Rapid regeneration low-temperature pump

Abstract

The invention relates to a quick-regeneration low-temperature pump which comprises a low-temperature pump body and further comprises a heat pipe and a heater, the heat pipe penetrates through an air cylinder shell of the low-temperature pump body and makes contact with a first-stage cold head and a second-stage cold head in the low-temperature pump body, and the heater is located outside the low-temperature pump body and makes contact with the heat pipe. Heat conduction is conducted through the heat pipe, the heater is located on the outer side of the low-temperature pump body, and therefore the heater with the larger area and power can be arranged, heat supplied to a cold head in unit time is increased, regeneration time is shortened, and production efficiency is improved; the heater is arranged on the outer side of the cryopump body, enough space is reserved between the heater and the heat pipe for insulation treatment, and normal work of the cryopump is prevented from being affected by short circuit of a heating rod in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of cryogenic pumps, in particular to a fast-regenerating cryogenic pump. Background Art

[0002] Cryopumps are storage vacuum pumps with extremely low temperature surfaces inside the pumps, which can capture gases through condensation and adsorption to achieve ultra-high vacuum. Cryopumps can obtain clean vacuum with the highest pumping rate and the lowest ultimate pressure, and are widely used in the research and production of semiconductors and integrated circuits, as well as molecular beam research, vacuum coating equipment, vacuum surface analysis instruments, ion implanters, and space simulation devices.

[0003] When the cryopump reaches saturation capacity after long-term operation, the pumping speed drops sharply. At this time, it is necessary to stop the pump and raise the temperature to release the gas adsorbed on the cryopanel and restore the original pumping performance. Heating the temperature and using the pre-pump to pump out the released condensed and adsorbed gas is called "regeneration".

[0004] There are several ways to regenerate: ① Natural heating method: Turn off the power of the refrigerator and use the heat of the pump wall to slowly heat up the cryopump. The temperature rises very slowly at the beginning. When the pressure in the pump rises to the point where convection heat transfer takes effect, the heating rate accelerates and finally reaches a stable temperature rise value.

[0005] ② Venting and heating method: After stopping the refrigerator, open the vent valve to let in clean and dry air to quickly heat up the cryopump cryopanel ③ Electric heating method: Electric heaters are installed on the first and second stage cold heads in the cryopump. During regeneration, electric heating is applied to quickly heat up the cryopanel to shorten the regeneration time.

[0006] The existing electric heating method uses an electric heating rod with a metal shell to penetrate into the cryopump. Inside the empty metal shell are multiple heating wires and silicone. The silicone is located between the heating wires and the metal shell to prevent the heating wires from contacting each other or the heating rod shell, thereby preventing a short circuit.

[0007] The thinner the thickness of the silicone, the better the thermal conductivity, but the electric heating rod is more likely to short-circuit, thus causing electromagnetic interference; the thicker the silicone, the less likely it is to short-circuit, but the worse the thermal conductivity. Because the thermal conductivity of silicone is poor, and the thickness of the silicone in the existing electric heating rod is large, the heating capacity of the electric heating rod to the cold head cannot be further increased, and the time required for electric heating regeneration is longer. In addition, due to the priority of the internal space of the cryopump and the need to reduce the number of sealing interfaces, the heating capacity cannot be increased by increasing the number of heating rods. Summary of the invention

[0008] The present invention provides a fast-regenerating cryogenic pump, which solves the above-mentioned technical problems.

[0009] A fast regeneration cryogenic pump comprises a cryogenic pump body, a heat pipe and a heater. The heat pipe passes through the cylinder shell of the cryogenic pump body and contacts the primary cold head and the secondary cold head inside the cryogenic pump body. The heater is located outside the cryogenic pump body and contacts the heat pipe.

[0010] Furthermore, a portion of the heat pipe extending out of the cryopump body is formed with a flat plate portion, the heater is in contact with the flat plate portion, and the heater is an electric heater.

[0011] Furthermore, it also includes a first fixing device and a second fixing device, wherein the first fixing device fixes the heat pipe to the first-level cold head, and the second fixing device fixes the heat pipe to the second-level cold head; The heat pipe is fixedly connected to the cylinder housing, and the heater is fixedly connected to the heat pipe.

[0012] Furthermore, the shell of the heat pipe is made of aluminum, copper, aluminum alloy or copper alloy, a capillary structure is fixed inside the shell of the heat pipe, and the heat pipe is filled with a working fluid.

[0013] Furthermore, it also includes a heat insulation sleeve, which is sleeved on the portion of the heat pipe extending out of the cryopump body and the outside of the heater.

[0014] Furthermore, it also includes a heat insulation layer, which covers the portion of the heat pipe extending out of the cryopump body and the surface of the heater, the heat insulation layer is in contact with the cylinder shell, and the heat insulation sleeve is located outside the heat insulation layer.

[0015] Furthermore, the thermal insulation sleeve is a hard outer shell, the thermal insulation sleeve is fixedly connected to the cylinder shell, the thermal insulation sleeve is not in contact with the heat pipe and the heater, and a vacuum environment is formed inside the thermal insulation sleeve.

[0016] Furthermore, it also includes a radiator, an exhaust valve and a vent valve, the insulation sleeve is fixedly connected to the exhaust valve and the vent valve respectively, the interior of the insulation sleeve is connected to the exhaust valve and the vent valve respectively, the exhaust valve is connected to the vacuum pump, and the radiator is in contact with the heat pipe.

[0017] Furthermore, the heat sink includes a base and fins, the base is attached to and fixedly connected to the flat plate portion, and the fins are integrally formed with the base.

[0018] Furthermore, a fan is also included, the heat insulation sleeve is fixedly connected to the two ventilation valves respectively, and the outer side of at least one ventilation valve is fixedly connected to and communicated with the fan.

[0019] The present invention has the following advantages: 1. Heat conduction is carried out through heat pipes, so that the heater is located outside the cryopump body, so that a heater with a larger area and power can be set, which increases the heat provided to the cold head per unit time, reduces the regeneration time, and improves production efficiency; 2. The heater is outside the cryopump body, and there is enough space between the heater and the heat pipe for insulation treatment, which avoids the short circuit of the heating rod in the prior art affecting the normal operation of the cryopump and improves the reliability of the cryopump; 3. Use thermal insulation sleeves to insulate the heat pipe and heater, reducing the heat exchange between the heat pipe and the outside world when the cryopump is adsorbing at low temperatures and heating at low temperatures; 4. After the working fluid in the heat pipe melts, the heat in the air is used to heat the cold head, saving energy and avoiding overheating of the cold head; 5. A thicker insulating layer can be used between the heat pipe and the heater, or the heater can be provided with an insulating casing. The heat pipe is not energized, thus avoiding electromagnetic interference to the equipment inside and outside the pump caused by the short circuit in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0021] Figure 1 : Schematic diagram of the three-dimensional structure of the cryopump body; Figure 2 : A schematic diagram of the three-dimensional structure of the present invention with some components removed; Figure 3 : A schematic cross-sectional view of the present invention; Figure 4 :exist Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle; Figure 5 : A cross-sectional view of the heating device in Example 2; Figure 6 : A cross-sectional view of the heating device in Example 3; Figure 7 : A cross-sectional view of the heating device in the fourth embodiment; Figure 8 :exist Figure 7 Cross-sectional view at BB in the middle. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and examples: Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention. Embodiment 1: like Figures 1 to 4 As shown, this embodiment provides a fast regeneration cryogenic pump, including a cryogenic pump body 1, and also includes a heat pipe 2 and a heater 3. The heat pipe 2 passes through the cylinder housing 10 of the cryogenic pump body 1, and the heat pipe 2 is in contact with the primary cold head 14 and the secondary cold head 15 inside the cryogenic pump body 1. The heater 3 is located outside the cryogenic pump body 1 and in contact with the heat pipe 2.

[0025] Optionally, a heat pipe 2 is used to contact the primary cold head 14 and the secondary cold head 15 at the same time, such as Figure 2 and Figure 3 shown.

[0026] Optionally, a plurality of heat pipes 2 are used, and one heat pipe 2 is in contact with only one of the primary cold head 14 and the secondary cold head 15 , which is not shown in the figure.

[0027] Furthermore, the portion of the heat pipe 2 extending out of the cryopump body 1 is formed with a flat plate portion 21, and the heater 3 is in contact with the flat plate portion 21, and the heater 3 is an electric heater. The flat plate portion 21 increases the surface area, thereby increasing the contact area with the heater 3. The flat plate portion 21 has a greater heat conduction per unit time, so that the heater 3 matched therewith can adopt a greater heating power.

[0028] Optionally, the heat pipe 2 is fixed to the primary cold head 14 by brazing, and the heat pipe 2 is fixed to the secondary cold head 15 by brazing.

[0029] Optionally, it further includes a first fixing device 4 and a second fixing device 5 , wherein the first fixing device 4 fixes the heat pipe 2 to the primary cold head 14 , and the second fixing device 5 fixes the heat pipe 2 to the secondary cold head 15 .

[0030] Preferably, if Figure 2 and Figure 3 As shown, the first fixing device 4 and the second fixing device 5 can be a fixing block or a clamp. The fixing block is fixedly connected to the cold head by screws; the clamp clamps the cold head and the heat pipe 2 inside it tightly so that they are in contact with each other.

[0031] Preferably, thermally conductive materials such as silicone grease are used to fill tiny gaps on the surface between the heat pipe 2 and the first fixing device 4 and the second fixing device 5 .

[0032] Furthermore, the heat pipe 2 is fixedly connected to the cylinder housing 10, and the heater 3 is fixedly connected to the heat pipe 2. The heat pipe 2 and the cylinder housing 10 are sealed.

[0033] Preferably, the heat pipe 2 is fixed to the cylinder housing 10 by welding.

[0034] Furthermore, the shell of the heat pipe 2 is made of aluminum, copper, aluminum alloy or copper alloy, a capillary structure is fixed inside the shell of the heat pipe 2, and the heat pipe 2 is filled with a working fluid. The capillary structure is a prior art, such as a sintered structure, a groove, etc., which uses capillary phenomena to move the liquid.

[0035] Preferably, the melting point of the working fluid in the heat pipe 2 is lower than -100°C and the critical temperature is higher than 0°C.

[0036] More preferably, the working fluid in the heat pipe 2 can be ethanol, Freon (such as R23, ‌R508B, etc.), and other low-temperature and ultra-low-temperature refrigerants (such as R600a, etc.).

[0037] During operation, the temperature inside the cryopump body 1 is lowered, so that the cold shield 12 and the cold umbrella 13 adsorb molecules in the gas at low temperature. During operation, since the temperature of the cryopump body 1 is too low, the working fluid in the heat pipe 2 will be solidified and the phase change will stop. At this time, the heat pipe 2 only exchanges heat with the outside through heat conduction, and the thermal conductivity is greatly reduced, which reduces the impact of the temperature outside the cryopump body 1 on the inside, so that the inside of the cryopump body 1 can be smoothly lowered to the specified temperature.

[0038] During regeneration, the heater 3 heats the flat plate portion 21, and the heat is conducted along the metal heat pipe 2 to the contact point between the heat pipe 2 and the primary cold head 14 and the secondary cold head 15, so that the solidified working fluid in the heat pipe 2 melts. After the working fluid melts, the heat pipe 2 can smoothly change phase to conduct heat, and the thermal conductivity efficiency is greatly improved, so that a large amount of heat can be transferred to the primary cold head 14 and the secondary cold head 15 in a short time, so that the primary cold head 14 and the secondary cold head 15 are quickly heated up, shortening the regeneration time. Afterwards, according to the temperature sensor inside the cryopump body 1, when the specified temperature is reached, the heater 3 stops working.

[0039] Among them, the thermal conductivity of metal will increase at low temperatures, which is conducive to the heat pipe 2 to quickly melt the solidified working fluid.

[0040] It should be noted that the cryopump body 1 is a cryopump of the prior art, such as the cryopump disclosed in the Chinese invention patent with the authorization announcement number CN117489563B. The first-stage cold head 14 and the second-stage cold head 15 of the cryopump body 1 are respectively located inside the cylinder housing 10 and the outer housing 11, and the cylinder housing 10 and the outer housing 11 are fixedly connected. The cold shield 2 and the cold umbrella 3 of the cryopump body 1 are arranged inside the outer housing 11, and the end of the cylinder housing 10 is fixed to the base through the cold head base 16.

[0041] Embodiment 2: like Figures 1 to 5 As shown, this embodiment is a further improvement on the first embodiment, and further comprises a heat insulating sleeve 8 , wherein the heat insulating sleeve 8 is sleeved on the portion of the heat pipe 2 extending out of the cryopump body 1 and the outside of the heater 3 .

[0042] Furthermore, it also includes a heat insulation layer 6, which covers the portion of the heat pipe 2 extending out of the cryopump body 1 and the surface of the heater 3, the heat insulation layer 6 is in contact with the cylinder housing 10, and the heat insulation sleeve 8 is located outside the heat insulation layer 6. The heat insulation layer 6 is used to shield the air convection inside and outside it to reduce heat transfer.

[0043] Optionally, the thermal insulation layer 6 is made of silicone, which fits the portion of the heat pipe 2 extending out of the cryopump body 1 and the heater 3 , and the end of the silicone is bonded and fixed to the outer side of the cylinder housing 10 , so that the inside and outside of the thermal insulation layer 6 are sealed.

[0044] Optionally, the thermal insulation layer 6 is a thermal insulation coating, and thermal insulation is achieved by spraying the coating on a portion of the cryopump body 1 and the surface of the heater 3 .

[0045] Furthermore, the end of the heat insulating sleeve 8 is fixed and sealed to the cylinder housing 10, and the heat insulating sleeve 8 is elastic.

[0046] Preferably, the heat insulation sleeve 8 is a heat-insulating cotton with aluminum foil arranged inside, and the aluminum foil is used to reduce heat radiation.

[0047] During operation, the temperature inside the cryopump body 1 decreases, and the heat-insulating sleeve 8 reduces the cooling capacity lost by the portion of the heat pipe 2 extending out of the cryopump body 1; during regeneration, the heat-insulating sleeve 8 reduces the loss of heat generated by the heater 3. Through the heat-insulating effect, the heat-insulating sleeve 8 reduces the energy consumption.

[0048] Embodiment three: like Figures 1 to 4 and Figure 6 As shown, this embodiment is a further improvement on the first embodiment, and further comprises a heat insulating sleeve 8 , wherein the heat insulating sleeve 8 is sleeved on the portion of the heat pipe 2 extending out of the cryopump body 1 and the outside of the heater 3 .

[0049] Furthermore, the thermal insulation sleeve 8 is a hard shell, the thermal insulation sleeve 8 is fixedly connected to the cylinder housing 10, the thermal insulation sleeve 8 is not in contact with the heat pipe 2 and the heater 3, and a vacuum environment is formed inside the thermal insulation sleeve 8.

[0050] Preferably, the heat insulation sleeve 8 is fixed to the outer side of the cylinder housing 10 by welding.

[0051] Preferably, the inner wall of the thermal insulation sleeve 8 is silver-plated, and the silver coating is used to reduce heat radiation.

[0052] The inner cavity 80 of the heat-insulating sleeve 8 is in a vacuum state, and the thermal conductivity is extremely low. When working, the temperature inside the cryopump body 1 will decrease, and the heat-insulating sleeve 8 reduces the cooling capacity lost by the part of the heat pipe 2 extending out of the cryopump body 1; during regeneration, the heat-insulating sleeve 8 reduces the loss of heat generated by the heater 3. Through the heat-insulating effect, the heat-insulating sleeve 8 reduces the energy consumption.

[0053] Embodiment 4: like Figures 1 to 4 , Figure 7 and Figure 8 As shown, this embodiment is a further improvement on the first embodiment, and further comprises a heat insulating sleeve 8 , wherein the heat insulating sleeve 8 is sleeved on the portion of the heat pipe 2 extending out of the cryopump body 1 and the outside of the heater 3 .

[0054] Furthermore, the thermal insulation sleeve 8 is a hard shell, the thermal insulation sleeve 8 is fixedly connected to the cylinder housing 10, the thermal insulation sleeve 8 is not in contact with the heat pipe 2 and the heater 3, and a vacuum environment is formed inside the thermal insulation sleeve 8.

[0055] Preferably, the heat insulation sleeve 8 is fixed to the outer side of the cylinder housing 10 by welding.

[0056] Preferably, the inner wall of the thermal insulation sleeve 8 is silver-plated, and the silver coating is used to reduce heat radiation.

[0057] Furthermore, it also includes a radiator 9, an air extraction valve 81 and a vent valve 82, the heat insulation sleeve 8 is fixedly connected to the air extraction valve 81 and the vent valve 82 respectively, the interior of the heat insulation sleeve 8 is connected to the air extraction valve 81 and the vent valve 82 respectively, the air extraction valve 81 is connected to the vacuum pump, and the radiator 9 is in contact with the heat pipe 2. The radiator 9 does not contact the heat insulation sleeve 8.

[0058] Furthermore, the heat sink 9 includes a base 91 and fins 82. The base 91 is attached to and fixedly connected to the flat plate portion 21, and the fins 82 are integrally formed with the base 91. The fins 82 are used to increase the heat exchange area.

[0059] Preferably, the heat sink 9 is made of aluminum, copper, aluminum alloy or copper alloy.

[0060] Furthermore, a fan 83 is included. The heat insulation sleeve 8 is fixedly connected to the two ventilation valves 82 respectively, and the outer side of at least one ventilation valve 82 is fixedly connected and communicated with the fan 83.

[0061] Preferably, the fan 83 is an axial flow fan or a centrifugal fan.

[0062] During regeneration, the heater 3 heats the flat plate portion 21 , and the heat is conducted along the metal heat pipe 2 to the contact point between the heat pipe 2 and the primary cold head 14 and the secondary cold head 15 , so as to melt the solidified working fluid in the heat pipe 2 .

[0063] After the working fluid melts, the two vent valves 82 are opened to connect the inner cavity 80 of the heat insulation sleeve 8 with the outside, and air at room temperature enters the heat insulation sleeve 8. At this time, the heater 3 stops working, the fan 83 works, and the air flow blows over the surface of the fins 82 for heat exchange. By using the heat in the air to heat the primary cold head 14 and the secondary cold head 15, the power consumption of the heater 3 is reduced.

[0064] Before the cryopump body 1 works, the vent valve 82 and the fan 83 are closed. After that, the exhaust valve 81 is opened. After the vacuum pump evacuates the inner cavity 80, the exhaust valve 81 is closed. The vacuum pump can be an independent vacuum pump or a fore-stage pump (vacuum pump) matched with the cryopump.

[0065] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications made based on the present invention belong to the scope of protection claimed by the present invention.

Claims

1. A fast regenerating cryopump, comprising a cryopump body (1), characterized in that: It also includes a heat pipe (2) and a heater (3), wherein the heat pipe (2) passes through the cylinder housing (10) of the cryopump body (1), the heat pipe (2) is in contact with a primary cold head (14) and a secondary cold head (15) inside the cryopump body (1), and the heater (3) is located outside the cryopump body (1) and in contact with the heat pipe (2).

2. A fast regenerating cryopump according to claim 1, characterized in that: The portion of the heat pipe (2) extending out of the cryopump body (1) is formed with a flat plate portion (21), the heater (3) is in contact with the flat plate portion (21), and the heater (3) is an electric heater.

3. A fast regenerating cryopump according to claim 1, characterized in that: It also comprises a first fixing device (4) and a second fixing device (5), wherein the first fixing device (4) fixes the heat pipe (2) to the first-level cold head (14), and the second fixing device (5) fixes the heat pipe (2) to the second-level cold head (15); The heat pipe (2) is fixedly connected to the cylinder housing (10), and the heater (3) is fixedly connected to the heat pipe (2).

4. A fast regenerating cryopump according to claim 1, characterized in that: The shell of the heat pipe (2) is made of aluminum, copper, aluminum alloy or copper alloy; a capillary structure is fixed inside the shell of the heat pipe (2); and the heat pipe (2) is filled with a working fluid.

5. A fast regenerating cryopump according to claim 2, characterized in that: It also comprises a heat insulating sleeve (8), wherein the heat insulating sleeve (8) is sleeved on the portion of the heat pipe (2) extending out of the cryopump body (1) and the outside of the heater (3).

6. A fast regenerating cryopump according to claim 5, characterized in that: It also includes a heat insulation layer (6), the heat insulation layer (6) covers the portion of the heat pipe (2) extending out of the cryopump body (1) and the surface of the heater (3), the heat insulation layer (6) is in contact with the cylinder housing (10), and the heat insulation sleeve (8) is located outside the heat insulation layer (6).

7. A fast regenerating cryopump according to claim 5, characterized in that: The thermal insulation sleeve (8) is a hard outer shell, the thermal insulation sleeve (8) is fixedly connected to the cylinder shell (10), the thermal insulation sleeve (8) is not in contact with the heat pipe (2) and the heater (3), and a vacuum environment is formed inside the thermal insulation sleeve (8).

8. A fast regenerating cryopump according to claim 7, characterized in that: It also comprises a radiator (9), an air extraction valve (81) and a vent valve (82); the heat insulation sleeve (8) is fixedly connected to the air extraction valve (81) and the vent valve (82), respectively; the interior of the heat insulation sleeve (8) is connected to the air extraction valve (81) and the vent valve (82), respectively; the air extraction valve (81) is connected to a vacuum pump; and the radiator (9) is in contact with the heat pipe (2).

9. A fast regenerating cryopump according to claim 8, characterized in that: The heat sink (9) comprises a base (91) and fins (82); the base (91) is attached to and fixedly connected to the flat plate portion (21); and the fins (82) and the base (91) are integrally formed.

10. The fast regenerating cryopump according to claim 8, characterized in that: It also comprises a fan (83), the heat insulation sleeve (8) being fixedly connected to the two ventilation valves (82) respectively, and the outer side of at least one ventilation valve (82) being fixedly connected to and in communication with the fan (83).

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