A PSA nitrogen generating device pressure maintaining pipeline and PSA nitrogen generating device

Abstract

The utility model relates to the field of nitrogen making device, concretely relates to a PSA nitrogen making device pressure -sustaining pipeline and PSA nitrogen making device, wherein the pressure -sustaining pipeline includes reflux pipe, PLC controller and pressure gauge, the pneumatic regulating valve is equipped on the reflux pipe, the reflux pipe is used to connect nitrogen gas pipe network and nitrogen gas buffer tank, the pressure gauge is used for monitoring nitrogen gas buffer tank pressure, the pressure gauge and pneumatic regulating valve are electrically connected with PLC controller respectively. During the shutdown of PSA nitrogen making device, the pressure of nitrogen gas buffer tank is monitored in real time, when the pressure of nitrogen gas buffer tank drops below the normal range, nitrogen gas is transported to nitrogen gas buffer tank through reflux pipe, the internal pressure of nitrogen gas buffer tank is kept in the normal range, thereby the outside air can be avoided to enter nitrogen gas buffer tank, when the PSA nitrogen making device starts next time, nitrogen gas buffer tank does not need to be vented, the starting efficiency of PSA nitrogen making device is improved, and the nitrogen gas supply to nitrogen gas pipe network is ensured.

Description

Technical Field

[0001] This utility model relates to the field of nitrogen generation equipment, and in particular to a pressure-maintaining pipeline for a PSA nitrogen generation equipment and a PSA nitrogen generation equipment. Background Technology

[0002] After a PSA (Pressure Swing Adsorption) nitrogen generator is shut down, the lack of continuous nitrogen supply, coupled with equipment aging, may lead to leakage of residual nitrogen in the nitrogen buffer tank. This can cause the nitrogen pressure in the buffer tank to become unsustainable, allowing outside air to easily enter. When restarting the PSA nitrogen generator, it is necessary to vent until the oxygen content is within acceptable limits before connecting it to the pipeline network. This startup process is slow, and during the venting period, the nitrogen production in the pipeline network is insufficient. Users need to replenish this nitrogen by consuming large amounts of liquid nitrogen, resulting in unnecessary production cost waste and potentially affecting the stability of the entire air supply network system.

[0003] Therefore, a technical solution is needed to address the problem that after a PSA nitrogen generator is shut down, due to the lack of continuous nitrogen replenishment and equipment aging, residual nitrogen in the nitrogen buffer tank will leak out, and outside air can easily enter the buffer tank. When restarting the PSA nitrogen generator, the nitrogen buffer tank needs to be emptied for a long time, resulting in insufficient nitrogen production to supply the nitrogen pipeline network. Utility Model Content

[0004] The purpose of this invention is to overcome the technical problem in the prior art that after a PSA nitrogen generator is shut down, due to the lack of continuous nitrogen replenishment and the aging of the equipment, the remaining nitrogen in the nitrogen buffer tank will leak out, and outside air can easily enter the buffer tank. When restarting the PSA nitrogen generator, the nitrogen buffer tank needs to be emptied for a long time, resulting in insufficient nitrogen production to supply the nitrogen pipeline network. The invention provides a pressure-maintaining pipeline for a PSA nitrogen generator and a PSA nitrogen generator.

[0005] In a first aspect, this utility model provides a pressure-maintaining pipeline for a PSA nitrogen generator, including a return pipe, a PLC controller, and a pressure gauge. The return pipe is equipped with a pneumatic regulating valve, and the return pipe is used to connect the nitrogen pipeline network and the nitrogen buffer tank. The pressure gauge is used to monitor the pressure of the nitrogen buffer tank. The pressure gauge and the pneumatic regulating valve are electrically connected to the PLC controller.

[0006] This utility model discloses a pressure-maintaining pipeline for a PSA nitrogen generator. During the shutdown period of the PSA nitrogen generator, a pressure gauge monitors the nitrogen pressure inside the nitrogen buffer tank and transmits the signal to the PLC controller. When the internal pressure of the nitrogen buffer tank is lower than the normal range of 0.5-0.6 MPa, the PLC controller controls the pneumatic regulating valve to open, introducing nitrogen from the nitrogen pipeline network into the nitrogen buffer tank through the return pipe. When the internal pressure of the nitrogen buffer tank is higher than the normal range of 0.5-0.6 MPa, the PLC controller controls the pneumatic regulating valve to close, thereby preventing excessive nitrogen pressure inside the nitrogen buffer tank and aggravating nitrogen loss. This maintains the internal pressure of the nitrogen buffer tank within the range of 0.5-0.6 MPa, preventing outside air from entering the nitrogen buffer tank. When the PSA nitrogen generator is restarted, it is not necessary to vent the nitrogen buffer tank, improving the startup efficiency of the PSA nitrogen generator and ensuring the nitrogen supply to the nitrogen pipeline network.

[0007] Preferably, the return pipe is further provided with a throttle valve, which is located downstream of the pneumatic regulating valve.

[0008] The core function of a throttle valve is to limit the maximum flow rate of returning nitrogen or provide a fixed resistance through mechanical flow restriction. Once set, the opening degree is fixed to prevent excessive flow when the pneumatic regulating valve fails. It can reduce the flow rate of high-pressure nitrogen and reduce the impact on the buffer tank.

[0009] Preferably, the return pipe is further provided with a first one-way valve, which is located downstream of the throttle valve.

[0010] To prevent nitrogen from flowing back into the nitrogen pipeline from the buffer tank, it isolates pressure fluctuations, protects return pipeline equipment (such as throttle valves and pressure regulating valves) from reverse pressure impacts, and maintains stable system pressure. The zero-reverse-leakage characteristic of the check valve complements the flow restriction of the throttle valve and the pressure regulation of the pneumatic regulating valve. The throttle valve controls the upper limit of the forward flow, the pressure regulating valve stabilizes the downstream pressure, and the check valve ensures unidirectional flow and eliminates reverse interference.

[0011] Preferably, the reflux pipe is further provided with a diversion pipe, which is used to connect the adsorption tower backflush pipe and is connected between the first one-way valve and the throttling valve.

[0012] The nitrogen from the nitrogen pipeline can be introduced into adsorption towers A and B through the diversion pipe to maintain the pressure of the adsorption towers and further reduce the venting time.

[0013] Preferably, the diversion pipe is provided with a second one-way valve.

[0014] The second check valve has the same function as the first check valve. On the one hand, it prevents nitrogen from flowing back into the nitrogen pipeline from the adsorption tower. On the other hand, it works in conjunction with the throttle valve and the pneumatic regulating valve to ensure stable nitrogen delivery through the diversion pipe.

[0015] Preferably, one end of the diversion pipe connected to the backflush pipe of the adsorption tower is provided with a four-way valve.

[0016] A four-way valve was installed on the backflush pipe of the adsorption tower to connect the diversion pipe to the backflush pipe of the adsorption tower, without affecting the connection of the original pipeline of the backflush pipe of the adsorption tower.

[0017] Preferably, both the return pipe and the diversion pipe are structural components made of carbon steel.

[0018] Using carbon steel to make the reflux pipe and the distribution pipe can reduce costs, and the nitrogen pressure in the nitrogen pipeline network and the buffer tank is relatively low, which carbon steel meets.

[0019] Preferably, the end of the return pipe connected to the nitrogen pipeline network is provided with a branch pipe platform, and the return pipe is connected to the nitrogen pipeline network through the branch pipe platform.

[0020] During the pressure holding process, the nitrogen requirement is relatively small, as it is intended to replenish the nitrogen lost in the nitrogen buffer tank. Therefore, the diameter of the return pipe used to transport nitrogen should be relatively small, preferably within the range of DN10-DN30. However, the pipelines in the nitrogen pipeline network are usually DN200-DN500. Therefore, the return pipe can be installed by welding a branch pipe platform onto the nitrogen pipeline network, without the need for overall cutting or modification of the main pipe. This simplifies the construction and reduces the cost of modifying the nitrogen pipeline network.

[0021] Preferably, a three-way valve is provided at one end of the return pipe connected to the nitrogen buffer tank, and the three-way valve is used to connect to the drain pipe of the nitrogen buffer tank.

[0022] A three-way valve is installed at the end of the return pipe and attached to the drain pipe of the nitrogen buffer tank. The three-way valve controls the switching, thus achieving internal connection between the return pipe and the nitrogen buffer tank. During the return process, the drain is closed to prevent the return nitrogen from leaking through the drain pipe.

[0023] In a second aspect, the present invention provides a PSA nitrogen generator, comprising a purified air buffer tank, an adsorption tower A, an adsorption tower B and a nitrogen buffer tank connected in sequence, wherein an adsorption tower backflush pipeline connects the adsorption tower A and the adsorption tower B, and further comprising a pressure maintaining pipeline of the PSA nitrogen generator as described above.

[0024] This utility model discloses a PSA nitrogen generator. By connecting a return pipe to a buffer tank and connecting the return pipe to the nitrogen pipeline network, nitrogen can be introduced into the nitrogen buffer tank through the return pipe during the shutdown period of the nitrogen generator. This keeps the pressure inside the nitrogen buffer tank within a certain range, preventing a large amount of outside air from entering the buffer tank. When the device is restarted, it is not necessary to vent the buffer tank, thus improving the startup efficiency of the PSA nitrogen generator and ensuring the nitrogen supply to the nitrogen pipeline network.

[0025] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention provides a pressure-maintaining pipeline for a PSA nitrogen generator. During the shutdown period of the PSA nitrogen generator, the pressure of the nitrogen buffer tank is monitored in real time. When the pressure of the nitrogen buffer tank drops below the normal range, nitrogen is supplied to the nitrogen buffer tank through the return pipe to keep the internal pressure of the nitrogen buffer tank within the normal range. This prevents outside air from entering the nitrogen buffer tank. When the PSA nitrogen generator is restarted, it is not necessary to vent the nitrogen buffer tank, thereby improving the startup efficiency of the PSA nitrogen generator and ensuring the nitrogen supply to the nitrogen pipeline network. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the pressure-maintaining pipeline of a PSA nitrogen generator according to this utility model; Figure 2 This is a schematic diagram of the structure of a PSA nitrogen generator according to this utility model; Marked in the image: 1-Return pipe, 11-Pneumatic regulating valve, 12-Throttle valve, 13-First check valve, 14-Branch pipe platform, 15-Three-way valve, 2-PLC controller, 3-Pressure gauge, 4-Diverter pipe, 41-Second check valve, 42-Four-way valve, 5-Purified air buffer tank, 6-Adsorption tower A, 7-Adsorption tower B, 8-Nitrogen buffer tank, 9-Adsorption tower backflush pipe, 10-Nitrogen pipeline network. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to specific embodiments. However, it should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. All technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0028] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer" used in the description of specific embodiments of this utility model to indicate orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the utility model solution or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on this utility model.

[0029] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0030] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0031] Furthermore, in the description of the embodiments of this utility model, "several", "multiple", and "several" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0032] Furthermore, in the description of the technical solution of this utility model, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0033] Example 1 like Figure 1 and Figure 2As shown, a pressure-maintaining pipeline for a PSA nitrogen generator includes a return pipe 1, a PLC controller 2, and a pressure gauge 3. The pressure gauge 3 is installed on the nitrogen buffer tank 8 of the nitrogen generator, and the PLC controller 2 can be installed independently or integrated into the PLC control cabinet of the nitrogen generator. The return pipe 1 is made of 20# carbon steel with a diameter of DN10~DN30. It is equipped with a pneumatic regulating valve 11 to connect the nitrogen pipeline network 10 and the nitrogen buffer tank 8. The pipeline diameter of the nitrogen pipeline network 10 is DN200~DN500. A branch pipe platform 14 is installed on the pipeline of the nitrogen pipeline network 10. A three-way valve 15 is installed on the drain pipe of the nitrogen buffer tank 8. One end of the return pipe 1 is connected to the branch pipe platform 14 and the other end is connected to the three-way valve 15. The pressure gauge 3 is used to monitor the pressure of the nitrogen buffer tank 8; The pressure gauge 3 and the pneumatic regulating valve 11 are electrically connected to the PLC controller 2.

[0034] In this embodiment, a pressure-maintaining pipeline for a PSA nitrogen generator operates as follows: During the shutdown period of the PSA nitrogen generator, the pressure gauge 3 detects the nitrogen pressure inside the nitrogen buffer tank 8 and transmits the signal to the PLC controller 2. When the internal pressure of the nitrogen buffer tank 8 is lower than the normal range of 0.5~0.6 MPa, the PLC controller 2 controls the pneumatic regulating valve 11 to open, introducing nitrogen from the nitrogen pipeline network 10 into the nitrogen buffer tank 8 through the return pipe 1. When the internal pressure of the nitrogen buffer tank 8 is higher than the normal range of 0.5~0.6 MPa, the PLC controller 2 controls the pneumatic regulating valve 11 to close, thereby preventing the nitrogen pressure inside the nitrogen buffer tank 8 from becoming too high and thus increasing nitrogen loss. This maintains the internal pressure of the nitrogen buffer tank 8 within the range of 0.5~0.6 MPa, preventing outside air from entering the nitrogen buffer tank 8. When the PSA nitrogen generator is restarted, it is not necessary to vent the nitrogen buffer tank 8, improving the startup efficiency of the PSA nitrogen generator and ensuring the nitrogen supply to the nitrogen pipeline network 10.

[0035] In one or more embodiments, a throttle valve 12, a first check valve 13, and a diverter pipe 4 may also be provided on the return pipe 1.

[0036] Throttling valve 12: Located downstream of pneumatic regulating valve 11, its core function is to limit the maximum flow rate of returning nitrogen or provide a fixed resistance through mechanical flow restriction. Once set, the opening degree is fixed to prevent excessive flow when pneumatic regulating valve 11 fails. It can reduce the flow rate of high-pressure nitrogen and reduce the impact on the buffer tank.

[0037] The first one-way valve 13 is located downstream of the throttle valve 12. It can prevent nitrogen in the buffer tank from flowing back to the nitrogen pipeline 10, thus isolating pressure fluctuations, protecting the equipment in the return pipe 1 from reverse pressure, and maintaining system pressure stability. The one-way valve's zero reverse leakage characteristic can complement the flow restriction of the throttle valve 12 and the pressure regulation of the pneumatic regulating valve 11. The throttle valve 12 controls the upper limit of the forward flow, the pressure regulating valve stabilizes the downstream pressure, and the one-way valve ensures unidirectional flow and eliminates reverse interference.

[0038] Diverter pipe 4: Made of 20# carbon steel, it is located between the first one-way valve 13 and the throttle valve 12. A four-way valve 42 is installed on the backflush pipe 9 of the adsorption tower. The end of the diverter pipe 4 is connected to the four-way valve 42. Nitrogen from the nitrogen pipeline network 10 can be introduced into the adsorption towers A6 and B7 through the diverter pipe 4 to maintain the pressure of the adsorption towers and further reduce the venting time. A second one-way valve 41 is installed on the diverter pipe 4. The second one-way valve 41 has the same function as the first one-way valve 13. On the one hand, it prevents nitrogen from the adsorption tower from flowing back to the nitrogen pipeline network 10. On the other hand, it works in conjunction with the throttle valve 12 and the pneumatic regulating valve 11 to ensure stable nitrogen delivery through the diverter pipe 4.

[0039] Example 2 like Figure 1 and Figure 2 As shown, this embodiment provides a PSA nitrogen generator, including a purified air buffer tank 5, an adsorption tower A6, an adsorption tower B7, and a nitrogen buffer tank 8 connected in sequence. An adsorption tower backflush pipe 9 is connected between the adsorption tower A6 and the adsorption tower B7, and also includes a pressure-maintaining pipeline as described above for a PSA nitrogen generator.

[0040] In this embodiment, a PSA nitrogen generator is connected to a buffer tank via a return pipe 1, which is connected to a nitrogen pipeline network 10. During the shutdown of the nitrogen generator, nitrogen can be introduced into the nitrogen buffer tank 8 through the return pipe 1, so that the pressure inside the nitrogen buffer tank 8 is maintained within a certain range. This prevents a large amount of outside air from entering the buffer tank. When the device is restarted, it is not necessary to vent the buffer tank, which improves the startup efficiency of the PSA nitrogen generator and ensures the nitrogen supply to the nitrogen pipeline network 10.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A pressure-maintaining pipeline for a PSA nitrogen generator, characterized in that, It includes a return pipe (1), a PLC controller (2), and a pressure gauge (3). The return pipe (1) is equipped with a pneumatic regulating valve (11), and the return pipe (1) is used to connect the nitrogen pipeline (10) and the nitrogen buffer tank (8). The pressure gauge (3) is used to monitor the pressure of the nitrogen buffer tank (8); The pressure gauge (3) and the pneumatic regulating valve (11) are electrically connected to the PLC controller (2).

2. The pressure-maintaining pipeline for a PSA nitrogen generator according to claim 1, characterized in that, The return pipe (1) is also provided with a throttle valve (12), which is located downstream of the pneumatic regulating valve (11).

3. The pressure-maintaining pipeline for a PSA nitrogen generator according to claim 2, characterized in that, The return pipe (1) is also provided with a first check valve (13), which is located downstream of the throttle valve (12).

4. The pressure-maintaining pipeline for a PSA nitrogen generator according to claim 3, characterized in that, The return pipe (1) is also provided with a diversion pipe (4), which is used to connect the adsorption tower backflush pipe (9). The diversion pipe (4) is connected between the first one-way valve (13) and the throttle valve (12).

5. The pressure-maintaining pipeline for a PSA nitrogen generator according to claim 4, characterized in that, The diversion pipe (4) is equipped with a second one-way valve (41).

6. The pressure-maintaining pipeline for a PSA nitrogen generator according to claim 4, characterized in that, The diversion pipe (4) is connected to the backflush pipe (9) of the adsorption tower at one end and is provided with a four-way valve (42). The four-way valve (42) is used to connect to the backflush pipe (9) of the adsorption tower.

7. The pressure-maintaining pipeline for a PSA nitrogen generator according to claim 3, characterized in that, Both the return pipe (1) and the diversion pipe (4) are structural components made of carbon steel.

8. A pressure-maintaining pipeline for a PSA nitrogen generator according to any one of claims 1-7, characterized in that, The return pipe (1) is connected to the nitrogen pipeline network (10) at one end and is provided with a branch pipe platform (14). The return pipe (1) is connected to the nitrogen pipeline network (10) through the branch pipe platform (14).

9. A pressure-maintaining pipeline for a PSA nitrogen generator according to any one of claims 1-7, characterized in that, The return pipe (1) is connected to the nitrogen buffer tank (8) at one end and is equipped with a three-way valve (15). The three-way valve (15) is used to connect to the drain pipe of the nitrogen buffer tank (8).

10. A PSA nitrogen generator, comprising a purified air buffer tank (5), an adsorption tower A (6), an adsorption tower B (7), and a nitrogen buffer tank (8) connected in sequence, wherein an adsorption tower A (6) and an adsorption tower B (7) are connected by an adsorption tower backflush pipe (9), characterized in that, It also includes a pressure-maintaining pipeline for a PSA nitrogen generator as described in any one of claims 1-9.

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