Comprehensive recycling system for waste gas of pressure swing adsorption nitrogen making device

Abstract

The invention discloses a comprehensive recycling system for waste gas of a pressure swing adsorption nitrogen making device. The comprehensive recycling system comprises an air compressor, a refrigerated dryer, a first filter, a drying tower unit, a second filter, an air storage tank, an adsorption tower unit and a nitrogen storage tank which are sequentially connected through a pipeline, the drying tower unit comprises drying towers arranged in parallel, the inlet ends of the drying towers are connected with the first filter, and the outlet ends of the drying towers are connected with the second filter; the adsorption tower unit comprises adsorption towers arranged in parallel, the inlet ends of the adsorption towers are connected with an air storage tank, the outlet ends of the adsorption towers are connected with a nitrogen storage tank, and the nitrogen storage tank is provided with a nitrogen back-blowing pipe connected with the adsorption towers; a recovery pipe connected with the waste gas storage tank is arranged on the adsorption tower inlet switching pipeline, and a waste gas blowback pipe connected with the drying tower and an oxygen-enriched waste gas pipe connected with a boiler air inlet pipe are arranged at an outlet of the waste gas storage tank. The system is simple in structure and easy to implement, the cost is low when an existing nitrogen making device is transformed, and the energy consumption of the system can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of nitrogen production, and in particular to a comprehensive recovery and utilization system for waste gas of a pressure swing adsorption nitrogen production device. Background Art

[0002] Nitrogen accounts for more than 70% of the volume of air, and its chemical properties are relatively stable. In the industrial field, nitrogen is used in large quantities. The molecular sieve pressure swing adsorption method uses compressed air as raw material and carbon molecular sieve as adsorbent. It uses the principle of pressure swing adsorption and utilizes the selective adsorption of carbon molecular sieve to oxygen and nitrogen to separate oxygen and nitrogen, thereby producing nitrogen. The device using this method has the characteristics of simple process route, high degree of automation, and high purity of the obtained nitrogen, so it is widely used. However, the regeneration of the desiccant in its air drying tower requires a large amount of compressed air. At the same time, the molecular sieve adsorption tower will discharge a large amount of exhaust gas when backblowing and depressurizing, wasting a lot of residual pressure and oxygen-rich air. Summary of the invention

[0003] In view of the above problems, the present invention provides a comprehensive recovery and utilization system for waste gas from a pressure swing adsorption nitrogen production device, which can specifically adopt the following technical solutions: The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen production device of the present invention comprises an air compressor, a refrigerated dryer, a first filter, a drying tower unit, a second filter, an air storage tank, an adsorption tower unit and a nitrogen storage tank which are sequentially connected through pipelines; the drying tower unit comprises a plurality of drying towers arranged in parallel, the inlet end of the drying tower is connected to the outlet pipe of the first filter through a first inlet switching pipeline, a vent pipe is arranged on the first inlet switching pipeline, and the outlet end of the drying tower is connected to the inlet pipe of the second filter through the first outlet switching pipeline; the adsorption tower unit comprises a plurality of drying towers arranged in parallel, the inlet end of the drying tower is connected to the outlet pipe of the first filter through a first inlet switching pipeline, a vent pipe is arranged on the first inlet switching pipeline, and the outlet end of the drying tower is connected to the inlet pipe of the second filter through the first outlet switching pipeline; The auxiliary tower unit includes several adsorption towers arranged in parallel, the inlet end of the adsorption tower is connected to the outlet pipe of the air storage tank through the second inlet switching pipeline, the outlet end of the adsorption tower is connected to the inlet pipe of the nitrogen storage tank through the second outlet switching pipeline, and the outlet pipe of the nitrogen storage tank is connected to the second outlet switching pipeline through a nitrogen backflush pipe; a recovery pipe is arranged on the second inlet switching pipeline, the recovery pipe is connected to the inlet of the waste gas storage tank, and the outlet of the waste gas storage tank is respectively provided with a waste gas backflush pipe connected to the first outlet switching pipeline, and an oxygen-enriched waste gas pipe connected to the boiler air inlet pipe.

[0004] Preferably, the drying tower unit comprises a drying tower A and a drying tower B arranged in parallel; the first inlet switching pipeline comprises a first intake branch pipe A and a first intake branch pipe B connected to the first filter outlet pipe, the first intake branch pipe A is connected to the inlet of the drying tower A, the first intake branch pipe A is provided with a first intake valve A and an exhaust branch pipe A located behind the valve, the first intake branch pipe B is connected to the inlet of the drying tower B, the first intake branch pipe B is provided with a first intake valve B and an exhaust branch pipe B located behind the valve, the exhaust branch pipe A is provided with an exhaust valve A, the exhaust branch pipe B is provided with an exhaust valve B, the exhaust branch pipe A and the exhaust branch pipe B are connected, and the vent pipe is provided between the exhaust valve A and the exhaust valve B; the first The outlet switching pipeline includes a first air outlet branch pipe A connected to the outlet of the drying tower A and a first air outlet branch pipe B connected to the outlet of the drying tower B. The first air outlet branch pipe A is provided with a first air outlet valve A and an exhaust gas backflush branch pipe A located in front of the valve, the first air outlet branch pipe B is provided with a first air outlet valve B and an exhaust gas backflush branch pipe B located in front of the valve, the first air outlet branch pipe A is connected to the first air outlet branch pipe B, the inlet pipe of the second filter is arranged between the first air outlet valve A and the first air outlet valve B, the exhaust gas backflush valve A is arranged on the exhaust gas backflush branch pipe A, the exhaust gas backflush valve B is arranged on the exhaust gas backflush branch pipe B, the exhaust gas backflush branch pipe A is connected to the exhaust gas backflush branch pipe B, and the exhaust gas backflush pipe is arranged between the exhaust gas backflush valve A and the exhaust gas backflush valve B.

[0005] Furthermore, the first outlet switching pipeline also includes an exhaust gas backflush switching pipe connecting the drying tower A and the drying tower B, and an exhaust gas backflush switching valve is provided on the exhaust gas switching pipe.

[0006] Preferably, the adsorption tower unit includes an adsorption tower A and an adsorption tower B arranged in parallel; the second inlet switching pipeline includes a second air intake branch pipe A and a second air intake branch pipe B connected to the air storage tank outlet pipe, the second air intake branch pipe A is connected to the inlet of the adsorption tower A, the second air intake branch pipe A is provided with a second air intake valve A and a recovery branch pipe A located behind the valve, the second air intake branch pipe B is connected to the inlet of the adsorption tower B, the second air intake branch pipe B is provided with a second air intake valve B and a recovery branch pipe B located behind the valve, the recovery branch pipe A is provided with a recovery valve A, the recovery branch pipe B is provided with a recovery valve B, the recovery branch pipe A and the recovery branch pipe B are connected, and the recovery pipe is arranged between the recovery valve A and the recovery valve B; the second The outlet switching pipeline includes a second outlet branch pipe A connected to the outlet of the adsorption tower A and a second outlet branch pipe B connected to the outlet of the adsorption tower B. The second outlet branch pipe A is provided with a second outlet valve A and a nitrogen backflush branch pipe A located in front of the valve. The second outlet branch pipe B is provided with a second outlet valve B and a nitrogen backflush branch pipe B located in front of the valve. The second outlet branch pipe A is connected to the second outlet branch pipe B. The inlet pipe of the nitrogen storage tank is arranged between the second outlet valve A and the second outlet valve B. The nitrogen backflush valve A is arranged on the nitrogen backflush branch pipe A. The nitrogen backflush valve B is arranged on the nitrogen backflush branch pipe B. The nitrogen backflush branch pipe A is connected to the nitrogen backflush branch pipe B. The nitrogen backflush pipe is arranged between the nitrogen backflush valve A and the nitrogen backflush valve B.

[0007] Furthermore, the second outlet switching pipeline also includes a nitrogen backflush switching pipe connecting the adsorption tower A and the adsorption tower B, and a nitrogen backflush switching valve is provided on the nitrogen switching pipe.

[0008] Preferably, the gas pressure in the waste gas storage tank is 0.6~0.7MPa, and the oxygen content is 35~40%.

[0009] Preferably, a blower is provided on the boiler air inlet pipe, and a first pressure reducing valve is provided on the oxygen-enriched exhaust gas pipe.

[0010] Preferably, a second pressure reducing valve is provided on the exhaust gas blowback pipe, the gas pressure after the second pressure reducing valve is 0.1 MPa, and the oxygen content of the exhaust gas is 35-40%.

[0011] The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen production device provided by the present invention recycles waste gas when a molecular sieve adsorption tower is back-blown and depressurized, and utilizes the waste gas for two purposes: first, the waste gas is collected and sent to an adsorption dryer for regeneration and back-blowing of a desiccant in the drying tower, replacing the use of dried compressed air in a conventional process; second, the collected waste gas is decompressed and sent to the outlet of a boiler blower, mixed with the air blown in by the blower, and then sent to the boiler to be burned together with fuel, thereby reducing the overall energy consumption of the device.

[0012] The present invention has a simple structure and is easy to implement. When the existing nitrogen production device is modified, the cost is low. Compared with the prior art, the advantages of the present invention are as follows: 1) Using waste gas instead of dried compressed air for regeneration and backwashing of desiccant in the drying tower saves dry compressed air, improves nitrogen production efficiency and reduces operating costs; 2) Introducing exhaust gas into the boiler as oxygen-enriched air for combustion can increase the fuel combustion temperature in the boiler and improve heat utilization efficiency; 3) The exhaust gas has a certain residual pressure. After being decompressed, it is sent into the air duct at the rear end of the blower to reduce the power consumption of the blower; 4) The use of oxygen-enriched combustion in the boiler can reduce the emission of NOx in the flue gas, bringing environmental benefits; 5) The use of oxygen-enriched combustion in the boiler can reduce the amount of flue gas, reduce the heat loss carried away by the flue gas, and improve the thermal efficiency of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0014] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific working process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0015] like Figure 1 As shown, the comprehensive recovery and utilization system for waste gas from a pressure swing adsorption nitrogen production device according to the present invention comprises: The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen production device of the present invention comprises an air compressor 1, a refrigerated dryer 2, a first filter 3, a drying tower unit, a second filter 4, an air storage tank 5, an adsorption tower unit and a nitrogen storage tank 6 which are sequentially connected through pipelines, wherein the drying tower unit comprises a plurality of drying towers arranged in parallel (two in this embodiment, namely, a drying tower A701 and a drying tower B702), the inlet end of the drying tower is connected to the outlet pipe of the first filter 3 through a first inlet switching pipeline, a vent pipe 703 is arranged on the first inlet switching pipeline, and the outlet end of the drying tower is connected to the inlet pipe of the second filter 4 through the first outlet switching pipeline; the adsorption tower unit The element includes several adsorption towers arranged in parallel (two in the present embodiment, namely, adsorption tower A801 ​​and adsorption tower B802), the inlet end of the above-mentioned adsorption tower is connected to the outlet pipe of the air storage tank 5 through the second inlet switching pipeline, the outlet end of the adsorption tower is connected to the inlet pipe of the nitrogen storage tank 6 through the second outlet switching pipeline, and the outlet pipe of the nitrogen storage tank 6 is connected to the second outlet switching pipeline through the nitrogen backflush pipe 601; a recovery pipe 803 is arranged on the second inlet switching pipeline, the recovery pipe 803 is connected to the inlet of the waste gas storage tank 9, and the outlet of the waste gas storage tank 9 is respectively provided with a waste gas backflush pipe 901 connected to the first outlet switching pipeline, and an oxygen-enriched waste gas pipe 902 connected to the air inlet pipe of the boiler 10.

[0016] Specifically, the drying tower unit includes a drying tower A701 and a drying tower B702 arranged in parallel; the first inlet switching pipeline includes a first air intake branch pipe A and a first air intake branch pipe B connected to the outlet pipe of the first filter 3, the first air intake branch pipe A is connected to the inlet of the drying tower A701, the first air intake branch pipe A is provided with a first air intake valve A704 and an emptying branch pipe A located behind the valve, the first air intake branch pipe B is connected to the inlet of the drying tower B702, the first air intake branch pipe B is provided with a first air intake valve B705 and an emptying branch pipe B located behind the valve, the emptying branch pipe A is provided with an emptying valve A706, the emptying branch pipe B is provided with an emptying valve B707, the emptying branch pipe A is connected to the emptying branch pipe B, and the vent pipe 703 is provided between the emptying valve A706 and the emptying valve B707; the first outlet The port switching pipeline includes a first air outlet branch pipe A connected to the outlet of the drying tower A701 and a first air outlet branch pipe B connected to the outlet of the drying tower B702. The first air outlet branch pipe A is provided with a first air outlet valve A708 and an exhaust gas backflush branch pipe A located in front of the valve. The first air outlet branch pipe B is provided with a first air outlet valve B709 and an exhaust gas backflush branch pipe B located in front of the valve. The first air outlet branch pipe A is connected to the first air outlet branch pipe B. The inlet pipe of the second filter 4 is arranged between the first air outlet valve A708 and the first air outlet valve B709. The exhaust gas backflush branch pipe A is provided with an exhaust gas backflush valve A710. The exhaust gas backflush branch pipe B is provided with an exhaust gas backflush valve B711. The exhaust gas backflush branch pipe A is connected to the exhaust gas backflush branch pipe B. The exhaust gas backflush pipe 901 is arranged between the exhaust gas backflush valve A710 and the exhaust gas backflush valve B711. Furthermore, the first outlet switching pipeline also includes an exhaust gas backflush switching pipe connecting the drying tower A 701 and the drying tower B 702 , and an exhaust gas backflush switching valve 712 is provided on the exhaust gas switching pipe.

[0017] The above-mentioned adsorption tower unit includes an adsorption tower A801 ​​and an adsorption tower B802 arranged in parallel; the above-mentioned second inlet switching pipeline includes a second air intake branch pipe A and a second air intake branch pipe B connected to the outlet pipe of the air storage tank 5, the second air intake branch pipe A is connected to the inlet of the adsorption tower A801, the second air intake branch pipe A is provided with a second air intake valve A804 and a recovery branch pipe A located behind the valve, the second air intake branch pipe B is connected to the inlet of the adsorption tower B802, the second air intake branch pipe B is provided with a second air intake valve B805 and a recovery branch pipe B located behind the valve, the recovery branch pipe A is provided with a recovery valve A806, the recovery branch pipe B is provided with a recovery valve B807, the recovery branch pipe A is connected to the recovery branch pipe B, and the recovery pipe 803 is arranged between the recovery valve A806 and the recovery valve B807; the above-mentioned second outlet The switching pipeline includes a second gas outlet branch A connected to the outlet of the adsorption tower A801 ​​and a second gas outlet branch B connected to the outlet of the adsorption tower B802. The second gas outlet branch A is provided with a second gas outlet valve A808 and a nitrogen backflush branch A located in front of the valve. The second gas outlet branch B is provided with a second gas outlet valve B809 and a nitrogen backflush branch B located in front of the valve. The second gas outlet branch A is connected to the second gas outlet branch B. The inlet pipe of the nitrogen storage tank 6 is arranged between the second gas outlet valve A808 and the second gas outlet valve B809. The nitrogen backflush branch A is provided with a nitrogen backflush valve A810. The nitrogen backflush branch B is provided with a nitrogen backflush valve B811. The nitrogen backflush branch A is connected to the nitrogen backflush branch B. The nitrogen backflush pipe is arranged between the nitrogen backflush valve A810 and the nitrogen backflush valve B811. Furthermore, the second outlet switching pipeline also includes a nitrogen backflush switching pipe connecting the adsorption tower A801 ​​and the adsorption tower B802, and a nitrogen backflush switching valve 812 is provided on the nitrogen switching pipe.

[0018] Normally, the gas pressure in the waste gas storage tank 9 is 0.6-0.7 MPa, and the oxygen content is 35-40%. A blower 11 is provided on the air inlet pipe of the boiler 10, and a first pressure reducing valve 903 is provided on the oxygen-enriched waste gas pipe 902. A second pressure reducing valve 904 is provided on the waste gas blowback pipe 901, and the gas pressure after the second pressure reducing valve 904 is 0.1 MPa.

[0019] During operation, air enters the refrigerated dryer 2 from the air compressor 1 to complete preliminary drying, so as to reduce the erosion of the molecular sieve in the drying tower unit by water and extend the service life of the molecular sieve. After that, the compressed air passes through the first filter 3 and enters the drying tower unit. In the above-mentioned drying tower unit, through the automatic switching of the opening and closing states of the first air inlet valve A704, the first air inlet valve B705, the exhaust valve A706, the exhaust valve B707, the first air outlet valve A708, the first air outlet valve B709, the exhaust gas backflush valve A710, and the exhaust gas backflush valve B711, the drying tower A701 and the drying tower B702 are kept dry in one tower and the exhaust gas backflush in the other tower, so as to realize the regeneration of the desiccant in the tower. The compressed air discharged from the drying tower unit enters the air storage tank 5 through the second filter 4, and then enters the adsorption tower unit. In the above-mentioned adsorption tower unit, through the automatic switching of the opening and closing states of the second air inlet valve A804, the second air inlet valve B805, the recovery valve A806, the recovery valve B807, the second air outlet valve A808, the second air outlet valve B809, the nitrogen backflush valve A810, and the nitrogen backflush valve B811, the adsorption tower A801 ​​and the adsorption tower B802 are kept in one tower for boost adsorption, the generated nitrogen enters the nitrogen storage tank 6 for storage, and the other tower performs nitrogen backflush to achieve the regeneration of the adsorbent in the tower. Each of the above-mentioned adsorption towers includes three working stages of boost adsorption, pressure relief, and backflush regeneration, and different purity nitrogen can be produced by setting different adsorption times. Most of the nitrogen in the nitrogen storage tank 6 is output as finished nitrogen, and a small part returns to the adsorption tower unit through the nitrogen backflush pipe to perform nitrogen backflush of the adsorption tower. After the nitrogen backflush is completed, the waste gas discharged from the adsorption tower has a high pressure (about 0.6~0.7MPa) and is rich in oxygen (the volume content of oxygen is 35~40%). Therefore, this part of the waste gas is introduced into the waste gas storage tank 9 for two uses: first, the waste gas is sent to the drying tower unit for regeneration backflush of the desiccant in the drying tower (see the above steps for details), replacing the conventional process of using dry compressed air for backflush, avoiding the consumption of nitrogen in the system, and increasing the nitrogen production of the system; second, the collected waste gas is decompressed and sent to the air inlet pipe of the boiler 10, mixed with the air blown by the blower 11, and then sent to the boiler 10 for combustion together with the fuel.

[0020] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships, such as "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

Claims

1. A comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen production device, characterized in that: It includes an air compressor, a refrigerated dryer, a first filter, a drying tower unit, a second filter, an air storage tank, an adsorption tower unit and a nitrogen storage tank which are sequentially connected through pipelines; The drying tower unit comprises a plurality of drying towers arranged in parallel, the inlet end of the drying tower is connected to the outlet pipe of the first filter through a first inlet switching pipeline, a vent pipe is arranged on the first inlet switching pipeline, and the outlet end of the drying tower is connected to the inlet pipe of the second filter through the first outlet switching pipeline; The adsorption tower unit comprises a plurality of adsorption towers arranged in parallel, the inlet end of the adsorption tower is connected to the outlet pipe of the air storage tank through a second inlet switching pipeline, the outlet end of the adsorption tower is connected to the inlet pipe of the nitrogen storage tank through a second outlet switching pipeline, and the outlet pipe of the nitrogen storage tank is connected to the second outlet switching pipeline through a nitrogen backflush pipe; A recovery pipe is provided on the second inlet switching pipeline, and the recovery pipe is connected to the inlet of the exhaust gas storage tank. The outlet of the exhaust gas storage tank is respectively provided with an exhaust gas backflush pipe connected to the first outlet switching pipeline and an oxygen-enriched exhaust gas pipe connected to the boiler air inlet pipe.

2. The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen generator according to claim 1 is characterized in that: The drying tower unit comprises a drying tower A and a drying tower B arranged in parallel; The first inlet switching pipeline includes a first intake branch pipe A and a first intake branch pipe B connected to the first filter outlet pipe, the first intake branch pipe A is connected to the inlet of the drying tower A, the first intake branch pipe A is provided with a first intake valve A and an exhaust branch pipe A located behind the valve, the first intake branch pipe B is connected to the inlet of the drying tower B, the first intake branch pipe B is provided with a first intake valve B and an exhaust branch pipe B located behind the valve, the exhaust branch pipe A is provided with an exhaust valve A, the exhaust branch pipe B is provided with an exhaust valve B, the exhaust branch pipe A and the exhaust branch pipe B are connected, and the vent pipe is provided between the exhaust valve A and the exhaust valve B; The first outlet switching pipeline includes a first air outlet branch pipe A connected to the outlet of the drying tower A and a first air outlet branch pipe B connected to the outlet of the drying tower B. The first air outlet branch pipe A is provided with a first air outlet valve A and an exhaust gas backflush branch pipe A located in front of the valve. The first air outlet branch pipe B is provided with a first air outlet valve B and an exhaust gas backflush branch pipe B located in front of the valve. The first air outlet branch pipe A is connected to the first air outlet branch pipe B. The inlet pipe of the second filter is arranged between the first air outlet valve A and the first air outlet valve B. The exhaust gas backflush valve A is arranged on the exhaust gas backflush branch pipe A. The exhaust gas backflush valve B is arranged on the exhaust gas backflush branch pipe B. The exhaust gas backflush branch pipe A is connected to the exhaust gas backflush branch pipe B. The exhaust gas backflush pipe is arranged between the exhaust gas backflush valve A and the exhaust gas backflush valve B.

3. The comprehensive recovery and utilization system for waste gas from a pressure swing adsorption nitrogen generator according to claim 2 is characterized in that: The first outlet switching pipeline also includes an exhaust gas backflush switching pipe connecting the drying tower A and the drying tower B, and an exhaust gas backflush switching valve is provided on the exhaust gas switching pipe.

4. The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen generator according to claim 1 is characterized in that: The adsorption tower unit comprises an adsorption tower A and an adsorption tower B arranged in parallel; The second inlet switching pipeline includes a second air intake branch pipe A and a second air intake branch pipe B connected to the air storage tank outlet pipe, the second air intake branch pipe A is connected to the inlet of the adsorption tower A, the second air intake branch pipe A is provided with a second air intake valve A and a recovery branch pipe A located behind the valve, the second air intake branch pipe B is connected to the inlet of the adsorption tower B, the second air intake branch pipe B is provided with a second air intake valve B and a recovery branch pipe B located behind the valve, the recovery branch pipe A is provided with a recovery valve A, the recovery branch pipe B is provided with a recovery valve B, the recovery branch pipe A is connected to the recovery branch pipe B, and the recovery pipe is provided between the recovery valve A and the recovery valve B; The second outlet switching pipeline includes a second outlet branch pipe A connected to the outlet of the adsorption tower A and a second outlet branch pipe B connected to the outlet of the adsorption tower B. The second outlet branch pipe A is provided with a second outlet valve A and a nitrogen backflush branch pipe A located in front of the valve. The second outlet branch pipe B is provided with a second outlet valve B and a nitrogen backflush branch pipe B located in front of the valve. The second outlet branch pipe A is connected to the second outlet branch pipe B. The inlet pipe of the nitrogen storage tank is arranged between the second outlet valve A and the second outlet valve B. The nitrogen backflush valve A is arranged on the nitrogen backflush branch pipe A. The nitrogen backflush valve B is arranged on the nitrogen backflush branch pipe B. The nitrogen backflush branch pipe A is connected to the nitrogen backflush branch pipe B. The nitrogen backflush pipe is arranged between the nitrogen backflush valve A and the nitrogen backflush valve B.

5. The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen generator according to claim 4 is characterized in that: The second outlet switching pipeline also includes a nitrogen backflush switching pipe connecting the adsorption tower A and the adsorption tower B, and a nitrogen backflush switching valve is provided on the nitrogen switching pipe.

6. The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen generator according to claim 1 is characterized in that: The gas pressure in the waste gas storage tank is 0.6~0.7MPa, and the oxygen content is 35~40%.

7. The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen generator according to claim 1 is characterized in that: The boiler air inlet pipe is provided with a blower, and the oxygen-enriched exhaust gas pipe is provided with a first pressure reducing valve.

8. The comprehensive recycling system for waste gas from a pressure swing adsorption nitrogen generator according to claim 1 is characterized in that: The exhaust gas blowback pipe is provided with a second pressure reducing valve, and the gas pressure after the second pressure reducing valve is 0.1 MPa.

Images