A fast regenerative cryopump

Abstract

The application relates to a quick-regeneration cryogenic pump, which comprises a cryogenic pump body, a heat pipe and a heater, the heat pipe passes through a cylinder shell of the cryogenic pump body, the heat pipe is in contact with a primary cold head and a secondary cold head inside the cryogenic pump body, and the heater is located outside the cryogenic pump body and in contact with the heat pipe. The application realizes heat conduction through the heat pipe, the heater is located outside the cryogenic pump body, a heater with a larger area and power can be arranged, the heat quantity supplied to the cold head per unit time is increased, the regeneration time is reduced, and the production efficiency is improved; the heater is located outside the cryogenic pump body, there is enough space between the heater and the heat pipe for insulation treatment, and the short circuit of the heating rod in the prior art does not affect the normal work of the cryogenic pump.

Description

Technical Field

[0001] This invention relates to the field of cryogenic pumps, and in particular to a cryogenic pump with rapid regeneration. Background Technology

[0002] Cryogenic pumps are storage-type vacuum pumps. They contain an extremely low-temperature surface that captures gases through condensation and adsorption to achieve ultra-high vacuum. Cryogenic pumps can obtain clean vacuums with the highest pumping rates and lowest ultimate pressures, and are widely used in semiconductor and integrated circuit research and production, as well as in molecular beam research, vacuum coating equipment, vacuum surface analysis instruments, ion implanters, and space simulation devices.

[0003] When a cryogenic pump reaches its saturation capacity after long-term operation, its pumping speed drops sharply. At this point, it is necessary to stop the pump and raise the temperature to release the gas adsorbed on the cryogenic plate and restore its original pumping performance. The process of raising the temperature and using a pre-pump to remove the released condensed and adsorbed gas is called "regeneration".

[0004] Regeneration can be achieved in the following ways:

[0005] ① Natural heating method: Turn off the power to the refrigeration unit and use the heat from the pump wall to slowly heat up the cryogenic pump. The heating is very slow at first, but when the pressure inside the pump rises to the point where convection heat transfer takes effect, the heating rate accelerates and eventually reaches a stable temperature.

[0006] ② Venting and Heating Method: After shutting down the refrigeration unit, open the vent valve to release clean, dry air, causing the low-temperature pump's low-temperature plate to heat up rapidly.

[0007] ③ Electric heating method: Electric heaters are installed on the primary and secondary cold heads of the cryogenic pump. During regeneration, the low-temperature plate is heated by electricity to quickly raise the temperature and shorten the regeneration time.

[0008] The existing electric heating method uses an electric heating rod with a metal shell inserted into the cryogenic pump. 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, thus preventing short circuits.

[0009] Thinner silicone rubber has better thermal conductivity, but it also makes the heating element more prone to short circuits, leading to electromagnetic interference. Conversely, thicker silicone rubber reduces the likelihood of short circuits, but reduces thermal conductivity. Because of the poor thermal conductivity of silicone rubber, and the relatively thick silicone rubber layer in existing heating elements, the heating output of the heating element to the cold head cannot be further increased, resulting in longer regeneration times. Furthermore, the need for limited internal space in cryogenic pumps and a reduction in the number of sealing interfaces prevents increasing the number of heating elements from increasing the heating output. Summary of the Invention

[0010] This invention provides a cryogenic pump with rapid regeneration, which solves the above-mentioned technical problems.

[0011] A rapid regeneration cryogenic pump includes a cryogenic pump body, a heat pipe, and a heater. The heat pipe passes through the cylinder housing of the cryogenic pump body and contacts a primary cold head and a secondary cold head inside the cryogenic pump body. The heater is located outside the cryogenic pump body and contacts the heat pipe.

[0012] Furthermore, the portion of the heat pipe extending out of the cryogenic pump body has a flat plate portion, and the heater contacts the flat plate portion; the heater is an electric heater.

[0013] 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-stage cold head, and the second fixing device fixes the heat pipe to the second-stage cold head;

[0014] The heat pipe is fixedly connected to the cylinder housing, and the heater is fixedly connected to the heat pipe.

[0015] Furthermore, the heat pipe housing is made of aluminum, copper, aluminum alloy, or copper alloy, a capillary structure is fixed inside the heat pipe housing, and the heat pipe is filled with a working fluid.

[0016] Furthermore, it also includes a heat insulation sleeve, which is fitted onto the portion of the heat pipe extending out of the cryogenic pump body and the outside of the heater.

[0017] Furthermore, it also includes a heat insulation layer that covers the portion of the heat pipe extending out of the cryogenic pump body and the surface of the heater. The heat insulation layer is in contact with the cylinder housing, and the heat insulation sleeve is located outside the heat insulation layer.

[0018] Furthermore, the heat insulation sleeve is a rigid outer shell, the heat insulation sleeve is fixedly connected to the cylinder housing, the heat insulation sleeve does not contact the heat pipe and heater, and a vacuum environment is formed inside the heat insulation sleeve.

[0019] Furthermore, it also includes a radiator, an extraction valve, and a venting valve. The heat insulation sleeve is fixedly connected to the extraction valve and the venting valve respectively. The interior of the heat insulation sleeve is connected to the extraction valve and the venting valve respectively. The extraction valve is connected to a vacuum pump. The radiator is in contact with a heat pipe.

[0020] Furthermore, the heat sink includes a base and fins, the base is attached to and fixedly connected to the flat plate, and the fins are integrally formed with the base.

[0021] Furthermore, it also includes a fan, and the heat insulation sleeve is fixedly connected to two vent valves respectively, and at least one vent valve is fixedly connected to and communicates with the fan on its outer side.

[0022] The present invention has the following advantages:

[0023] 1. By conducting heat through heat pipes, the heater is located outside the cryogenic pump body, which allows for the installation of a heater with a larger area and power, increasing the heat delivered to the cold head per unit time, reducing regeneration time, and improving production efficiency;

[0024] 2. The heater is located outside the cryogenic pump body, and there is sufficient space between the heater and the heat pipe for insulation, which avoids the short circuit of the heating rod in the existing technology from affecting the normal operation of the cryogenic pump and improves the reliability of the cryogenic pump.

[0025] 3. The use of a heat insulation jacket to insulate the heat pipe and heater reduces the heat exchange between the heat pipe and the outside environment during the low-temperature adsorption and heating of the low-temperature pump.

[0026] 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;

[0027] 5. A thick insulation layer can be used between the heat pipe and the heater, or the heater can be equipped with an insulating shell. The heat pipe is not energized, thus avoiding electromagnetic interference to the pump's internal and external equipment caused by short circuits in existing technologies. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0029] Figure 1 : A three-dimensional structural diagram of the cryogenic pump body;

[0030] Figure 2 : A three-dimensional structural diagram of the present invention with some components removed;

[0031] Figure 3 : A cross-sectional view of the present invention;

[0032] Figure 4 :exist Figure 3 Schematic diagram of the cross-sectional structure at point AA;

[0033] Figure 5 Cross-sectional view of the heating device in Example 2;

[0034] Figure 6 Cross-sectional view of the heating device in Embodiment 3;

[0035] Figure 7 Cross-sectional view of the heating device in Example 4;

[0036] Figure 8 :exist Figure 7 Sectional view at point BB. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and examples:

[0038] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] Example 1:

[0042] like Figures 1 to 4 As shown, this embodiment provides a rapid regeneration cryogenic pump, including a cryogenic pump body 1, a heat pipe 2, and a heater 3. The heat pipe 2 passes through the cylinder housing 10 of the cryogenic pump body 1. 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 is in contact with the heat pipe 2.

[0043] Optionally, a single heat pipe 2 can be used to contact both the primary cold head 14 and the secondary cold head 15 simultaneously, such as... Figure 2 and Figure 3 As shown.

[0044] Optionally, multiple heat pipes 2 are used, with each heat pipe 2 contacting only one of the primary cold head 14 and the secondary cold head 15, as shown in the figure.

[0045] Furthermore, the portion of the heat pipe 2 extending out of the cryogenic pump body 1 forms a flat plate portion 21, and the heater 3 is in contact with the flat plate portion 21. 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 thermal conductivity per unit time, allowing the heater 3 to employ a higher heating power.

[0046] Optionally, the heat pipe 2 is brazed to the primary cold head 14, and the heat pipe 2 is brazed to the secondary cold head 15.

[0047] Optionally, it also 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.

[0048] Preferably, such as Figure 2 and Figure 3 As shown, the first fixing device 4 and the second fixing device 5 can be either fixing blocks or clamps. The fixing block is fixedly connected to the cold head by screws; the clamp tightens the internal cold head and heat pipe 2, bringing them into contact.

[0049] Preferably, the tiny gaps on the surface between the heat pipe 2 and the first fixing device 4 and the second fixing device 5 are filled with thermally conductive materials such as silicone grease.

[0050] 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. A seal is used between the heat pipe 2 and the cylinder housing 10.

[0051] Preferably, the heat pipe 2 is welded and fixed to the cylinder housing 10.

[0052] Furthermore, the shell of the heat pipe 2 is made of aluminum, copper, aluminum alloy, or copper alloy, and a capillary structure is fixed inside the shell of the heat pipe 2. The heat pipe 2 is filled with a working fluid. The capillary structure is a prior art technique, such as sintered structures or grooves, which utilize capillary phenomena to move the liquid.

[0053] Preferably, the working fluid inside the heat pipe 2 has a melting point below -100°C and a critical temperature above 0°C.

[0054] 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.).

[0055] During operation, the internal temperature of the cryogenic pump body 1 decreases, allowing the cold shield 12 and cold umbrella 13 to adsorb molecules in the gas at low temperatures. During operation, due to the extremely low temperature of the cryogenic pump body 1, the working fluid inside the heat pipe 2 solidifies, and the phase change stops. At this time, the heat pipe 2 exchanges heat with the outside environment only through heat conduction, greatly reducing the thermal conductivity and minimizing the impact of the external temperature on the internal temperature of the cryogenic pump body 1, allowing the internal temperature of the cryogenic pump body 1 to be smoothly reduced to the specified temperature.

[0056] During regeneration, heater 3 heats the flat plate section 21. The heat is conducted along the metal heat pipe 2 to the contact points between the heat pipe 2 and the primary and secondary cold heads 14 and 15, melting the solidified working fluid inside the heat pipe 2. After the working fluid melts, the heat pipe 2 can smoothly undergo a phase change for heat conduction, greatly improving its thermal efficiency. This allows a large amount of heat to be transferred to the primary and secondary cold heads 14 and 15 in a short time, rapidly raising their temperature and shortening the regeneration time. Afterward, based on the temperature sensor inside the cryogenic pump body 1, heater 3 stops operating once the designated temperature is reached.

[0057] Among them, the thermal conductivity of metal increases at low temperatures, which is beneficial for heat pipe 2 to quickly melt the solidified working fluid.

[0058] It should be noted that the cryogenic pump body 1 is a cryogenic pump of the prior art, such as the cryogenic pump disclosed in Chinese invention patent with authorization announcement number CN117489563B. The primary cold head 14 and the secondary cold head 15 of the cryogenic pump body 1 are located inside the cylinder housing 10 and the outer housing 11, respectively, and the cylinder housing 10 and the outer housing 11 are fixedly connected. The cold shield 2 and the cold umbrella 3 of the cryogenic pump body 1 are disposed inside the outer housing 11, and the end of the cylinder housing 10 is fixed to the base through the cold head base 16.

[0059] Example 2:

[0060] like Figures 1 to 5 As shown, this embodiment is a further improvement on the basis of embodiment one, and also includes a heat insulation sleeve 8, which is fitted on the part of the heat pipe 2 that extends out of the cryogenic pump body 1 and the outside of the heater 3.

[0061] Furthermore, it also includes a heat insulation layer 6, which covers the portion of the heat pipe 2 extending out of the cryogenic pump 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, reducing heat transfer.

[0062] Optionally, the heat insulation layer 6 is made of silicone. The silicone adheres to the part of the heat pipe 2 that extends out of the cryogenic pump body 1 and the heater 3. The end of the silicone is bonded and fixed to the outer side of the cylinder housing 10, so that the inside of the heat insulation layer 6 is sealed from the outside.

[0063] Optionally, the insulation layer 6 is an insulation coating, which is applied by spraying a coating onto a portion of the cryogenic pump body 1 and the surface of the heater 3 to achieve insulation.

[0064] Furthermore, the end of the heat insulation sleeve 8 is fixed and sealed to the cylinder housing 10, and the heat insulation sleeve 8 is elastic.

[0065] Preferably, the heat insulation sleeve 8 is a heat insulation cotton with aluminum foil inside, and the aluminum foil is used to reduce heat radiation.

[0066] During operation, the internal temperature of the cryogenic pump body 1 decreases, and the heat insulation jacket 8 reduces the amount of cooling energy lost from the portion of the heat pipe 2 extending out of the cryogenic pump body 1. During regeneration, the heat insulation jacket 8 reduces the loss of heat generated by the heater 3. Through its insulation effect, the heat insulation jacket 8 reduces energy consumption.

[0067] Example 3:

[0068] like Figures 1 to 4 and Figure 6 As shown, this embodiment is a further improvement on the basis of embodiment one, and also includes a heat insulation sleeve 8, which is fitted on the part of the heat pipe 2 that extends out of the cryogenic pump body 1 and the outside of the heater 3.

[0069] Furthermore, the heat insulation sleeve 8 is a rigid outer shell, the heat insulation sleeve 8 is fixedly connected to the cylinder housing 10, the heat insulation sleeve 8 does not contact the heat pipe 2 and the heater 3, and a vacuum environment is formed inside the heat insulation sleeve 8.

[0070] Preferably, the heat insulation sleeve 8 is welded and fixed to the outside of the cylinder housing 10.

[0071] Preferably, the inner wall of the heat insulation sleeve 8 is plated with silver, and the silver plating is used to reduce heat radiation.

[0072] The inner cavity 80 of the insulation jacket 8 is in a vacuum state, with extremely low thermal conductivity. During operation, the internal temperature of the cryogenic pump body 1 decreases, and the insulation jacket 8 reduces the cooling capacity lost by the portion of the heat pipe 2 extending out of the cryogenic pump body 1; during regeneration, the insulation jacket 8 reduces the loss of heat generated by the heater 3. Through its insulation effect, the insulation jacket 8 reduces energy consumption.

[0073] Example 4:

[0074] like Figures 1 to 4 , Figure 7 and Figure 8 As shown, this embodiment is a further improvement on the basis of embodiment one, and also includes a heat insulation sleeve 8, which is fitted on the part of the heat pipe 2 that extends out of the cryogenic pump body 1 and the outside of the heater 3.

[0075] Further, the heat insulation sleeve 8 is a rigid outer shell, which is fixedly connected to the cylinder housing 10. The heat insulation sleeve 8 does not contact the heat pipe 2 and the heater 3, and a vacuum environment is formed inside the heat insulation sleeve 8.

[0076] Preferably, the heat insulation sleeve 8 is fixedly welded to the outer side of the cylinder housing 10.

[0077] Preferably, the inner wall of the heat insulation sleeve 8 is silver-plated, and the silver plating layer is used to reduce heat radiation.

[0078] Further, it further includes a radiator 9, an air extraction valve 81 and an air vent valve 82. The heat insulation sleeve 8 is fixedly connected to the air extraction valve 81 and the air vent valve 82 respectively. The interior of the heat insulation sleeve 8 is respectively connected to the air extraction valve 81 and the air vent valve 82. The air extraction valve 81 is connected to a vacuum pump, and the radiator 9 contacts the heat pipe 2. Among them, the radiator 9 does not contact the heat insulation sleeve 8.

[0079] Further, the radiator 9 includes a base 91 and fins 82. The base 91 is attached to and fixedly connected to the flat part 21, and the fins 82 are integrally formed with the base 91. The fins 82 are used to increase the heat exchange area.

[0080] Preferably, the radiator 9 is made of aluminum, copper, aluminum alloy or copper alloy.

[0081] Further, it further includes a fan 83. The heat insulation sleeve 8 is fixedly connected to two air vent valves 82 respectively. At least one outer side of the air vent valve 82 is fixedly connected to and communicates with the fan 83.

[0082] Preferably, the fan 83 is an axial flow fan or a centrifugal fan.

[0083] During regeneration, the heater 3 heats the flat part 21, and the heat is conducted along the heat pipe 2 made of metal to the contact points between the heat pipe 2 and the first-stage cold head 14 and the second-stage cold head 15, so that the solidified working fluid in the heat pipe 2 melts.

[0084] After the working fluid melts, the two air vent valves 82 are opened to connect the inner cavity 80 of the heat insulation sleeve 8 with the outside world, and normal-temperature air enters the inside of the heat insulation sleeve 8. At this time, the heater 3 stops working, and the fan 83 works, and the air flow blows through the surface of the fins 82 for heat exchange. By using the heat in the air to heat the first-stage cold head 14 and the second-stage cold head 15, the electric energy consumed by the heater 3 is reduced.

[0085] Before the cryopump body 1 works, the air vent valve 82 and the fan 83 are closed. Then, the air extraction valve 81 is opened. After the vacuum pump evacuates the inner cavity 80, the air extraction valve 81 is closed. Among them, the vacuum pump can be an independent vacuum pump or a fore pump (vacuum pump) supporting the cryopump.

[0086] The present invention has been described above by way of example, but the present invention is not limited to the specific embodiments described above. Any modifications or variations made based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A rapid regeneration cryogenic pump, comprising a cryogenic pump body (1), characterized in that: It also includes a heat pipe (2) and a heater (3), the heat pipe (2) passing through the cylinder housing (10) of the cryogenic pump body (1), the heat pipe (2) contacting the first-stage cold head (14) and the second-stage cold head (15) inside the cryogenic pump body (1), and the heater (3) located outside the cryogenic pump body (1) and in contact with the heat pipe (2). The heat pipe (2) has a capillary structure fixed inside its shell and is filled with working fluid. It also includes a heat insulation sleeve (8), which is fitted on the part of the heat pipe (2) that extends out of the cryogenic pump body (1) and the outside of the heater (3); During operation, the working fluid inside the heat pipe (2) will solidify due to the low temperature of the cryogenic pump body (1).

2. The cryogenic pump with rapid regeneration according to claim 1, characterized in that: The portion of the heat pipe (2) extending out of the cryogenic pump body (1) forms a flat plate (21), and the heater (3) contacts the flat plate (21). The heater (3) is an electric heater.

3. The cryogenic pump with rapid regeneration according to claim 1, characterized in that: It also 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 first-stage cold head (14) and the second fixing device (5) fixes the heat pipe (2) to the second-stage 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. The cryogenic pump with rapid regeneration according to claim 1, characterized in that: The shell of the heat pipe (2) is made of aluminum, copper, aluminum alloy or copper alloy.

5. The cryogenic pump with rapid regeneration according to claim 1, characterized in that: It also includes a heat insulation layer (6) that covers the portion of the heat pipe (2) that extends out of the cryogenic pump 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).

6. The cryogenic pump with rapid regeneration according to claim 1, characterized in that: The heat insulation sleeve (8) is a rigid outer shell. The heat insulation sleeve (8) is fixedly connected to the cylinder housing (10). The heat insulation sleeve (8) does not contact the heat pipe (2) and the heater (3). A vacuum environment is formed inside the heat insulation sleeve (8).

7. A cryogenic pump with rapid regeneration according to claim 6, characterized in that: It also includes a radiator (9), an air extraction valve (81) and a ventilation valve (82). The heat insulation sleeve (8) is fixedly connected to the air extraction valve (81) and the ventilation valve (82) respectively. The inside of the heat insulation sleeve (8) is connected to the air extraction valve (81) and the ventilation valve (82) respectively. The air extraction valve (81) is connected to the vacuum pump. The radiator (9) is in contact with the heat pipe (2).

8. A cryogenic pump with rapid regeneration according to claim 7, characterized in that: The radiator (9) includes a base (91) and fins (82). The base (91) is attached to and fixedly connected to the flat plate (21). The fins (82) are integrally formed with the base (91).

9. A cryogenic pump with rapid regeneration according to claim 7, characterized in that: It also includes a fan (83), and the heat insulation sleeve (8) is fixedly connected to two vent valves (82) respectively. At least one vent valve (82) is fixedly connected to the fan (83) on the outside and in communication.

Images