A vacuum air extraction device
By setting up multiple pipelines and regulating valves in the vacuum pumping device, combined with a PID controller, precise control of the vacuum pressure change rate in a large vacuum system was achieved, solving the problem of unstable vacuum pressure change rate in the vacuum system and achieving a control accuracy of less than 1 Pa/s.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ANHUI CHUANGPU INSTR TECH CO LTD
- Filing Date
- 2025-07-30
- Publication Date
- 2026-07-14
AI Technical Summary
Existing technologies struggle to achieve precise control of the rate of change of vacuum pressure in large vacuum systems, especially as sudden pressure changes can easily occur when valves are opened.
A vacuum pumping device was designed. By setting multiple regulating valves and control units on multiple pipelines, and using a combination of pneumatic and electric valves, combined with a PID controller, the vacuum pressure in the vacuum chamber can be precisely regulated. The device includes a first pipeline, a second pipeline, and a third pipeline. The opening and closing degree of regulating valves such as pneumatic slide gate valves, pneumatic angle valves, and electric angle valves are controlled, and dynamic regulation is performed in conjunction with a PLC and a host computer.
It achieves precise control of the rate of change of vacuum pressure within the vacuum chamber, reaching an accuracy of less than 1 Pa/s, thus solving the problem of unstable rate of change of vacuum pressure in large vacuum systems.
Smart Images
Figure CN224498210U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of vacuum equipment technology, and specifically relates to a vacuum pumping device. Background Technology
[0002] In the field of accelerators and beamlines, experimental stations containing optical films are usually required to have a vacuum pressure change rate of less than a certain value in order to reduce the impact on the pressure difference across the optical film. For example, a filter film (0.2 μm thick) requires a vacuum pressure change rate of less than 300 Pa / s. Since the pumping speed is constant, the vacuum pressure change rate is usually adjusted by controlling the flow conductance between the pump and the vacuum system.
[0003] In existing technical solutions, for small vacuum systems, a flow meter regulation scheme is used. The advantage of this scheme is that the flow conductance is adjustable, but the disadvantage is that the upper limit of the flow conductance is relatively low, making it unsuitable for large vacuum systems. For large vacuum systems, a multi-stage fixed flow conductance switching method is used to control the rate of change of vacuum pressure. The advantage of this scheme is that the flow conductance can reach the theoretical maximum value. However, such devices are limited by the number of flow conductances in the design, and sudden changes in gas pressure within the vacuum system are prone to occur at the moment the valve is opened. Utility Model Content
[0004] The purpose of this invention is to provide a vacuum pumping device to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a vacuum pumping device, comprising:
[0006] The first pipeline has one end connected to the pump body and the other end connected to the vacuum chamber. The first pipeline is provided with a first regulating valve and a molecular pump in sequence along the gas flow direction. The first pipeline has a first diversion point between the pump body and the molecular pump.
[0007] The second pipeline includes a parallel flow section, a first branch section, and a second branch section. The parallel flow section is provided with a third regulating valve and has a first end connected to a first diversion point and a second end located away from the first end. The parallel flow section is provided with a second diversion point between the third regulating valve and the second end. One end of the first branch section and the second branch section are both connected to the second end of the parallel flow section, and the other end of both are connected to a vacuum chamber. The first branch section is provided with a fourth regulating valve, and the second branch section is provided with a fifth regulating valve.
[0008] The third pipeline is connected at one end to an external nitrogen cylinder and at the other end to the second branch point, and a proportional valve is installed on the third pipeline.
[0009] Furthermore, a second regulating valve is also provided on the first pipeline, which is located between the molecular pump and the first split point.
[0010] Furthermore, a sixth regulating valve is also provided on the third pipeline, which is located between the proportional valve and the second diversion point.
[0011] Furthermore, the first regulating valve, the second regulating valve, the third regulating valve, and the sixth regulating valve are all pneumatic valves.
[0012] Furthermore, the first regulating valve is a pneumatic slide gate valve, and the second, third, and sixth regulating valves are all pneumatic angle valves.
[0013] Furthermore, the third, fourth, and fifth regulating valves are all electric valves.
[0014] Furthermore, both the third and fifth regulating valves are configured as electric angle valves including a stepper motor and a reducer.
[0015] Furthermore, the fourth regulating valve is an electric fine-tuning valve controlled by a stepper motor.
[0016] Furthermore, the vacuum pumping device also includes a gauge tube and a control unit that is communicatively connected to the gauge tube. The control unit is configured to control the opening and closing degree of the valves on the first pipeline, the second pipeline and the third pipeline based on the vacuum value data read by the gauge tube in the vacuum chamber.
[0017] Furthermore, the control unit includes a host computer and a PLC connected via communication.
[0018] Compared with the prior art, the beneficial effects of this utility model are:
[0019] This application provides a control pipeline design for the vacuum chamber, including a first pipeline, a second pipeline, and a third pipeline. A regulating valve is installed on each pipeline. By controlling the opening and closing of the regulating valves on different pipelines, the stepless adjustment of the large conductance can be achieved, ensuring precise control of the vacuum pressure inside the vacuum chamber. Attached Figure Description
[0020] Figure 1 Schematic diagram of a vacuum pumping device Figure 1 ;
[0021] Figure 2 Schematic diagram of a vacuum pumping device Figure 2 .
[0022] In the picture:
[0023] 10. First pipeline; 10a. First branch point; 101. First regulating valve; 102. Molecular pump; 103. Second regulating valve; 105. Pump body;
[0024] 20. Second pipeline; 21. Parallel flow section; 21a. Second branch point; 210. Third regulating valve; 22. First branch section; 220. Fourth regulating valve; 23. Second branch section; 230. Fifth regulating valve;
[0025] 30. Third pipeline; 300. Proportional valve; 301. Sixth regulating valve;
[0026] 40. Regulation. Detailed Implementation
[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0028] A vacuum pumping device, as described above Figure 1 The main body consists of a first pipeline 10, a second pipeline 20, and a third pipeline 30. One end of the first pipeline 10 is connected to a pump body 105 (e.g., a vortex dry pump), and the other end is connected to a vacuum chamber. A first regulating valve 101 and a molecular pump 102 are sequentially arranged in the first pipeline 10 along the gas flow direction. A first diversion point 10a is provided between the pump body 105 and the molecular pump 102 in the first pipeline 10. This first diversion point 10a serves as the connection point between the first pipeline 10 and the second pipeline 20. Specifically, the main body of the second pipeline consists of a parallel flow section 21, a first branch section 22, and a second branch section 23. A third regulating valve 210 is provided on the parallel flow section 21, which has a first end connected to the first diversion point 10a and a second end located away from the first end. A second diversion point 21a is provided between the third regulating valve 210 and the second end in the parallel flow section 21. This second diversion point 21a serves as the connection point between the second pipeline 20 and the third pipeline 30. (Continuing to refer to...) Figure 1 The configuration of the second pipeline 20 is described below. One end of the first branch section 22 and the second branch section 23 are both connected to the second end of the parallel flow section 21, and the other end is both connected to the vacuum chamber. The first branch section 22 is provided with a fourth regulating valve 220, and the second branch section 23 is provided with a fifth regulating valve 230. That is, the first pipeline 10, the parallel flow section 21 and the first branch section 22, as well as the parallel flow section 21 and the second branch section 23, are all configured as connecting pipelines between the pump body 105 and the vacuum chamber.
[0029] Continue to refer to Figure 1 One end of the aforementioned third pipeline 30 is connected to an external nitrogen cylinder (with a pressure reducing valve and a filter), and the other end is connected to the second branch point 21a. A proportional valve 300 is provided on the third pipeline 30.
[0030] In some embodiments, the first pipeline 10 is further provided with a second regulating valve 103, which is disposed between the molecular pump 102 and the first diversion point 10a.
[0031] In some embodiments, the third pipeline 30 is further provided with a sixth regulating valve 301, which is disposed between the proportional valve 300 and the second diversion point 21a.
[0032] In some embodiments, the first regulating valve 101, the second regulating valve 103, the third regulating valve 210 and the sixth regulating valve 301 are all pneumatic valves. For example, the first regulating valve 101 is a pneumatic slide gate valve, and the second regulating valve 103, the third regulating valve 210 and the sixth regulating valve 301 are all pneumatic angle valves.
[0033] In some embodiments, the third regulating valve 210, the fourth regulating valve 220, and the fifth regulating valve 230 are all electric valves. For example, the third regulating valve 210 and the fifth regulating valve 230 are both configured as electric angle valves including a stepper motor and a reducer, and the fourth regulating valve 220 is configured as an electric fine-tuning valve controlled by a stepper motor. By applying the stepper motor to the vacuum angle valve and the fine-tuning valve, the opening and closing degree of the vacuum angle valve and the fine-tuning valve can be electrically adjusted, thereby achieving stepless adjustment of large flow conductance. With the subsequent PID control by the host computer, the control accuracy of the vacuum pressure change rate is less than 1 Pa / s.
[0034] In some embodiments, refer to Figure 2 The aforementioned vacuum pumping device also includes a control unit and a gauge 40 (full-range gauge 40) communicatively connected to the control unit. The control unit reads the vacuum value inside the vacuum chamber through the gauge 40 to obtain the actual rate of change of the vacuum level inside the vacuum chamber. It then compares this rate of change with a pre-set rate of change to obtain the deviation. This deviation is used as input, and a PID controller calculates the control quantity, thereby adjusting the opening and closing degrees of the valves on the first pipeline 10, the second pipeline 20, and the third pipeline 30 to ensure that the control accuracy of the vacuum pressure change rate is less than 1 Pa / s. For example, the control unit includes a programmable logic controller (PLC) connected to the PLC. The controller (PLC) and host computer, corresponding to the control valve body configuration of the electric angle valve and electric fine-tuning valve mentioned above, at this time, the host computer establishes communication with the full-range gauge tube 40 through the PLC, reads the vacuum value in the vacuum chamber, and can obtain the actual rate of change of the vacuum degree in the vacuum chamber. Then, it is compared with the pre-set rate of change to obtain the deviation. The deviation is used as input, and the PID controller calculates the control quantity. The PLC outputs the control quantity to the stepper motor driver. The motor driver outputs pulses to control the stepper motor to rotate, thereby adjusting the opening and closing degree of the vacuum angle valve and needle valve, and finally achieving a control accuracy of less than 1 Pa / s for the vacuum pressure change rate.
[0035] Based on the above pipeline design, the rate of pressure change within the vacuum chamber can be dynamically adjusted by controlling the pipeline conductance. The control range is mainly (1E1~1E5Pa). The conductance is related to the pipeline size and the gas pressure at both ends of the pipeline. The specific formula is as follows:
[0036]
[0037] U n.20 —The flow conductance of the pipe to 20°C air, in meters. 3 / s;
[0038] d—Pipe diameter, in meters;
[0039] L—Pipe length, in meters;
[0040] p1, p2 — Gas pressure at both ends of the pipe, in Pa.
[0041] For example, when vacuuming is first started, the vacuum pressure in the vacuum chamber is 1E5Pa, which is atmospheric. After the pump (e.g., a mechanical pump) starts, the vacuum pressure at the pump outlet is 1Pa. Compared with the pressure in the vacuum chamber, the change range of the vacuum pressure at the pump outlet is negligible. Through high-precision control of the flow conduction in the pipeline, the flow conduction in the pipeline can be infinitely adjustable, thereby enabling the vacuum pressure in the vacuum chamber to change according to the required rate of decrease. Based on the above principle explanation and the attached diagram of the vacuum pumping device, the slow pumping and slow breaking process of the above vacuum pumping device will be explained.
[0042] The slow extraction process is as follows:
[0043] 1. Start pump body 105;
[0044] 2. Open the second regulating valve 103 and the third regulating valve 210;
[0045] 3. Slowly open the fourth regulating valve 220 (fine-tuning valve), and perform PID control on the opening degree based on the difference between the preset rate of change and the actual rate of change;
[0046] 4. The vacuum level inside the vacuum chamber is less than 1E4 (1*10). 4 (The same applies to subsequent operations) When Pa is reached, the fifth regulating valve 230 is slowly opened, and the opening degree is controlled by PID based on the difference between the demand value and the actual rate value.
[0047] 5. When the vacuum level inside the vacuum chamber is less than 1E2Pa, open the first regulating valve 101;
[0048] 6. Close the third regulating valve 210, the fourth regulating valve 220, and the first regulating valve;
[0049] 7. When the vacuum level inside the vacuum chamber is less than 1E1Pa, start the molecular pump 102. After the molecular pump 102 is started, the slow vacuuming can be completed.
[0050] The slow breaking process is as follows:
[0051] 1. Close the first regulating valve 101, the molecular pump 102, the second regulating valve 103, and the pump body 105 in sequence;
[0052] 2. Open the sixth regulating valve 301;
[0053] 3. Set the proportional valve 300 at 0.01MPa;
[0054] 4. Slowly open the fourth regulating valve 220, and perform PID control on the opening degree based on the difference between the preset rate of change and the actual rate of change.
[0055] 5. When the fourth regulating valve 220 is fully opened, the speed regulation during vacuum breaking is achieved by adjusting the gas supply pressure of the electric proportional valve 300.
[0056] 6. When the vacuum level inside the vacuum chamber is greater than 1E5Pa, close the sixth regulating valve 301, the proportional valve 300, and the fourth regulating valve 220 in sequence to complete the slow breaking of the vacuum chamber.
[0057] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A vacuum air extraction device, characterised in that, include: The first pipeline (10) has one end connected to the pump body (105) and the other end connected to the vacuum chamber. The first pipeline (10) is provided with a first regulating valve (101) and a molecular pump (102) in sequence along the gas flow direction. The first pipeline (10) has a first split point (10a) between the pump body (105) and the molecular pump (102). The second pipeline (20) includes a parallel flow section (21), a first branch section (22), and a second branch section (23). The parallel flow section (21) is provided with a third regulating valve (210) and has a first end connected to a first diversion point (10a) and a second end located away from the first end. The parallel flow section (21) is provided with a second diversion point (21a) between the third regulating valve (210) and the second end. One end of the first branch section (22) and the second branch section (23) are both connected to the second end of the parallel flow section (21), and the other end is both connected to the vacuum chamber. The first branch section (22) is provided with a fourth regulating valve (220), and the second branch section (23) is provided with a fifth regulating valve (230). The third pipeline (30) is connected at one end to an external nitrogen cylinder and at the other end to the second branch point (21a), and a proportional valve (300) is provided on the third pipeline (30).
2. A vacuum air extractor as claimed in claim 1, wherein: The first pipeline (10) is also provided with a second regulating valve (103), which is located between the molecular pump (102) and the first split point (10a).
3. A vacuum air extractor as claimed in claim 1, wherein: The third pipeline (30) is also provided with a sixth regulating valve (301), which is located between the proportional valve (300) and the second diversion point (21a).
4. A vacuum air extractor as claimed in claim 1, wherein: The first regulating valve (101), the second regulating valve (103), the third regulating valve (210) and the sixth regulating valve (301) are all pneumatic valves.
5. A vacuum air extractor as claimed in claim 4, wherein: The first regulating valve (101) is a pneumatic slide gate valve, and the second regulating valve (103), the third regulating valve (210) and the sixth regulating valve (301) are all pneumatic angle valves.
6. The vacuum pumping device according to claim 1, characterized in that: The third regulating valve (210), the fourth regulating valve (220) and the fifth regulating valve (230) are all electric valves.
7. A vacuum pumping device according to claim 6, characterized in that: The third regulating valve (210) and the fifth regulating valve (230) are both configured as electric angle valves including a stepper motor and a reducer.
8. A vacuum pumping device according to claim 6, characterized in that: The fourth regulating valve (220) is an electric fine-tuning valve controlled by a stepper motor.
9. A vacuum pumping device according to claim 1, characterized in that: The vacuum pumping device also includes a gauge tube (40) and a control unit that is communicatively connected to the gauge tube (40). The control unit is configured to control the opening and closing degree of the valves on the first pipeline (10), the second pipeline (20) and the third pipeline (30) based on the vacuum value data in the vacuum chamber read by the gauge tube (40).
10. A vacuum pumping device according to claim 9, characterized in that: The control unit includes a host computer and a PLC connected via communication.