Intelligent efficient helium recovery and purification all-in-one machine
Through the design of the intelligent and efficient helium recovery and purification integrated machine, the automatic purification and replenishment of helium is achieved by using the gas pressure difference, solving the problems of low helium recovery efficiency and high cost in traditional technology, and improving the helium recovery rate and stable supply sex.
Patent Information
- Application Number
- CN202420926127.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-04-30
AI Technical Summary
In traditional pressure-switch adsorption tower technology, helium is adsorbed by filling the sub-sieve or carbon powder in the tower, and the helium recovery efficiency is low, and the adsorbent material is easy to powder, resulting in high recycling costs and low recovery rates.
Design an intelligent and efficient helium recovery and purification integrated machine, through the cooperation of the shell, recycling port, buffer tank, compressor, storage tank, purifier, concentration meter and controller, to realize automatic gas delivery pipeline by using the gas pressure difference Control, carry out automatic purification, online monitoring and automatic replenishment of helium, reduce the volume of the equipment, and accurately control the purification concentration according to the use needs.
It improves helium recovery rate, reduces equipment maintenance frequency and maintenance costs, ensures a stable supply of high-purity helium, and reduces helium recovery costs.
Smart Images
Figure CN222239513U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of helium recovery and purification equipment, in particular to an intelligent and efficient helium recovery and purification integrated machine. Background Art
[0002] Helium recovery and purification equipment is a device that can recover and purify helium. It is mainly used to collect and purify low-concentration helium emitted from the helium detection process. The helium purification equipment can purify the waste helium emitted by the helium detection recovery system online and circulate it to the low-pressure tank for recycling, thereby reducing helium consumption and reducing costs for users. In the prior art, the traditional pressure swing adsorption tower technology for recovering and purifying helium adsorbs helium by filling the tower with materials such as molecular sieves or carbon powder. The helium recovery efficiency is low, and the adsorption material is easy to pulverize and needs to be replaced frequently, resulting in high helium recovery costs and low recovery rates. Utility Model Content
[0003] In view of the shortcomings of the prior art, the utility model provides an intelligent and efficient helium recovery and purification integrated machine, which solves the problems in the prior art that the traditional pressure swing adsorption tower technology for recovering and purifying helium adsorbs helium by filling molecular sieves or carbon powder and other materials in the tower, the helium recovery efficiency is low, and the adsorption material is easy to pulverize and needs to be replaced frequently, resulting in high helium recovery costs and low recovery rates.
[0004] To achieve the above-mentioned purpose, the utility model is implemented through the following technical solutions: an intelligent and efficient helium recovery and purification integrated machine, comprising a shell, a recovery port is provided on one side of the shell, the recovery port is connected to a buffer tank, the output end of the buffer tank is connected to a compressor, the output end of the compressor is connected to a storage tank, the output end of the storage tank is connected to a gas supply port, the output end of the storage tank is connected to a purifier, an exhaust gas outlet is provided on one side of the purifier, the top of the purifier is connected to a concentration meter, a helium source port is provided on one side of the shell, the concentration meter and the helium source port are both connected to the buffer tank, and a controller is provided inside the shell, and the controller is electrically connected to the compressor and the concentration meter, respectively.
[0005] Preferably, the output end of the compressor is connected to a first solenoid valve, the output end of the purifier is connected to a second solenoid valve, the first solenoid valve and the second solenoid valve are both connected to a concentration meter, the input end of the purifier is connected to a third solenoid valve, the third solenoid valve is connected to the output end of a storage tank, the inner wall of the helium source port is connected to a fourth solenoid valve, the fourth solenoid valve is connected to a buffer tank, and the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are all electrically connected to a controller.
[0006] Preferably, the inner wall of the recovery port is connected to a fifth solenoid valve, the output end of the fifth solenoid valve is connected to a recovery tank, the output end of the recovery tank is connected to a vacuum pump, the output end of the vacuum pump is connected to a buffer tank, and the fifth solenoid valve and the vacuum pump are both electrically connected to the controller.
[0007] Preferably, an inlet flow meter is installed on a side of the third solenoid valve close to the purifier, and an outlet flow meter is installed on a side of the purifier close to the second solenoid valve, and both the inlet flow meter and the outlet flow meter are electrically connected to the controller.
[0008] Preferably, a gas pressure transmitter is installed on the top of the buffer tank and the storage tank, the input end of the compressor is connected to the sixth solenoid valve, the sixth solenoid valve is connected to the output end of the buffer tank, the output end of the compressor is connected to the seventh solenoid valve, the seventh solenoid valve is connected to the output end of the buffer tank, and the gas pressure transmitter, the sixth solenoid valve and the seventh solenoid valve are all electrically connected to the controller.
[0009] The utility model provides an intelligent and efficient helium recovery and purification integrated machine. It has the following beneficial effects: the intelligent and efficient helium recovery and purification integrated machine, through the coordination between the shell, recovery port, buffer tank, compressor, storage tank, gas supply port, purifier, waste gas outlet, concentration meter, helium source port and controller, automatically controls the valve of the recovery gas transmission pipeline, utilizes the gas pressure difference between the buffer tank and the storage tank, enables the recovery gas to be transported according to the set transmission route, and realizes automatic purification of the recovery gas, online monitoring of helium concentration and automatic replenishment of helium during the transportation process, and compared with the traditional pressure swing adsorption tower technology, it can reduce the volume of the equipment, and at the same time can more accurately control the helium purification concentration according to the use requirements, improve the recovery rate of helium, and reduce the maintenance frequency and maintenance cost of the equipment, which helps enterprises reduce the cost of helium recovery.
[0010] Through the cooperation among the buffer tank, the compressor, the storage tank, the purifier, the concentration meter, the helium source port, the controller, the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve, the control system can adjust and control the transport pipeline of the recovered gas, thereby ensuring that the gas can correctly enter the corresponding processing device, so that the equipment can automatically detect the helium concentration of the recovered gas, and automatically purify the recovered gas according to the concentration setting requirements. At the same time, when the pressure reaches the set alarm point, the fourth solenoid valve is automatically opened to supplement the helium, so that the equipment has the functions of automatic purification, automatic circulation and automatic supplementation, and the automation rate of the equipment is improved, so as to ensure the stability and continuity of the supply of high-purity helium. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a schematic diagram of the structure of the utility model;
[0012] Figure 2 for Figure 1 A partial enlarged view of the middle A area;
[0013] Figure 3 It is the principle diagram of the utility model.
[0014] In the figure: 1. shell, 2. recovery port, 3. buffer tank, 4. compressor, 5. storage tank, 6. gas supply port, 7. purifier, 8. exhaust gas outlet, 9. concentration meter, 10. helium source port, 11. controller, 12. first solenoid valve, 13. second solenoid valve, 14. third solenoid valve, 15. fourth solenoid valve, 16. fifth solenoid valve, 17. recovery tank, 18. vacuum pump, 19. inlet flow meter, 20. outlet flow meter, 21. gas pressure transmitter, 22. sixth solenoid valve, 23. seventh solenoid valve. DETAILED DESCRIPTION
[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0016] In the prior art, the conventional pressure swing adsorption tower technology performs adsorption by filling the tower with materials such as molecular sieves or carbon powder. The adsorption material needs to be replaced frequently and is easily pulverized, resulting in high helium recovery costs and low recovery rates.
[0017] In view of this, the utility model provides an intelligent and efficient helium recovery and purification integrated machine, which cooperates with a shell, a recovery port, a buffer tank, a compressor, a storage tank, a gas supply port, a purifier, an exhaust gas outlet, a concentration meter, a helium source port and a controller, and automatically controls the valve of the recovery gas transmission pipeline. By utilizing the gas pressure difference between the buffer tank and the storage tank, the recovered gas can be transported according to the set transmission route, and during the transportation process, the recovered gas can be automatically purified, the helium concentration can be monitored online, and the helium can be automatically replenished, thereby ensuring a stable supply of high-purity helium. Compared with the traditional pressure swing adsorption tower technology, the volume of the equipment is reduced, and the helium purification concentration can be more accurately controlled according to the use requirements, thereby improving the helium recovery rate, reducing the maintenance frequency and maintenance cost of the equipment, and thus reducing the helium recovery cost.
[0018] Through the personnel in this field, all the electrical components in this case are connected to their corresponding power supplies through wires, and appropriate controllers and encoders should be selected according to actual conditions to meet the control requirements. The specific connection and control sequence should refer to the following working principle, and the electrical connection between the electrical components is completed in the order of working in sequence. The detailed connection means are well-known technologies in this field. The following mainly introduces the working principles and processes, and no longer explains the electrical control.
[0019] Depend on Figure 1-3 It can be seen that an intelligent and efficient helium recovery and purification integrated machine includes a shell 1, which is the body shell of the helium recovery and purification integrated machine. A recovery port 2 is provided on one side of the shell 1, and the recovery port 2 is connected to the delivery pipeline of the recovered gas to realize the input of the recovered gas into the helium recovery and purification integrated machine. The recovery port 2 is connected to a buffer tank 3, and the output end of the buffer tank 3 is connected to a compressor 4, and the output end of the compressor 4 is connected to a storage tank 5, and the output end of the storage tank 5 is connected to a gas supply port 6, which is used to output the recovered and purified helium. The output end of the storage tank 5 is connected to a purifier 7, and one side of the purifier 7 is provided with an exhaust gas outlet 8, and the top of the purifier 7 is connected with a concentration meter 9, and one side of the shell 1 is provided with a helium source port 10, and the concentration meter 9 and the helium source port 10 are both connected to the buffer tank 3. A controller 11 is provided inside the shell 1, and the controller 11 is electrically connected to the compressor 4 and the concentration meter 9 respectively;
[0020] In the specific implementation process, it is worth pointing out that the shell 1 is the body shell of the helium recovery and purification integrated machine, and the recovery port 2 is connected to the recovery gas delivery pipeline to realize the input of the recovered gas into the helium recovery and purification integrated machine. Through the cooperation between the shell 1, the recovery port 2 and the buffer tank 3, a gas delivery device is provided between the recovery port 2 and the buffer tank 3 to realize the delivery of the recovered gas from the recovery port 2 to the buffer tank 3. Through the cooperation between the buffer tank 3, the compressor 4 and the storage tank 5, the delivery of the recovered gas from the buffer tank 3 to the storage tank 5 is realized, and the recovered gas is compressed by the compressor 4, so that there is a certain pressure difference between the recovered gas in the buffer tank 3 and the storage tank 5, so as to ensure the stable delivery of the recovered gas in each pipeline, and then The recovered gas is subjected to concentration detection and purification operations, and the gas supply port 6 is used to output the recovered and purified helium. Through the cooperation among the buffer tank 3, the compressor 4, the storage tank 5, the purifier 7, the waste gas outlet 8 and the concentration meter 9, since there is a certain pressure difference between the gas in the buffer tank 3 and the storage tank 5, when the recovered gas needs to be purified, the controller 11 automatically adjusts the delivery pipeline of the recovered gas, so that the recovered gas in the storage tank 5 is delivered to the purifier 7 for purification, and the purified gas is delivered to the buffer tank 3 with lower gas pressure, and the helium concentration is detected by the concentration meter 9 during the delivery process, and the waste gas generated is discharged through the waste gas outlet 8. By continuously delivering the recovered gas, the helium concentration of the recovered gas is increased. The degree is increased to a set value, the efficiency of helium purification is improved, and automatic purification and automatic circulation of helium are realized. Through the cooperation between the buffer tank 3 and the helium source port 10, as the helium concentration in the recovered gas increases, the exhausted waste gas causes gas loss. By controlling the valve of the helium source port 10 to switch, high-purity helium can be replenished in the buffer tank 3 to ensure the stability and continuity of the helium supply. The controller 11 is connected to a control panel for controlling the electrical components of the helium recovery and purification machine and collecting measurement signals. Through the shell 1, the recovery port 2, the buffer tank 3, the compressor 4, the storage tank 5, the gas supply port 6, the purifier 7, the waste gas outlet 8, the concentration meter 9, the helium source port 10 and the controller 11 By automatically controlling the valve of the recovered gas delivery pipeline and utilizing the gas pressure difference between the buffer tank 3 and the storage tank 5, the recovered gas can be delivered according to the set delivery route, and in the delivery process, the recovered gas can be automatically purified, the helium concentration can be monitored online, and the helium can be automatically replenished, thereby ensuring a stable supply of high-purity helium. Compared with the traditional pressure swing adsorption tower technology, the volume of the equipment is reduced, and the helium purification concentration can be more accurately controlled according to the use requirements, thereby improving the helium recovery rate, reducing the maintenance frequency and maintenance cost of the equipment, and thus reducing the helium recovery cost. The specific models of the compressor 4, the purifier 7, the concentration meter 9 and the controller 11 are not limited, and only need to meet the use requirements;
[0021] Further, the output end of the compressor 4 is connected to the first solenoid valve 12, the output end of the purifier 7 is connected to the second solenoid valve 13, the first solenoid valve 12 and the second solenoid valve 13 are both connected to the concentration meter 9, the input end of the purifier 7 is connected to the third solenoid valve 14, the third solenoid valve 14 is connected to the output end of the storage tank 5, the inner wall of the helium source port 10 is connected to the fourth solenoid valve 15, the fourth solenoid valve 15 is connected to the buffer tank 3, and the first solenoid valve 12, the second solenoid valve 13, the third solenoid valve 14 and the fourth solenoid valve 15 are all electrically connected to the controller 11;
[0022] In the specific implementation process, it is worth pointing out that, through the cooperation between the buffer tank 3, the compressor 4, the concentration meter 9, the controller 11, the first solenoid valve 12 and the second solenoid valve 13, when it is necessary to detect the helium concentration of the recovered gas, the controller 11 automatically opens the first solenoid valve 12 and closes the second solenoid valve 13, stops the delivery of the purified gas to the concentration meter 9, and allows the gas output by the compressor 4 to be delivered to the concentration meter 9, and then flows back to the buffer tank 3 from the concentration meter 9. The concentration meter 9 detects the helium concentration during the recovery gas delivery process and transmits the detection data in real time. The controller 11 is used to detect the helium concentration in the recovered gas. Through the cooperation among the purifier 7, the controller 11, the second solenoid valve 13 and the third solenoid valve 14, when the recovered gas needs to be purified, the controller 11 automatically opens the second solenoid valve 13 and the third solenoid valve 14 to control the delivery of the recovered gas from the storage tank 5 to the purifier 7, and after the purification is completed, it is delivered to the concentration meter 9 for concentration detection, and then the concentration meter 9 returns to the buffer tank 3. Through the cooperation among the buffer tank 3, the helium source port 10, the controller 11 and the fourth solenoid valve 15, when it is needed, When replenishing helium, the controller 11 automatically controls the fourth solenoid valve 15 to open or close the gas replenishment pipeline to realize the replenishment of helium to the buffer tank 3. Through the cooperation among the buffer tank 3, the compressor 4, the storage tank 5, the purifier 7, the concentration meter 9, the helium source port 10, the controller 11, the first solenoid valve 12, the second solenoid valve 13, the third solenoid valve 14 and the fourth solenoid valve 15, the controller 11 automatically controls the first solenoid valve 12, the second solenoid valve 13, the third solenoid valve 14 and the fourth solenoid valve 15 to realize the regulation and control of the transport pipeline of the recovered gas. , ensuring that the gas can correctly enter the corresponding processing device, so that the equipment can automatically detect the helium concentration of the recovered gas, and automatically purify the recovered gas according to the concentration setting requirements, and when the pressure reaches the set alarm point, the fourth solenoid valve 15 is automatically opened to replenish the helium, so that the equipment has the functions of automatic purification, automatic circulation and automatic replenishment, ensuring the stability and continuity of the high-purity helium supply, wherein the specific models of the first solenoid valve 12, the second solenoid valve 13, the third solenoid valve 14 and the fourth solenoid valve 15 are not limited, and can meet the use requirements;
[0023] Further, the inner wall of the recovery port 2 is connected with a fifth solenoid valve 16, which can control the input of the recovered gas, and the output end of the fifth solenoid valve 16 is connected with a recovery tank 17, which is used to store the recovered gas. At the same time, when the negative pressure generated by the vacuum pump 18 is too high, it can play a certain buffering role to reduce the impact of the negative pressure on the pipeline. The output end of the recovery tank 17 is connected with the vacuum pump 18, and the output end of the vacuum pump 18 is connected to the buffer tank 3. The fifth solenoid valve 16 and the vacuum pump 18 are both electrically connected to the controller 11;
[0024] In the specific implementation process, it is worth pointing out that the fifth solenoid valve 16 can control the input of the recovered gas, and the recovery tank 17 is used to store the recovered gas. At the same time, when the negative pressure generated by the vacuum pump 18 is too high, it can play a certain buffering role to reduce the impact of the negative pressure on the pipeline. Through the cooperation between the recovery port 2, the controller 11, the fifth solenoid valve 16, the recovery tank 17 and the vacuum pump 18, by arranging the recovery tank 17 and the vacuum pump 18 at the input end of the buffer tank 3, the pressurized input of the recovered gas to the buffer tank 3 is realized, and the recovery tank 17 is used to store the recovered gas, and the fifth solenoid valve 16 controls the switch of the recovery port 2 to avoid the negative pressure generated by the vacuum pump 18 from affecting the recovered gas delivery pipeline, thereby ensuring the normal operation of the pipeline and the safe delivery of the recovered gas. The specific models of the fifth solenoid valve 16 and the vacuum pump 18 are not limited, and they can meet the use requirements;
[0025] Furthermore, an inlet flow meter 19 is installed on the side of the third solenoid valve 14 close to the purifier 7, and an outlet flow meter 20 is installed on the side of the purifier 7 close to the second solenoid valve 13. Both the inlet flow meter 19 and the outlet flow meter 20 are electrically connected to the controller 11;
[0026] In the specific implementation process, it is worth pointing out that, through the coordination between the purifier 7, the controller 11, the inlet flow meter 19 and the outlet flow meter 20, by measuring the gas flow at the input and output ends of the purifier 7, and transmitting the measurement signal to the controller 11 in real time, the working efficiency of the purifier 7 and the purification status in the helium recovery and purification process can be more accurately understood, and important reference data can be provided for the subsequent automatic helium replenishment, wherein the specific models of the inlet flow meter 19 and the outlet flow meter 20 are not limited, and can meet the use requirements;
[0027] Furthermore, a gas pressure transmitter 21 is installed on the top of the buffer tank 3 and the storage tank 5. The gas pressure transmitter 21 is used to measure the gas pressure in the buffer tank 3 and the storage tank 5, and transmit the measurement signal to the controller 11 in real time, so as to facilitate the helium recovery and purification system to control the helium transmission. The input end of the compressor 4 is connected with a sixth solenoid valve 22, which is connected with the output end of the buffer tank 3. The output end of the compressor 4 is connected with a seventh solenoid valve 23, which is connected with the output end of the buffer tank 3. The gas pressure transmitter 21, the sixth solenoid valve 22 and the seventh solenoid valve 23 are all electrically connected to the controller 11.
[0028] During the specific implementation process, it is worth pointing out that the gas pressure transmitter 21 is used to measure the gas pressure in the buffer tank 3 and the storage tank 5, and transmit the measurement signal to the controller 11 in real time, so as to facilitate the helium recovery and purification system to control the pressure difference between the buffer tank 3 and the storage tank 5, and ensure the stability of gas transportation between the pipelines. Through the cooperation between the buffer tank 3, the compressor 4, the storage tank 5, the controller 11, the gas pressure transmitter 21, the sixth solenoid valve 22 and the seventh solenoid valve 23, when the gas pressure in the storage tank 5 is too high and reaches a certain value, the controller 11 opens the seventh solenoid valve 23 to reduce the gas input to the storage tank 5, and adjusts the pressure difference between the buffer tank 3 and the storage tank 5 to avoid frequent startup of the boosting device, extend the maintenance cycle of the compressor 4, improve the service life, and achieve the purpose of energy saving and cost reduction. The specific models of the gas pressure transmitter 21, the sixth solenoid valve 22 and the seventh solenoid valve 23 are not limited, and they can meet the use requirements.
[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".
[0030] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated 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 the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.
[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. An intelligent and efficient helium recovery and purification integrated machine, comprising a housing (1), characterized in that: A recovery port (2) is provided on one side of the shell (1), the recovery port (2) is connected to a buffer tank (3), the output end of the buffer tank (3) is connected to a compressor (4), the output end of the compressor (4) is connected to a storage tank (5), the output end of the storage tank (5) is connected to a gas supply port (6), the output end of the storage tank (5) is connected to a purifier (7), a waste gas outlet (8) is provided on one side of the purifier (7), the top of the purifier (7) is connected to a concentration meter (9), a helium source port (10) is provided on one side of the shell (1), the concentration meter (9) and the helium source port (10) are both connected to the buffer tank (3), a controller (11) is provided inside the shell (1), and the controller (11) is electrically connected to the compressor (4) and the concentration meter (9), respectively.
2. According to claim 1, an intelligent and efficient helium recovery and purification integrated machine is characterized in that: The output end of the compressor (4) is connected to a first solenoid valve (12), the output end of the purifier (7) is connected to a second solenoid valve (13), the first solenoid valve (12) and the second solenoid valve (13) are both connected to a concentration meter (9), the input end of the purifier (7) is connected to a third solenoid valve (14), the third solenoid valve (14) is connected to the output end of the storage tank (5), the inner wall of the helium source port (10) is connected to a fourth solenoid valve (15), the fourth solenoid valve (15) is connected to the buffer tank (3), and the first solenoid valve (12), the second solenoid valve (13), the third solenoid valve (14) and the fourth solenoid valve (15) are all electrically connected to a controller (11).
3. The intelligent and efficient helium recovery and purification integrated machine according to claim 1 is characterized in that: The inner wall of the recovery port (2) is connected to a fifth solenoid valve (16), the output end of the fifth solenoid valve (16) is connected to a recovery tank (17), the output end of the recovery tank (17) is connected to a vacuum pump (18), the output end of the vacuum pump (18) is connected to the buffer tank (3), and the fifth solenoid valve (16) and the vacuum pump (18) are both electrically connected to the controller (11).
4. The intelligent and efficient helium recovery and purification integrated machine according to claim 2, characterized in that: An inlet flow meter (19) is installed on the side of the third solenoid valve (14) close to the purifier (7), and an outlet flow meter (20) is installed on the side of the purifier (7) close to the second solenoid valve (13). Both the inlet flow meter (19) and the outlet flow meter (20) are electrically connected to the controller (11).
5. The intelligent and efficient helium recovery and purification integrated machine according to claim 1, characterized in that: A gas pressure transmitter (21) is installed on the top of the buffer tank (3) and the storage tank (5); the input end of the compressor (4) is connected to a sixth solenoid valve (22), and the sixth solenoid valve (22) is connected to the output end of the buffer tank (3); the output end of the compressor (4) is connected to a seventh solenoid valve (23), and the seventh solenoid valve (23) is connected to the output end of the buffer tank (3); the gas pressure transmitter (21), the sixth solenoid valve (22) and the seventh solenoid valve (23) are all electrically connected to the controller (11).