration of the adsorbent. The two sets of nitrogen adsorption towers share the same backflushing mechanism, alternating between adsorption and regeneration to complete oxygen-nitrogen separation. This allows for more effective utilization of the nitrogen in the pipeline, ensuring the purity of the nitrogen produced.

[0008] Furthermore, the backflush mechanism includes two backflush pipes respectively fixedly installed on the first three-way pipe, each of the two backflush pipes is fixedly installed with a second shut-off valve, and the opposite ends of the two backflush pipes are jointly fixedly installed with a first loop pipe, on which two spaced second air passage one-way valves are fixedly installed.

[0009] By adopting the above technical solution, the second gas path check valve and the corresponding second shut-off valve are opened, allowing nitrogen to flow into the first loop pipe through the backflush pipe. When the first loop pipe is filled with nitrogen, the corresponding second shut-off valve is closed. When the nitrogen in the nitrogen main pipe, nitrogen branch pipe, first exhaust branch pipe, and second exhaust branch pipe is about to be completely discharged, the corresponding first shut-off valve is closed and the corresponding second shut-off valve is opened, allowing the nitrogen in the first loop pipe to flow out. Part of the nitrogen flows out through the backflush pipe, nitrogen branch pipe, first exhaust branch pipe, and the first gas path check valve, while part of the nitrogen flows back into the nitrogen adsorption tower through the backflush pipe and nitrogen main pipe, desorbing the adsorbed O, CO, and H2O, thus achieving adsorbent deoxygenation and regeneration.

[0010] Furthermore, the two second air circuit check valves are oriented in the same direction along the first loop pipe, and the two second air circuit check valves are located on both sides of the connection line between the two backflush pipes.

[0011] By adopting the above technical solution, nitrogen gas in the first loop pipe can circulate in one direction.

[0012] Furthermore, the first loop pipe is a low-carbon stainless steel pipe, and the inner wall of the stainless steel pipe is electrolytically polished.

[0013] By adopting the above technical solutions, the low-carbon stainless steel pipe ensures the strength of the pipeline, and the electrolytic polishing makes the inner wall of the pipe smoother and brighter, which is conducive to the flow of nitrogen.

[0014] Furthermore, the backflush mechanism includes two backflush pipes respectively fixedly installed on the first three-way pipe, each of the two backflush pipes is fixedly installed with a second shut-off valve, each of the two backflush pipes has a second loop pipe fixedly installed at one end opposite to the other, a connecting pipe is fixedly installed between the two second loop pipes, and each of the two second loop pipes has two spaced second air passage one-way valves fixedly installed.

[0015] By adopting the above technical solution, the second gas path check valve and the corresponding second shut-off valve are opened, allowing nitrogen to flow into the second loop pipe through the backflush pipe. The two second loop pipes are connected by a connecting pipe to achieve interactive flow of nitrogen. When the two second loop pipes are filled with nitrogen, the corresponding second shut-off valve is closed. When the nitrogen in the nitrogen main pipe, nitrogen branch pipe, first exhaust branch pipe, and second exhaust branch pipe is about to be completely discharged, the corresponding first shut-off valve is closed and the corresponding second shut-off valve is opened, allowing the nitrogen in the two second loop pipes to flow out. Part of the nitrogen flows out through the backflush pipe, nitrogen branch pipe, first exhaust branch pipe, and first gas path check valve, while part of the nitrogen flows back into the nitrogen adsorption tower through the backflush pipe and nitrogen main pipe, desorbing the adsorbed O, CO, and H2O, thus achieving adsorbent deoxygenation and regeneration.

[0016] Furthermore, the two second air circuit check valves located on the same second loop pipe have the same orientation along the second loop pipe, and the two second air circuit check valves located on the same second loop pipe are respectively located on both sides of the connecting pipe.

[0017] By adopting the above technical solution, nitrogen in a single second loop pipe can circulate in one direction, and nitrogen in two second loop pipes can circulate interactively through a connecting pipe.

[0018] Furthermore, both the second loop pipe and the connecting pipe are made of low-carbon stainless steel, and the inner wall of the stainless steel pipe is electrolytically polished.

[0019] By adopting the above technical solutions, the low-carbon stainless steel pipe ensures the strength of the pipeline, and the electrolytic polishing makes the inner wall of the pipe smoother and brighter, which is conducive to the flow of nitrogen.

[0020] Furthermore, the nitrogen main pipe, nitrogen branch pipe, and backflush pipe are all made of low-carbon stainless steel, and the inner wall of the stainless steel pipe is electrolytically polished.

[0021] By adopting the above technical solutions, the low-carbon stainless steel pipe ensures the strength of the pipeline, and the electrolytic polishing makes the inner wall of the pipe smoother and brighter, which is conducive to the flow of nitrogen.

[0022] Furthermore, each of the first air circuit check valve, the first shut-off valve, the second shut-off valve, and the second air circuit check valve is equipped with an electronic control unit, and each electronic control unit is controlled globally through a PLC controller.

[0023] By adopting the above technical solution and using a PLC controller, more efficient and timely coordinated control of each valve body can be achieved.

[0024] Furthermore, the first exhaust branch pipe, the second exhaust branch pipe, and the exhaust pipe are all made of low-carbon stainless steel, and the inner wall of the stainless steel pipe is electrolytically polished.

[0025] By adopting the above technical solutions, the low-carbon stainless steel pipe ensures the strength of the pipeline, and the electrolytic polishing makes the inner wall of the pipe smoother and brighter, which is conducive to the flow of nitrogen.

[0026] In summary, this application includes the following beneficial technical effects:

[0027] This application, by setting up a backflush mechanism, a nitrogen main pipe, a nitrogen branch pipe, a first exhaust branch pipe, a second exhaust branch pipe, a first gas path check valve, and a first shut-off valve, enables two sets of nitrogen adsorption towers to share the same backflush mechanism, alternately perform adsorption and regeneration, complete oxygen-nitrogen separation, and more effectively make full use of the nitrogen in the pipeline, thus ensuring the purity of nitrogen production. Attached Figure Description

[0028] Figure 1This is a schematic diagram of the structure of Embodiment 1 of this application;

[0029] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this application.

[0030] Explanation of the labels in the diagram:

[0031] 1. Nitrogen main pipe; 2. First tee pipe; 3. Nitrogen branch pipe; 4. Second tee pipe; 5. First exhaust branch pipe; 6. First gas path check valve; 7. Third tee pipe; 8. Connecting pipe; 9. Second exhaust branch pipe; 10. First shut-off valve; 11. Four-way pipe; 12. Exhaust pipe; 13. Backflush pipe; 14. Second shut-off valve; 15. Second gas path check valve; 16. First loop pipe; 17. Second loop pipe; 18. Connecting pipe. Detailed Implementation

[0032] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0033] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0036] Example 1

[0037] Please see Figure 1A nitrogen outlet backflushing device for a nitrogen generator includes two main nitrogen pipes 1 located at the outlet of a nitrogen adsorption tower. Each end of the main nitrogen pipe 1 is fixedly fitted with a first tee pipe 2. A backflushing mechanism is provided between the two first tee pipes 2. The backflushing mechanism includes two backflushing pipes 13 respectively fixedly installed on the first tee pipes 2. A second shut-off valve 14 is fixedly installed on each of the two backflushing pipes 13. A first loop pipe 16 is fixedly installed at one opposite end of the two backflushing pipes 13. The first loop pipe 16 is made of low-carbon stainless steel, and the inner wall of the stainless steel pipe is electrolytically polished. Two spaced-apart second gas path one-way valves 15 are fixedly installed on the first loop pipe 16. The two second gas path one-way valves 15 face the same direction along the first loop pipe 16, and are located on opposite sides of the line connecting the two backflushing pipes 13.

[0038] Nitrogen branch pipes 3 are fixedly installed at the other ends of the two first three-way pipes 2. Second three-way pipes 4 are fixedly installed at the ends of the two nitrogen branch pipes 3. First exhaust branch pipes 5 are fixedly installed at the opposite ends of the two second three-way pipes 4. First gas one-way valves 6 are installed on the two first exhaust branch pipes 5, and the two first gas one-way valves 6 are distributed opposite each other. Third three-way pipes 7 are fixedly installed at the opposite ends of the two first exhaust branch pipes 5. Connecting pipes 8 are fixedly installed at the other ends of the two second three-way pipes 4. Second exhaust branch pipes 9 are fixedly installed at the other ends of the two second exhaust branch pipes 9. First shut-off valves 10 are fixedly installed on the two second exhaust branch pipes 9. Four-way pipes 11 are fixedly installed at the opposite ends of the two second exhaust branch pipes 9. One end of connecting pipe 8 is fixedly connected to four-way pipe 11. Exhaust pipe 12 is fixedly installed at the other end of four-way pipe 11.

[0039] The nitrogen main pipe 1, nitrogen branch pipe 3, backflush pipe 13, first exhaust branch pipe 5, second exhaust branch pipe 9, and exhaust pipe 12 are all made of low-carbon stainless steel, ensuring the strength of the pipeline. The inner wall of the stainless steel pipe is electrolytically polished, making the inner wall of the pipeline smoother and brighter, which is conducive to the flow of nitrogen. The first gas path check valve 6, the first shut-off valve 10, the second shut-off valve 14, and the second gas path check valve 15 are all equipped with electrical control units. Each electrical control unit is controlled globally through a PLC controller, which enables more efficient and timely coordinated control of each valve body.

[0040] The implementation principle of this embodiment is as follows: Clean air raw material first enters one of the nitrogen adsorption towers, where O2, CO2, and H2O are adsorbed by the adsorbent. When the adsorbent in the nitrogen adsorption tower is saturated with oxygen, the inlet valve of the nitrogen adsorption tower is closed, and the inlet valve of the other nitrogen adsorption tower is opened. At the same time, the first gas path check valve 6 and the first shut-off valve 10 on the corresponding side of the original nitrogen adsorption tower are opened to depressurize the adsorption tower. Nitrogen is output from the first exhaust branch pipe 5, the second exhaust branch pipe 9, and the exhaust pipe 12 on the corresponding side. In conjunction with opening the second gas path check valve 15 and the second shut-off valve 14 on the corresponding side, nitrogen flows into the first loop pipe 16 through the backflush pipe 13. When the first loop pipe 16 is filled with nitrogen, the second shut-off valve on the corresponding side is closed. When the nitrogen in the nitrogen main pipe 1, nitrogen branch pipe 3, first exhaust branch pipe 5 and second exhaust branch pipe 9 is about to be completely discharged, the first shut-off valve 10 on the corresponding side is closed and the second shut-off valve 14 on the corresponding side is opened, so that the nitrogen in the first loop pipe 16 flows out. Part of the nitrogen flows out through the backflush pipe 13, nitrogen branch pipe 3, first exhaust branch pipe 5 and first gas one-way valve 6, and part of the nitrogen flows back into the nitrogen adsorption tower through the backflush pipe 13 and nitrogen main pipe 1 to desorb the adsorbed O2, CO2 and H2O, and realize the deoxygenation and regeneration of the adsorbent. The two sets of nitrogen adsorption towers share the same set of backflush mechanism, and alternately perform adsorption and regeneration to complete oxygen and nitrogen separation, which can make more effective use of the nitrogen in the pipeline and ensure the purity of nitrogen production.

[0041] Example 2

[0042] Please see Figure 2 A nitrogen generator nitrogen outlet backflushing device includes two nitrogen main pipes 1 located at the outlet of a nitrogen adsorption tower. Each end of the two nitrogen main pipes 1 is fixedly equipped with a first three-way pipe 2. A backflushing mechanism is provided between the two first three-way pipes 2. The backflushing mechanism includes two backflushing pipes 13 respectively fixedly installed on the first three-way pipes 2. A second shut-off valve 14 is fixedly installed on each of the two backflushing pipes 13. A second loop pipe 17 is fixedly installed at one opposite end of each of the two backflushing pipes 13. A connecting pipe 18 is fixedly installed between the two second loop pipes 17. Both the second loop pipes 17 and the connecting pipe 18 are made of low-carbon stainless steel, and the inner walls of the stainless steel pipes are electrolytically polished. Two spaced second gas path one-way valves 15 are fixedly installed on each of the two second loop pipes 17. The two second gas path one-way valves 15 located on the same second loop pipe 17 face the same direction along the second loop pipe 17, and are located on opposite sides of the connecting pipe 18.

[0043] Nitrogen branch pipes 3 are fixedly installed at the other ends of the two first three-way pipes 2. Second three-way pipes 4 are fixedly installed at the ends of the two nitrogen branch pipes 3. First exhaust branch pipes 5 are fixedly installed at the opposite ends of the two second three-way pipes 4. First gas one-way valves 6 are installed on the two first exhaust branch pipes 5, and the two first gas one-way valves 6 are distributed opposite each other. Third three-way pipes 7 are fixedly installed at the opposite ends of the two first exhaust branch pipes 5. Connecting pipes 8 are fixedly installed at the other ends of the two second three-way pipes 4. Second exhaust branch pipes 9 are fixedly installed at the other ends of the two second exhaust branch pipes 9. First shut-off valves 10 are fixedly installed on the two second exhaust branch pipes 9. Four-way pipes 11 are fixedly installed at the opposite ends of the two second exhaust branch pipes 9. One end of connecting pipe 8 is fixedly connected to four-way pipe 11. Exhaust pipe 12 is fixedly installed at the other end of four-way pipe 11.

[0044] The nitrogen main pipe 1, nitrogen branch pipe 3, backflush pipe 13, first exhaust branch pipe 5, second exhaust branch pipe 9, and exhaust pipe 12 are all made of low-carbon stainless steel, ensuring the strength of the pipeline. The inner wall of the stainless steel pipe is electrolytically polished, making the inner wall of the pipeline smoother and brighter, which is conducive to the flow of nitrogen. The first gas path check valve 6, the first shut-off valve 10, the second shut-off valve 14, and the second gas path check valve 15 are all equipped with electrical control units. Each electrical control unit is controlled globally through a PLC controller, which enables more efficient and timely coordinated control of each valve body.

[0045] The implementation principle of this embodiment is as follows: Clean air raw material first enters one of the nitrogen adsorption towers, where O2, CO2, and H2O are adsorbed by the adsorbent. When the adsorbent in the nitrogen adsorption tower is saturated with oxygen, the inlet valve of the nitrogen adsorption tower is closed, and the inlet valve of the other nitrogen adsorption tower is opened. At the same time, the first gas path check valve 6 and the first shut-off valve 10 on the corresponding side of the original nitrogen adsorption tower are opened to depressurize the adsorption tower. Nitrogen is output from the first exhaust branch pipe 5, the second exhaust branch pipe 9, and the exhaust pipe 12 on the corresponding side. In conjunction with opening the second gas path check valve 15 and the corresponding second shut-off valve 14, nitrogen flows into the second loop pipe 17 through the backflush pipe 13. The two second loop pipes 17 are connected by a connecting pipe 18 to achieve the interactive flow of nitrogen. Once the two second loop pipes 17 are full... When nitrogen is being used, the second shut-off valve 14 on the corresponding side is closed. When the nitrogen in the nitrogen main pipe 1, nitrogen branch pipe 3, first exhaust branch pipe 5 and second exhaust branch pipe 9 is about to be completely discharged, the first shut-off valve 10 on the corresponding side is closed and the second shut-off valve 14 on the corresponding side is opened, so that the nitrogen in the two second loop pipes 17 flows out. Part of the nitrogen flows out through the backflush pipe 13, nitrogen branch pipe 3, first exhaust branch pipe 5 and first gas one-way valve 6, and part of the nitrogen flows back into the nitrogen adsorption tower through the backflush pipe 13 and nitrogen main pipe 1 to desorb the adsorbed O2, CO2 and H2O, and realize the deoxygenation and regeneration of the adsorbent. The two sets of nitrogen adsorption towers share the same set of backflush mechanism, and alternately perform adsorption and regeneration to complete oxygen and nitrogen separation. This can make more effective use of the nitrogen in the pipeline and ensure the purity of nitrogen production.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A nitrogen outlet backflush device for a nitrogen generator, comprising two nitrogen main pipes (1) arranged at the outlet of a nitrogen adsorption tower, characterized in that: The ends of the two nitrogen main pipes (1) are fixedly provided with first three-way pipes (2), the two first three-way pipes (2) are provided with back flushing mechanisms, the back flushing mechanism comprises two back flushing pipes (13) fixedly provided on the first three-way pipes (2), the two back flushing pipes (13) are fixedly provided with second stop valves (14), the opposite ends of the two back flushing pipes (13) are fixedly provided with a first back ring pipe (16), the first back ring pipe (16) is fixedly provided with two second air path check valves (15) which are spaced apart, the two second air path check valves (15) are the same in direction along the first back ring pipe (16), and the two second air path check valves (15) are located on the two sides of the line connecting the two back flushing pipes (13), the other ends of the two first three-way pipes (2) are fixedly provided with nitrogen branch pipes (3), the ends of the two nitrogen branch pipes (3) are fixedly provided with second three-way pipes (4), the opposite ends of the two second three-way pipes (4) are fixedly provided with first exhaust branch pipes (5), the two first exhaust branch pipes (5) are provided with first air path check valves (6), and the two first air path check valves (6) are oppositely distributed, the opposite ends of the two first exhaust branch pipes (5) are fixedly provided with a third three-way pipe (7), the other end of the third three-way pipe (7) is fixedly provided with a connecting pipe (8), the other ends of the two second three-way pipes (4) are fixedly provided with second exhaust branch pipes (9), the two second exhaust branch pipes (9) are fixedly provided with first stop valves (10), the opposite ends of the two second exhaust branch pipes (9) are fixedly provided with a four-way pipe (11), one end of the connecting pipe (8) is fixedly connected with the four-way pipe (11), the other end of the four-way pipe (11) is fixedly provided with an exhaust pipe (12), the second air path check valve (15) and the second stop valve (14) on the corresponding side are opened, so that the nitrogen flows into the first back ring pipe (16) through the back flushing pipe (13), when the first back ring pipe (16) is filled with nitrogen, the second stop valve (14) on the corresponding side is closed, when the nitrogen in the nitrogen main pipe (1), the nitrogen branch pipe (3), the first exhaust branch pipe (5) and the second exhaust branch pipe (9) is about to be exhausted, the first stop valve (10) on the corresponding side is closed, the second stop valve (14) on the corresponding side is opened, so that the nitrogen in the first back ring pipe (16) flows out, part of the nitrogen flows out through the back flushing pipe (13), the nitrogen branch pipe (3), the first exhaust branch pipe (5) and the first air path check valve (6), and part of the nitrogen flows back into the nitrogen adsorption tower through the back flushing pipe (13) and the nitrogen main pipe (1).

2. The nitrogen outlet backflush device of claim 1, wherein: The first back ring pipe (16) is a low-carbon stainless steel pipe, and the inner wall of the stainless steel pipe is electrolytically polished.

3. The nitrogen outlet backflush device of claim 1, wherein: The nitrogen main pipe (1), the nitrogen branch pipe (3) and the back flushing pipe (13) are all low-carbon stainless steel pipes, and the inner walls of the stainless steel pipes are electrolytically polished.

4. The nitrogen outlet backflush device of claim 1, wherein: The first gas path one-way valve (6), the first stop valve (10), the second stop valve (14) and the second gas path one-way valve (15) are all provided with an electric control unit, and the electric control units are globally controlled through a PLC controller.

5. The nitrogen outlet backflush device of claim 1, wherein: The first exhaust branch pipe (5), the second exhaust branch pipe (9) and the exhaust pipe (12) are all low-carbon stainless steel pipes, and the inner walls of the stainless steel pipes are electrolytically polished.

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