Low-temperature pump regeneration heating device

Abstract

The utility model relates to a cryogenic pump regenerative heating device, which comprises a heat pipe, a heater and a heat insulation sleeve, the heat pipe penetrates through a cryogenic pump, the heat pipe is contacted with a primary cold head and a secondary cold head in the cryogenic pump, the heater is positioned outside the cryogenic pump and is contacted with the heat pipe, the heat pipe and the heater are positioned in an inner cavity in the heat insulation sleeve, and the heat insulation sleeve is sleeved on the heat pipe. The inner cavity is in a vacuum environment. The heat pipe is used for conducting heat, the heater is located on the outer side of the low-temperature pump, and therefore the heater with larger area and power can be arranged, heat supplied to the cold head in unit time is increased, regeneration time is shortened, and production efficiency is improved. A vacuum environment is generated on the outer sides of the heat pipe and the heater through the heat insulation sleeve, and heat exchange between the heat pipe and the outside is reduced to the maximum extent when the low-temperature pump adsorbs and heats at low temperature.

Description

Technical Field

[0001] The utility model relates to the field of cryogenic pumps, in particular to a regenerative heating device for a cryogenic pump. Background Art

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

[0003] When a cryopump reaches saturation capacity after long-term operation, its pumping speed drops dramatically. At this point, the pump needs to be stopped and heated to release the gas adsorbed on the cryopanel, restoring its original pumping performance. Heating the temperature and using a pre-pump to remove the condensed and adsorbed gas is called "regeneration."

[0004] There are several ways to regenerate:

[0005] 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 rise is very slow at the beginning. When the pressure in the pump rises to the point where convection heat transfer takes effect, the temperature rise rate accelerates and finally reaches a stable temperature value.

[0006] 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

[0007] 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, thus shortening the regeneration time.

[0008] The existing electric heating method uses an electric heating rod with a metal shell that penetrates into the interior of 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 short circuits.

[0009] The thinner the silicone, the better the thermal conductivity, but the heater rod is more susceptible to short circuits. The thicker the silicone, the less likely it is to short, but the thermal conductivity deteriorates. Because silicone's poor thermal conductivity and the thickness of the silicone in existing heater rods are large, the heater rod's ability to heat the cold head cannot be further increased, and the regeneration time required for electric heating is prolonged. Furthermore, due to the limited space within the cryopump and the need to minimize the number of sealing interfaces, increasing the heating capacity by simply adding heater rods is not an option. Utility Model Content

[0010] The utility model provides a low-temperature pump regeneration heating device, which solves the above technical problems.

[0011] A cryopump regenerative heating device includes a heat pipe, a heater, and an insulation sleeve. The heat pipe passes through the cryopump and contacts the primary and secondary cold heads inside the cryopump. The heater is located outside the cryopump and contacts the heat pipe. The heat pipe and heater are located in an inner cavity inside the insulation sleeve, and the inner cavity is a vacuum environment.

[0012] Furthermore, a portion of the heat pipe extending out of the cryopump is formed with a flat plate portion, the heater is in contact with the flat plate portion, and the heater is an electric heater.

[0013] Furthermore, it also includes a first fixing device and a second fixing device, 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.

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

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

[0016] Furthermore, the melting point of the working fluid in the heat pipe is lower than -100°C and the critical temperature is higher than 0°C.

[0017] Furthermore, the working fluid is ethanol, R23, ‌R508B or R600a.

[0018] Furthermore, the heat pipe passes through the thermal insulation sleeve.

[0019] Furthermore, it also includes an adhesive layer, which is located on the outside of the heat pipe and contacts the thermal insulation sleeve and the cylinder shell respectively to bond and fix the thermal insulation sleeve and the cylinder shell.

[0020] Furthermore, the thermal insulation sleeve is made of plastic, and the thermal insulation sleeve is fixed to the heat pipe by welding.

[0021] The utility model has the following advantages:

[0022] 1. Heat conduction through heat pipes allows the heater to be located outside the cryopump, allowing for the installation of a heater with a larger area and power, increasing the amount of heat supplied to the cold head per unit time, reducing regeneration time, and improving production efficiency;

[0023] 2. The heater is located outside the cryopump, and there is sufficient space between the heater and the heat pipe for insulation treatment, which avoids the short circuit of the heating rod in the existing technology affecting the normal operation of the cryopump and improves the reliability of the cryopump;

[0024] 3. A thermal insulation sleeve is used to create a vacuum environment outside the heat pipe and heater, which minimizes the heat exchange between the heat pipe and the outside world when the heat pipe is adsorbed at low temperature and heated by the cryopump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other implementation drawings can be derived from the provided drawings without inventive effort.

[0026] Figure 1 : Schematic diagram of the three-dimensional structure of the cryopump;

[0027] Figure 2 : Schematic diagram of the three-dimensional structure of the cryopump with some components removed;

[0028] Figure 3 : Schematic diagram of the cross-sectional structure of the cryopump;

[0029] Figure 4 :exist Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle;

[0030] Figure 5 : A cross-sectional view of the heating device;

[0031] Figure 6 : The second cross-sectional view of the heating device. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the accompanying drawings and examples:

[0033] The following describes in detail embodiments of the present invention. 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0034] In the description of this utility model, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0035] 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", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 cannot be understood as a limitation on the present invention.

[0036] Example 1:

[0037] like Figures 1 to 6 As shown, this embodiment provides a cryopump regenerative heating device, including a heat pipe 2, a heater 3, and a thermal insulation sleeve 8. The heat pipe 2 passes through the cryopump 1 and contacts the primary cold head 14 and the secondary cold head 15 inside the cryopump 1. The heater 3 is located outside the cryopump 1 and contacts the heat pipe 2. The heat pipe 2 and heater 3 are located in an inner cavity 80 inside the thermal insulation sleeve 8, which is a vacuum environment. The vacuum environment inside the thermal insulation sleeve 8 serves to isolate heat and reduce heat transfer.

[0038] Preferably, a heat pipe 2 is used to contact the primary cold head 14 and the secondary cold head 15 of the cryopump 1 at the same time, such as Figure 2 and Figure 3 shown.

[0039] Furthermore, the portion of the heat pipe 2 extending from the cryopump 1 is formed with a flat plate portion 21, with which the heater 3, which is an electric heater, contacts. The increased surface area of ​​the flat plate portion 21 increases the contact area with the heater 3. The flat plate portion 21 conducts a greater amount of heat per unit time, allowing the heater 3 to utilize a higher heating power.

[0040] 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.

[0041] Optionally, a first fixing device 4 and a second fixing device 5 are further included, 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 .

[0042] 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 tightens the cold head and the heat pipe 2 inside it so that they are in contact with each other.

[0043] 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 .

[0044] Furthermore, the heat pipe 2 is fixedly connected to the cylinder housing 10 or the cold head base 16 of the cryopump 1, and the heater 3 is fixedly connected to the heat pipe 2. The heat pipe 2 and the cylinder housing 10 or the cold head base 16 are sealed.

[0045] Preferably, the heat pipe 2 is fixed to the cylinder housing 10 or the cold head base 16 of the cryopump 1 by welding.

[0046] Furthermore, the shell of the heat pipe 2 is made of aluminum, copper, aluminum alloy or copper alloy, and a capillary structure is fixed in the shell of the heat pipe 2. The heat pipe 2 is filled with a working fluid. The capillary structure is a conventional technology, such as a sintered structure, a groove, etc., which uses capillary phenomenon to move the liquid.

[0047] 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.

[0048] 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.).

[0049] In one embodiment, if Figure 5 As shown, the heat pipe 2 passes through the thermal insulation sleeve 8 .

[0050] Furthermore, it includes an adhesive layer 84, which is located outside the heat pipe 2 and contacts the thermal insulation sleeve 8 and the cylinder housing 10 respectively to bond and fix the thermal insulation sleeve 8 and the cylinder housing 10. Preferably, the adhesive layer 84 is a sealant or epoxy resin glue.

[0051] Optionally, the thermal insulation sleeve 8 is made of plastic and is welded to the heat pipe 2. The thermal insulation sleeve 8 made of plastic has a low thermal conductivity and the heat transfer when in contact with the heat pipe 2 is small. Ultrasonic welding can be used for welding plastic.

[0052] Optionally, the thermal insulation sleeve 8 and the heat pipe 2 are fixed and sealed by adhesive.

[0053] During installation, after passing through the cylinder housing 10, glue is used to bond the heat pipe 2, the insulation sleeve 8, and the cylinder housing 10. The solidified glue forms an adhesive layer 84, which not only seals the heat pipe 2 but also insulates the portion of the heat pipe 2 exposed between the insulation sleeve 8 and the cylinder housing 10 due to its low thermal conductivity.

[0054] During installation of this embodiment, the fixing method between the cylinder housing 10 and the thermal insulation sleeve 8 is simple; and the vacuuming of the inner cavity 80 is performed in the production link before installation, which has low requirements on the equipment and operation of the installer.

[0055] The electric wires of the heater 3 can pass through between the thermal insulation sleeve 8 and the heat pipe 2 .

[0056] In one embodiment, if Figure 6 As shown, the heat insulating sleeve 8 is fixed to the cylinder housing 10 by welding.

[0057] In this embodiment, the heat insulating sleeve 8 can be made of metal. The air tightness and firmness of the connection between the heat insulating sleeve 8 and the cylinder housing 10 are better, but the vacuuming and welding have higher requirements on the installer.

[0058] Working principle:

[0059] The cryopump 1 cools down internally, allowing the cold shield 12 and cold umbrella 13 to adsorb gas molecules at low temperatures. During operation, the working fluid within the heat pipe 2 solidifies due to the low temperature of the cryopump 1, halting its phase transition. At this point, the heat pipe 2 exchanges heat with the outside world only through conduction, significantly reducing its thermal efficiency. This minimizes the impact of the external temperature on the cryopump 1, allowing the interior of the cryopump 1 to cool smoothly to the desired temperature.

[0060] During regeneration, heater 3 heats flat plate 21. This heat is then conducted along the metal heat pipe 2 to the contact points between the heat pipe 2 and the primary and secondary cold heads 14, 15, melting the solidified working fluid within the heat pipe 2. Once the working fluid melts, the heat pipe 2 undergoes a smooth phase change and conducts heat, significantly improving thermal conductivity. This allows a large amount of heat to be transferred to the primary and secondary cold heads 14, 15 in a short period of time, rapidly heating them and shortening regeneration time. Subsequently, heater 3 stops operating when a specified temperature is reached, as detected by the temperature sensor within cryopump 1.

[0061] The thermal conductivity of metal increases at low temperatures, which is beneficial for the heat pipe 2 to quickly melt the solidified working fluid.

[0062] The cryopump 1 is a prior art cryopump, such as the cryopump disclosed in Chinese Utility Model Patent No. CN117489563B. The primary and secondary cold heads 14, 15 of the cryopump 1 are located within the cylinder housing 10 and outer housing 11, respectively, which are fixedly connected. The cold shield 2 and cold umbrella 3 of the cryopump body 1 are disposed within the outer housing 11, with the end of the cylinder housing 10 secured to the base via a cold head base 16.

[0063] It should be noted that the heating device can directly replace the electric heating rod in the existing cryopump 1. The heat pipe 2 can extend through a hole punched in the cylinder housing 10, or through an existing hole in the cold head base 16 of the cryopump 1. The point where the heat pipe 2 passes through needs to be sealed.

[0064] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments. Any changes or modifications based on the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A cryopump regenerative heating device, characterized in that: The invention comprises a heat pipe (2), a heater (3) and an insulation sleeve (8), wherein the heat pipe (2) passes through a cryogenic pump (1), and the heat pipe (2) contacts a first-stage cold head (14) and a second-stage cold head (15) inside the cryogenic pump (1), and the heater (3) is located outside the cryogenic pump (1) and contacts the heat pipe (2), and the heat pipe (2) and the heater (3) are located in an inner cavity (80) inside the insulation sleeve (8), and the inner cavity (80) is a vacuum environment.

2. The cryopump regenerative heating device according to claim 1, characterized in that: The portion of the heat pipe (2) extending from the cryopump (1) is formed with 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.

3. The cryopump regenerative heating device 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-level cold head (14), and the second fixing device (5) fixes the heat pipe (2) to the second-level cold head (15).

4. The cryopump regenerative heating device according to claim 1, characterized in that: The heat pipe (2) passes through the cylinder housing (10) and is fixedly connected to the cylinder housing (10), and the heater (3) is fixedly connected to the heat pipe (2).

5. The cryopump regenerative heating device 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 provided inside the shell of the heat pipe (2); and the heat pipe (2) is filled with a working fluid.

6. The cryopump regenerative heating device according to claim 5, characterized in that: The working fluid in the heat pipe (2) has a melting point lower than -100°C and a critical temperature higher than 0°C.

7. The cryopump regenerative heating device according to claim 6, characterized in that: The working fluid is ethanol, R23, R508B or R600a.

8. The cryopump regenerative heating device according to any one of claims 1 to 7, characterized in that: The heat pipe (2) passes through the heat insulation sleeve (8).

9. The cryopump regenerative heating device according to claim 8, characterized in that: It also includes an adhesive layer (84), which is located outside the heat pipe (2). The adhesive layer (84) contacts the thermal insulation sleeve (8) and the cylinder shell (10) respectively and adheres and fixes the thermal insulation sleeve (8) and the cylinder shell (10).

10. The cryopump regenerative heating device according to claim 8, characterized in that: The thermal insulation sleeve (8) is made of plastic, and the thermal insulation sleeve (8) is fixed to the heat pipe (2) by welding.

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