Search

CN-119267146-B - Cryogenic pump for phase-change heating regeneration

CN119267146BCN 119267146 BCN119267146 BCN 119267146BCN-119267146-B

Abstract

The invention relates to a phase-change heating regeneration cryogenic pump, which comprises a cryogenic pump body, a heat pipe, a heater and a heat insulation sleeve, wherein the heat pipe is sequentially contacted with a primary cold head and a secondary cold head inside the cryogenic pump body from top to bottom and penetrates through a cylinder shell of the cryogenic pump body, the heat pipe is continuously lowered from top to bottom, the heater is positioned outside the cryogenic pump body and is contacted with the heat pipe, and the heat insulation sleeve is sleeved outside the heat pipe and the heater. The ice crystals in the heat pipe move in the heat pipe by gravity, so that the working fluid in the heat pipe can still conduct phase change heat conduction after solidification, the heat conduction efficiency of the heat pipe is greatly improved, and the heat conduction is conducted by the heat pipe, so that the heater is positioned at the outer side of the low-temperature pump body, the heater with larger area and power can be arranged, the heat quantity of a cold head in unit time is increased, the regeneration time is shortened, and the production efficiency is improved.

Inventors

  • CUI HANBO
  • WANG ZHANJIE

Assignees

  • 上海优尊真空设备有限公司

Dates

Publication Date
20260508
Application Date
20241203

Claims (8)

  1. 1. The phase-change heating regeneration low-temperature pump comprises a low-temperature pump body (1) and is characterized by further comprising a heat pipe (2), a heater (3) and a heat insulation sleeve (8), wherein the heat pipe (2) is sequentially contacted with a primary cold head (14) and a secondary cold head (15) inside the low-temperature pump body (1) from top to bottom and penetrates through a cylinder shell (10) of the low-temperature pump body (1), the heat pipe (2) continuously descends from top to bottom in height, the heater (3) is positioned outside the low-temperature pump body (1) and is contacted with the heat pipe (2), and the heat insulation sleeve (8) is sleeved outside the heat pipe (2) and the heater (3); the heat pipe (2) comprises a pipe body (20), two ends of the pipe body (20) are closed, working fluid is filled in the pipe body (20), and the pipe body (20) penetrates through the air cylinder shell (10) and is fixedly connected with the air cylinder shell (10); the heat pipe (2) comprises a non-stick coating (22), the non-stick coating (22) is positioned on the inner side of the pipe body (20) and is attached to the inner wall of the pipe body (20), and the non-stick coating (22) is fixedly connected with the pipe body (20); during operation, the working fluid in the heat pipe (2) is solidified into ice crystals due to the fact that the temperature of the cryopump body (1) is too low.
  2. 2. The phase-change heat regeneration cryopump of claim 1, wherein the tube (20) is aluminum, copper, an aluminum alloy or a copper alloy, and the non-stick coating (22) is a polytetrafluoroethylene coating.
  3. 3. A phase change heat regenerated cryopump as claimed in claim 1 wherein the working fluid within the tube (20) has a melting point below-100 ℃ and a critical temperature above 0 ℃.
  4. 4. A phase-change heat regenerated cryopump as claimed in claim 3 wherein the working fluid is ethanol, R23, ‌ R508B or R600a.
  5. 5. The phase-change heating regenerated cryopump of claim 1, wherein a flat plate portion (21) is formed at a portion of the heat pipe (2) extending out of the cryopump body (1), the heater (3) is in contact with and fixedly connected with the flat plate portion (21), and the heater (3) is an electric heater.
  6. 6. The phase-change heating regenerated cryopump of claim 1, wherein the heat insulation sleeve (8) is a hard shell, the heat insulation sleeve (8) is fixedly connected with the cylinder shell (10), the heat insulation sleeve (8) is not contacted with the heat pipe (2) and the heater (3), and a vacuum environment is formed inside the heat insulation sleeve (8).
  7. 7. The phase-change heating regeneration cryopump of claim 1, wherein the included angle between the heat pipe (2) and the horizontal plane is greater than 45 degrees.
  8. 8. A phase change heat regenerated cryopump according to claim 1 further comprising a first fixing means (4) and a second fixing means (5), the first fixing means (4) fixing the heat pipe (2) to the primary cold head (14) and the second fixing means (5) fixing the heat pipe (2) to the secondary cold head (15).

Description

Cryogenic pump for phase-change heating regeneration Technical Field The invention relates to the field of cryopumps, in particular to a phase-change heating regeneration cryopump. Background The working temperature of the existing heat pipe cannot be lower than the condensation point of the working fluid in the heat pipe, otherwise, the working fluid is solidified and cannot reach the heat absorption section through capillary action, so that the working fluid in the heat pipe stops changing phase, and the heat conduction efficiency of the heat pipe is greatly reduced. The cryogenic pump is a storage type vacuum pump, an extremely low temperature surface is arranged in the pump, and gas can be captured through condensation and adsorption, so that the ultra-high vacuum state is realized. The cryopump can obtain clean vacuum with the maximum pumping rate and the lowest limiting pressure, and is widely applied to research and production of semiconductors and integrated circuits, molecular beam research, vacuum coating equipment, vacuum surface analysis instruments, ion implanters, space simulation devices and the like. When the low-temperature pump runs for a long time to reach the saturated capacity, the pumping speed is rapidly reduced, and then the pump is stopped to heat, so that the gas adsorbed on the low-temperature plate is released, and the original pumping performance is recovered. The temperature is raised and the condensed adsorbed gas is released by pumping with a pre-pump, which is called "regeneration". Regeneration is accomplished in several ways: ① The natural heating method is to turn off the power supply of the refrigerator and to heat the low temperature pump slowly with the heat of the pump wall. The temperature rise is slow at the beginning, and when the pressure in the pump rises to the effect of convection heat exchange, the temperature rise rate is accelerated, and finally, the stable temperature rise value is reached. ② The air release heating method is to open the air release valve to put clean and dry air into the air release valve after the refrigerator is stopped to make the low temperature plate of the low temperature pump heat up rapidly ③ The electric heating method is to install electric heater on the first and the second cold heads of the low temperature pump to raise the temperature of the low temperature board fast and shorten the regeneration time. The existing electric heating mode adopts a metal shell to penetrate into the low-temperature pump, a plurality of heating wires and silica gel are arranged in the empty metal shell, the silica gel is positioned between the heating wires and the metal shell, and the heating wires are prevented from contacting each other or the metal shell, so that short circuit is prevented. The smaller the thickness of the silica gel is, the better the heat conducting performance is, but the more short circuit is easy to occur to the electric heating rod, so that electromagnetic interference is caused, and the larger the thickness of the silica gel is, the less short circuit is easy to occur, but the worse the heat conducting performance is. Because the thermal conductivity of silica gel is relatively poor, and the thickness of silica gel in the existing electric heating rod is relatively large, the heating capacity of the electric heating rod to the cold head cannot be continuously improved, and the time for electric heating regeneration is relatively long. And the heating amount cannot be increased by increasing the number of heating rods due to the priority of the internal space of the cryopump and the need to reduce the number of sealing interfaces. Disclosure of Invention The invention provides a phase-change heating regeneration cryopump, which solves the technical problems. The utility model provides a cryogenic pump of phase transition heating regeneration, includes the cryogenic pump body, still includes heat pipe, heater and insulating sheath, the heat pipe from the top down in proper order with the inside one-level cold head of cryogenic pump body and second grade cold head contact and pass the cylinder casing of cryogenic pump body, the heat pipe from the top down highly constantly descends, the heater is located the cryogenic pump body outside and contacts with the heat pipe, the insulating sheath suit is in the heat pipe and heater outside. Further, the heat pipe comprises a pipe body, two ends of the pipe body are closed, working fluid is filled in the pipe body, and the pipe body penetrates through the air cylinder shell and is fixedly connected with the air cylinder shell. Further, the heat pipe comprises a non-stick coating, wherein the non-stick coating is positioned on the inner side of the pipe body and is attached to the inner wall of the pipe body, and the non-stick coating is fixedly connected with the pipe body. Further, the pipe body is made of aluminum, copper, aluminum alloy or copper alloy, and the non-stick coating