Near-infrared unit vacuumizing system of coronagraph

Abstract

The invention discloses a coronagraph near-infrared unit vacuumizing system which comprises a vacuum Dewar, a vacuum chamber valve, a roughing pump unit system, a main pump unit system and a control system. The vacuum Dewar is connected with the roughing pump unit system and the main pump unit system through the vacuum chamber valve and the three-way switching valve, and the three-way switching valve enables the vacuum Dewar to switch the connection state between the roughing pump unit system and the main pump unit system. The rough pump unit system and the main pump unit system are respectively composed of a plurality of pipelines, valves and pumps, and are used for extracting air from the vacuum Dewar to enable the vacuum Dewar to reach a preset vacuum degree; the control system collects the vacuum degree numerical value of the vacuum Dewar and controls the vacuum chamber valve and the opening and closing of all valves and pumps in the roughing pump unit system and the main pump unit system; based on a mechanical pump, a molecular pump and an electrical control system, the technical design of a multi-station, automatic operation and oil-free high-vacuum system is realized.

Description

Technical Field

[0001] The invention relates to a vacuum sealing technology, and in particular to a vacuum pumping system for a coronagraph near-infrared unit. Background Art

[0002] The intensity of light radiated by stars outside the solar system is 10 times that of light reflected by planets. 6 ~10 10 The light from the planets will be drowned out by the strong background light of the star, posing a challenge to direct exoplanet imaging. A key factor limiting direct exoplanet imaging is diffraction caused by factors such as the telescope aperture. High-contrast coronagraph systems can weaken or effectively suppress the diffracted light from stars. Therefore, high-contrast coronagraphs are key to direct exoplanet imaging. The near-infrared instrument, the core unit of the coronagraph, limits its performance and lifespan.

[0003] At present, during the operation of the coronagraph, the near-infrared components need to be vacuumed. The main functions of the vacuum system are: (1) to simulate the space working environment. Generally, the orbital environment pressure of the near-infrared components is in the range of ultra-high vacuum to very high vacuum. Considering the economic rationality of creating a simulated environment, the working pressure of the coronagraph optical component test is generally selected as 10 -3 ~10 - 5 Pa; (2) The Dewar of the near-infrared component requires a vacuum environment to reduce its heat exchange with the outside world, thereby reducing its liquid nitrogen consumption and maintaining low temperature.

[0004] Existing vacuum systems, such as the WZM oil-free ultra-high vacuum environment simulation test device developed by the 510 Research Institute of China Aerospace Corporation, can achieve a maximum vacuum degree of 4.8×10 -8 Pa, the system operation process can be automated, but the device is bulky and expensive; the multi-station high vacuum exhaust leak detection table produced by Beijing Zhongke Keyi Technology Development Co., Ltd. has 6 stations, but the vacuum degree can only reach 10Pa, and it is manually operated. The above-mentioned ultra-vacuum acquisition systems cannot meet the vacuum system requirements of near-infrared component life testing. Summary of the Invention

[0005] The purpose of the present invention is to provide a vacuum pumping system for a near-infrared unit of a coronagraph, which realizes the design of a multi-station, automated operation, and oil-free high vacuum system.

[0006] In order to achieve the above functions, the present invention designs a coronagraph near-infrared unit vacuum pumping system, including a vacuum dewar 1, a vacuum chamber valve 2, a roughing pump unit system, a main pump unit system, and a control system;

[0007] The vacuum dewar 1 is connected to the roughing pump unit system and the main pump unit system through the vacuum chamber valve 2 and the three-way switching valve, wherein the output port of the vacuum dewar 1 is connected to one end of the vacuum chamber valve 2, and the vacuum chamber valve 2 serves as the switching gas path of the vacuum dewar 1; the other end of the vacuum chamber valve 2 is connected to the input port of the three-way switching valve, and the roughing pump unit system and the main pump unit system are respectively connected to the two output ports of the three-way switching valve. The three-way switching valve switches the connection state of the vacuum dewar 1 between the roughing pump unit system and the main pump unit system;

[0008] The roughing pump unit system and the main pump unit system are respectively composed of a number of pipes, valves and pumps, which evacuate the vacuum dewar 1 to reach a preset vacuum degree; the control system is connected with the vacuum dewar 1, the vacuum chamber valve 2, the roughing pump unit system and the main pump unit system, collects the vacuum degree value of the vacuum dewar 1 in real time, sends control instructions, and controls the vacuum chamber valve 2, as well as the switches of the valves and pumps in the roughing pump unit system and the main pump unit system.

[0009] As a preferred technical solution of the present invention: the roughing pump unit system includes an oil filter 13, a mechanical pump 11, a mechanical pump air release valve 12, a mechanical pump bellows 8-1, an oil mist condensation trap 14, a roughing valve 6, and a pre-vacuum pipe 4;

[0010] The connection relationship of the roughing pump unit system is as follows:

[0011] One end of the roughing valve 6 is connected to an output port of the three-way switching valve through the pre-vacuum pipe 4, and the other end of the roughing valve 6 is connected to one side of the oil mist condensation trap 14. The other side of the oil mist condensation trap 14 is connected to the mechanical pump 11 through the mechanical pump bellows 8-1, and the oil filter 13 and the mechanical pump air release valve 12 are respectively connected to the mechanical pump 11.

[0012] As a preferred technical solution of the present invention: the main pump unit system includes a main vacuum pipe 3, a high vacuum valve 5, a molecular pump vent valve 7, a molecular pump 9, a molecular pump bellows 8-2, and a front stage valve 10;

[0013] The connection relationship of the main pump unit system is as follows:

[0014] One end of the high vacuum valve 5 is connected to an output port of the three-way switching valve through the main vacuum pumping pipe 3, and the other end of the high vacuum valve 5 is connected to the molecular pump 9 by being connected to the molecular pump bellows 8-2, and one end of the molecular pump air release valve 7 and the front-stage valve 10 are connected to the molecular pump 9, and the other end of the front-stage valve 10 is connected to one side of the oil mist condensation trap 14 in the roughing pump unit system.

[0015] As a preferred technical solution of the present invention: the vacuum chamber valve 2, the high vacuum valve 5, the roughing valve 6 and the front stage valve 10 adopt high vacuum pneumatic baffle straight-through valves.

[0016] As a preferred technical solution of the present invention, the molecular pump air release valve 7 and the mechanical pump air release valve 12 adopt electromagnetic pressure difference inflation valves.

[0017] As a preferred technical solution of the present invention: the control system includes a bus, a digital vacuum gauge, an alarm device, a programmable controller, a roughing pump unit system controller, and a main pump unit system controller; the programmable controller communicates with the digital vacuum gauge, the roughing pump unit system controller, and the main pump unit system controller via the bus;

[0018] The digital vacuum gauge is installed in the vacuum dewar 1 to collect the vacuum value in the vacuum dewar 1; the programmable controller controls the on and off of each valve and equipment in the roughing pump unit system controller and the main pump unit system controller; the alarm device is connected to the programmable controller and sends out alarm information according to the instructions of the programmable controller.

[0019] As a preferred technical solution of the present invention: according to the control instructions of the control system, the vacuum dewar 1 is subjected to the following pumping process to reach a preset vacuum degree:

[0020] Open the vacuum chamber valve 2, close the high vacuum valve 5 and the front stage valve 10 first, open the roughing valve 6, connect the vacuum dewar 1 to the pre-vacuum pipe 4 with the three-way switching valve, and use the roughing pump system to pump air;

[0021] When the vacuum degree of the vacuum dewar 1 reaches the preset rough vacuum degree, the rough valve 6 will be closed, and then the high vacuum valve 5 and the front-stage valve 10 will be opened, and the vacuum dewar 1 will be switched to be connected to the main vacuum pipe 3, and the main pump unit system will be used to pump air until the vacuum degree of the vacuum dewar 1 reaches the preset main vacuum degree.

[0022] As a preferred technical solution of the present invention: during the evacuation of the vacuum dewar, the molecular pump bleed valve 7 is opened when the molecular pump 9 is shut down to inflate it; the mechanical pump bleed valve 12 is opened when the mechanical pump 11 is shut down to inflate it.

[0023] As a preferred technical solution of the present invention: the rough vacuum degree is 10 -1 Pa.

[0024] As a preferred technical solution of the present invention: the range of the main vacuum degree is 10 -3 ~10 -5 Pa.

[0025] Beneficial effects: Compared with the prior art, the advantages of the present invention include:

[0026] 1. The roughing pump system and the main pump system of the present invention can respectively make the vacuum value inside the vacuum dewar reach two preset values: 10 -1Pa, 10 -3 ~10 -5 Pa, solve the problem of substandard vacuum degree of existing vacuum equipment;

[0027] 2. Most existing vacuum equipment is manually operated, which consumes a lot of manpower and material resources during testing. Therefore, the vacuum system mechanical pump, molecular pump, ion pump, and electrical control system provided by the present invention realize automatic operation;

[0028] 3. The existing vacuum pumping devices are bulky, and the price of the vacuum pumping systems that can meet the high vacuum or ultra-high vacuum levels is relatively expensive. In addition, the equipment is special and is not suitable for the vacuum pumping systems required for small-volume (no more than 10L) sealed spaces. The system designed by the present invention has the characteristics of small size, simple operation, universal equipment, simple connection relationship, easy replacement and maintenance of equipment, and convenient disassembly, which reduces the cost of the vacuum pumping system. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 2. It is a schematic diagram of a vacuum pumping system of a coronagraph near-infrared unit provided according to an embodiment of the present invention;

[0030] Figure 1 Middle: 1. Vacuum dewar; 2. Vacuum chamber valve; 3. Main vacuum pipe; 4. Pre-vacuum pipe; 5. High vacuum valve; 6. Roughing valve; 7. Molecular pump bleed valve; 8-1. Mechanical pump bellows; 8-2. Molecular pump bellows; 9. Molecular pump; 10. Fore valve; 11. Mechanical pump; 12. Mechanical pump bleed valve; 13. Oil filter; 14. Oil mist condensation trap;

[0031] Figure 2 is a block diagram of a control system provided according to an embodiment of the present invention;

[0032] Figure 3 1 is a schematic diagram of a control system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0034] The embodiment of the present invention provides a near-infrared unit vacuum pumping system for a coronagraph, referring to Figure 1 , including vacuum dewar 1, vacuum chamber valve 2, roughing pump unit system, main pump unit system, and control system;

[0035] The vacuum dewar 1 is connected to the roughing pump unit system and the main pump unit system through the vacuum chamber valve 2 and the three-way switching valve, wherein the output port of the vacuum dewar 1 is connected to one end of the vacuum chamber valve 2, and the vacuum chamber valve 2 serves as the switching gas path of the vacuum dewar 1; the other end of the vacuum chamber valve 2 is connected to the input port of the three-way switching valve, and the roughing pump unit system and the main pump unit system are respectively connected to the two output ports of the three-way switching valve. The three-way switching valve switches the connection state of the vacuum dewar 1 between the roughing pump unit system and the main pump unit system;

[0036] The roughing pump unit system and the main pump unit system are respectively composed of a number of pipes, valves and pumps, which evacuate the vacuum dewar 1 to reach a preset vacuum degree; the control system is connected with the vacuum dewar 1, the vacuum chamber valve 2, the roughing pump unit system and the main pump unit system, collects the vacuum degree value of the vacuum dewar 1 in real time, sends control instructions, and controls the vacuum chamber valve 2, as well as the switches of the valves and pumps in the roughing pump unit system and the main pump unit system.

[0037] The roughing pump unit system includes an oil filter 13, a mechanical pump 11, a mechanical pump air release valve 12, a mechanical pump bellows 8-1, an oil mist condensation trap 14, a roughing valve 6, and a pre-vacuum pipe 4;

[0038] The connection relationship of the roughing pump unit system is as follows:

[0039] One end of the roughing valve 6 is connected to an output port of the three-way switching valve through the pre-vacuum pipe 4, and the other end of the roughing valve 6 is connected to one side of the oil mist condensation trap 14. The other side of the oil mist condensation trap 14 is connected to the mechanical pump 11 through the mechanical pump bellows 8-1, and the oil filter 13 and the mechanical pump air release valve 12 are respectively connected to the mechanical pump 11.

[0040] The main pump unit system includes a main vacuum pipe 3, a high vacuum valve 5, a molecular pump vent valve 7, a molecular pump 9, a molecular pump bellows 8-2, and a front stage valve 10;

[0041] The connection relationship of the main pump unit system is as follows:

[0042] One end of the high vacuum valve 5 is connected to an output port of the three-way switching valve through the main vacuum pumping pipe 3, and the other end of the high vacuum valve 5 is connected to the molecular pump 9 by being connected to the molecular pump bellows 8-2, and one end of the molecular pump air release valve 7 and the front-stage valve 10 are connected to the molecular pump 9, and the other end of the front-stage valve 10 is connected to one side of the oil mist condensation trap 14 in the roughing pump unit system.

[0043] The mechanical pump bellows 8 - 1 between the molecular pump 9 and the mechanical pump 11 is used to prevent the vibration of the mechanical pump 11 from being directly transmitted to the molecular pump 9 and affecting the life of the molecular pump 9 .

[0044] The vacuum chamber valve 2, high vacuum valve 5, roughing valve 6, and fore valve 10 all function as on-off valves in the near-infrared unit's vacuum system. They utilize high-vacuum pneumatic baffle valves. The molecular pump bleed valve 7 and the mechanical pump bleed valve 12 utilize electromagnetic pressure differential inflation valves.

[0045] Reference Figure 2 , use power supply to supply power to each device in control system, roughing pump unit system and main pump unit system. The control system includes bus, digital vacuum gauge, alarm device, programmable controller, roughing pump unit system controller and main pump unit system controller; refer to Figure 3 , the programmable controller communicates with the digital vacuum gauge, the roughing pump unit system controller, and the main pump unit system controller through the bus;

[0046] The digital vacuum gauge is installed in the vacuum dewar 1 to collect the vacuum value in the vacuum dewar 1; the programmable controller controls the on and off of each valve and equipment in the roughing pump unit system controller and the main pump unit system controller; the alarm device is connected to the programmable controller and sends out alarm information according to the instructions of the programmable controller.

[0047] According to the control instructions of the control system, the vacuum dewar 1 is subjected to the following pumping process to reach a preset vacuum degree: In one embodiment, the rough vacuum degree is preset to 10 -1 Pa.

[0048] Open the vacuum chamber valve 2, close the high vacuum valve 5 and the front stage valve 10 first, open the roughing valve 6, connect the vacuum dewar 1 to the pre-vacuum pipe 4 with the three-way switching valve, and use the roughing pump system to pump air;

[0049] At this time, the gas is extracted from the vacuum dewar 1, and passes through the vacuum chamber valve 2, the pre-vacuum pipe 4, the roughing valve 6, the oil mist condensation trap 14, the mechanical pump bellows 8-1, the mechanical pump 11, and the oil filter 13 in sequence, and is finally discharged from the system. The oil mist condensation trap 14 and the oil filter 13 serve as oil removal devices. The oil mist in the gas is condensed and filtered through the oil mist condensation trap 14 and the oil filter 13, and is thus removed, thereby achieving an oil-free high vacuum environment in the system.

[0050] When the vacuum degree of the vacuum dewar 1 reaches the preset rough vacuum degree, the roughing valve 6 will be closed, and then the high vacuum valve 5 and the front stage valve 10 will be opened, and the vacuum dewar 1 will be switched to connect to the main vacuum pipe 3, and the main pump unit system will be used to pump air until the vacuum degree of the vacuum dewar 1 reaches the preset main vacuum degree. In one embodiment, the range of the main vacuum degree is preset to 10 -3 ~10 -5 Pa.

[0051] At this time, the gas is extracted from the vacuum dewar 1, and passes through the vacuum chamber valve 2, the main vacuum pipe 3, the high vacuum valve 5, the molecular pump bellows 8-2, the molecular pump 9, the front stage valve 10, the oil mist condensation trap 14, the mechanical pump bellows 8-1, the mechanical pump 11, the oil filter 13, and finally discharged from the system.

[0052] When the vacuum degree of the vacuum dewar 1 is lower than the upper limit of the roughing pump unit system, the programmable controller PLC control system is in the roughing state, that is, the roughing valve 6 of the vacuum dewar 1 connected to the roughing pump unit system is opened, so that the vacuum dewar 1 is mounted on the mechanical pump 11 of the roughing system for exhaust; when the vacuum degree of the vacuum dewar 1 is higher than the upper limit of the roughing control system, the programmable controller PLC controls the vacuum dewar 1 to be in the main exhaust state, that is, the high vacuum valve 5 and the fore-stage valve 10 connected to the vacuum dewar 1 are opened, so that the vacuum dewar 1 is mounted on the molecular pump 9 of the main exhaust system for exhaust.

[0053] During the vacuum dewar's evacuation process, the molecular pump bleed valve 7 is opened when the molecular pump 9 stops to inflate it; the mechanical pump bleed valve 12 is opened when the mechanical pump 11 stops to inflate it to prevent oil vapor from flowing back into the vacuum dewar 1.

[0054] In summary, the present invention adopts the technical design of the automated operation and oil-free high vacuum system composed of a mechanical pump, a molecular pump, and an electrical control system. On the premise of meeting the vacuum degree standard, it changes the original manual operation of vacuuming and has a fully automated function, saving a lot of manpower and material resources. At the same time, it is small in size, simple to operate, easy to disassemble, and effectively extends the service life of the molecular pump.

[0055] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the spirit of the present invention.

Claims

1. A vacuum pumping system for a near-infrared coronagraph, characterized in that: It includes a vacuum dewar (1), a vacuum chamber valve (2), a roughing pump unit system, a main pump unit system, and a control system; The vacuum dewar (1) is connected to the roughing pump unit system and the main pump unit system respectively through the vacuum chamber valve (2) and the three-way switching valve, wherein the output port of the vacuum dewar (1) is connected to one end of the vacuum chamber valve (2), and the vacuum chamber valve (2) serves as the switching air path of the vacuum dewar (1); the other end of the vacuum chamber valve (2) is connected to the input port of the three-way switching valve, and the roughing pump unit system and the main pump unit system are respectively connected to the two output ports of the three-way switching valve, and the three-way switching valve switches the connection state of the vacuum dewar (1) between the roughing pump unit system and the main pump unit system; The roughing pump unit system and the main pump unit system are respectively composed of a number of pipes, valves, and pumps, and are used to evacuate the vacuum dewar (1) to achieve a preset vacuum degree; the control system is connected to the vacuum dewar (1), the vacuum chamber valve (2), the roughing pump unit system, and the main pump unit system, and collects the vacuum degree value of the vacuum dewar (1) in real time, sends control instructions, and controls the vacuum chamber valve (2), as well as the switches of the valves and pumps in the roughing pump unit system and the main pump unit system.

2. A coronagraph near-infrared unit vacuum pumping system according to claim 1, characterized in that: The roughing pump unit system comprises an oil filter (13), a mechanical pump (11), a mechanical pump air release valve (12), a mechanical pump bellows (8-1), an oil mist condensation trap (14), a roughing valve (6), and a pre-vacuum pipe (4); The connection relationship of the roughing pump unit system is as follows: One end of the roughing valve (6) is connected to an output port of the three-way switching valve through a pre-vacuuming pipe (4), and the other end of the roughing valve (6) is connected to one side of the oil mist condensation trap (14). The other side of the oil mist condensation trap (14) is connected to the mechanical pump (11) through a mechanical pump bellows (8-1), and the oil filter (13) and the mechanical pump air release valve (12) are respectively connected to the mechanical pump (11).

3. A coronagraph near-infrared unit vacuum pumping system according to claim 2, characterized in that: The main pump unit system comprises a main vacuum pipe (3), a high vacuum valve (5), a molecular pump vent valve (7), a molecular pump (9), a molecular pump bellows (8-2), and a front stage valve (10); The connection relationship of the main pump unit system is as follows: One end of the high vacuum valve (5) is connected to an output port of the three-way switching valve through a main vacuum pumping pipe (3), and the other end of the high vacuum valve (5) is connected to the molecular pump (9) by being connected to a molecular pump bellows (8-2), and one end of the molecular pump vent valve (7) and the front stage valve (10) are connected to the molecular pump (9), and the other end of the front stage valve (10) is connected to one side of the oil mist condensation trap (14) in the roughing pump unit system.

4. A coronagraph near-infrared unit vacuum pumping system according to claim 3, characterized in that: The vacuum chamber valve (2), the high vacuum valve (5), the roughing valve (6) and the front stage valve (10) adopt high vacuum pneumatic baffle straight-through valves.

5. The vacuum pumping system for a coronagraph near-infrared unit according to claim 3, characterized in that: The molecular pump air release valve (7) and the mechanical pump air release valve (12) adopt electromagnetic pressure difference inflation valves.

6. A coronagraph near-infrared unit vacuum pumping system according to claim 1, characterized in that: The control system includes a bus, a digital vacuum gauge, an alarm device, a programmable controller, a roughing pump unit system controller, and a main pump unit system controller; the programmable controller communicates with the digital vacuum gauge, the roughing pump unit system controller, and the main pump unit system controller through the bus; A digital vacuum gauge is installed in the vacuum dewar (1) to collect the vacuum value in the vacuum dewar (1); a programmable controller controls the on / off of valves and equipment in the roughing pump unit system controller and the main pump unit system controller; an alarm device is connected to the programmable controller and issues an alarm message according to the programmable controller instruction.

7. The vacuum pumping system for a coronagraph near-infrared unit according to claim 3, characterized in that: According to the control instructions of the control system, the vacuum dewar (1) is subjected to the following evacuation process to reach the preset vacuum degree: Open the vacuum chamber valve (2), first close the high vacuum valve (5) and the front stage valve (10), open the roughing valve (6), connect the vacuum dewar (1) to the pre-vacuum pipe (4) through the three-way switching valve, and use the roughing pump system to pump air; When the vacuum degree of the vacuum dewar (1) reaches the preset rough vacuum degree, the roughing valve (6) will be closed, and then the high vacuum valve (5) and the front stage valve (10) will be opened, and the vacuum dewar (1) will be switched to be connected to the main vacuum pipe (3), and the main pump unit system will be used to pump air until the vacuum degree of the vacuum dewar (1) reaches the preset main vacuum degree.

8. A coronagraph near-infrared unit vacuum pumping system according to claim 7, characterized in that: During the evacuation process of the vacuum dewar, the molecular pump bleed valve (7) is opened when the molecular pump (9) stops, and the molecular pump is inflated; the mechanical pump bleed valve (12) is opened when the mechanical pump (11) stops, and the mechanical pump is inflated.

9. The vacuum pumping system for a coronagraph near-infrared unit according to claim 7, characterized in that: The rough vacuum degree is 10 -1 Pa.

10. The vacuum pumping system for a coronagraph near-infrared unit according to claim 7, characterized in that: The range of the main vacuum degree is 10 -3 ~10 -5 Pa.

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