A multi-refrigerator cryogenic pump

Abstract

The present invention discloses a multi-refrigerator cryogenic pump, comprising a pump casing, a shielding cover being arranged in the pump casing, a condensation adsorption component being arranged in the shielding cover, the cryogenic pump also comprising at least two groups of refrigerators, the refrigerators are all provided with a first cold head and a second cold head, the first cold head is thermally connected to the same shielding cover, and the second cold head is thermally connected to the same condensation adsorption component, by thermally connecting the first cold heads of at least two groups of refrigerators to the same shielding cover, and thermally connecting the second cold heads to the same condensation adsorption component, multiple refrigerators work together to cool the same shielding cover and condensation adsorption component, thereby shortening the cooling time and the regeneration cycle, improving the pumping speed and the air extraction capacity of the cryogenic pump, and meeting the demand for higher pumping speed of large vacuum equipment.

Description

Technical Field

[0001] The invention relates to the technical field of pump bodies, and in particular to a multi-refrigerator cryogenic pump. Background Art

[0002] Cryopumps are devices that use low-temperature surfaces to adsorb gas molecules to achieve a vacuum environment. They reduce the internal temperature to an extremely low level, causing the gas molecules to condense or adsorb when they come into contact with the low-temperature surface, thereby effectively removing these gases from the system. Cryopumps are widely used in vacuum coating, semiconductor etching and ion implantation, high-energy physics, space environment simulation and other fields.

[0003] Traditional cryopumps are usually equipped with a single refrigerator, which cools the cold head of the refrigerator located in the cold umbrella, thereby reducing the temperature inside the pump and ensuring that the required vacuum degree is achieved. However, the performance of the cryopump, such as pumping speed and air extraction capacity, is directly related to the refrigeration power of the refrigerator. For large-caliber cryopumps, traditional refrigerators are limited in power, resulting in limited pumping speed and adsorption capacity of the cryopump, and long cooling and regeneration time, which makes it difficult to meet the needs of some high-end applications for rapid cooling and efficient air extraction. Summary of the invention

[0004] The object of the present invention is to provide a multi-refrigerator cryopump, so as to solve the problem that the pumping speed and adsorption capacity of a large-caliber cryopump are limited and the cooling and regeneration time are long due to the power limitation of the refrigerator.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a multi-refrigerator cryogenic pump, comprising a pump casing, a shielding cover is provided in the pump casing, a condensation adsorption assembly is provided in the shielding cover, the cryogenic pump also includes at least two groups of refrigerators, each of the refrigerators is provided with a first cold head and a second cold head, the first cold head is thermally connected to the same shielding cover, and the second cold head is thermally connected to the same condensation adsorption assembly.

[0006] As a further optimization scheme of the present invention, the condensation adsorption component includes several layers of cold umbrella blades and a heat-conductive support member arranged between adjacent cold umbrella blades. The cold umbrella blades and the heat-conductive support member are both provided with an adsorption layer. The several layers of the cold umbrella blades are divided into upper umbrella pieces, middle umbrella pieces and lower umbrella pieces from top to bottom. The lower umbrella pieces are provided with avoidance openings, and the second cold head can pass through the avoidance opening to connect with the middle umbrella pieces.

[0007] As a further optimization solution of the present invention, a cold umbrella heat conducting sheet is provided between the second cold head and the middle umbrella sheet.

[0008] As a further optimization scheme of the present invention, the heat-conductive support member is a support ring, and the support ring located between the middle umbrella piece and the lower umbrella piece is arranged at the avoidance opening to allow the second cold head to pass through the support ring, and the adsorption layer on the heat-conductive support member includes a plurality of columnar coconut shell activated carbons arranged on the outer wall of the support ring.

[0009] As a further optimization scheme of the present invention, the heat-conducting support member is provided with a plurality of first through holes, and the cold umbrella blades are provided with a plurality of second through holes that can cooperate with the first through holes so as to allow bolts to fix the heat-conducting support member and the cold umbrella blades.

[0010] As a further optimization scheme of the present invention, the adsorption layer on the cold umbrella blades includes block coconut shell activated carbon.

[0011] As a further optimization scheme of the present invention, a first-level baffle is provided in the shielding cover, and the first-level baffle includes a cross-shaped bracket and a plurality of annular shutters arranged on the cross-shaped bracket, and the four ends of the cross-shaped bracket are provided with supporting sleeves, and four baffle pillars for fixing the first-level baffle are provided between the shielding cover and the first-level baffle, one end of the baffle pillar is connected to the bottom of the shielding cover, and the other end of the baffle pillar is connected to the corresponding supporting sleeve, and the condensation adsorption assembly is arranged between the four baffle pillars.

[0012] As a further optimization solution of the present invention, two groups of temperature sensor interfaces, one group of vacuum gauge interfaces, and one group of rough pumping interfaces are provided at the bottom of the pump housing.

[0013] As a further optimization solution of the present invention, the side wall of the shielding cover is provided with an annular protrusion.

[0014] As a further optimization solution of the present invention, a carrying sleeve is provided at the bottom of the pump housing for facilitating carrying using a carrying bracket.

[0015] Compared with the prior art, the present invention has the following advantages: by thermally connecting the first cold heads of at least two groups of refrigerators to the same shielding cover, and thermally connecting the second cold heads to the same condensation adsorption component, multiple refrigerators can work together to cool the same shielding cover and condensation adsorption component, thereby shortening the cooling time and regeneration cycle, improving the pumping speed and suction capacity of the cryogenic pump, and meeting the demand for higher pumping speeds of large vacuum equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a three-dimensional schematic diagram of the present invention;

[0017] Figure 2 It is an explosion schematic diagram of the present invention;

[0018] Figure 3 It is a cross-sectional schematic diagram of the present invention;

[0019] Figure 4 It is a schematic diagram of the structure of the upper umbrella sheet and the adsorption layer in the present invention;

[0020] Figure 5 It is an exploded schematic diagram of the middle-layer parachute sheet and the refrigerator in the present invention;

[0021] Figure 6 It is a schematic diagram of the structure of the lower umbrella sheet and the adsorption layer of the present invention;

[0022] Figure 7 is a three-dimensional schematic diagram of a heat-conducting support member in the present invention;

[0023] Figure 8 It is a three-dimensional schematic diagram of a primary baffle in the present invention;

[0024] Fig. 9 It is a three-dimensional schematic diagram of the pump casing of the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] The present invention discloses a multi-refrigerator cryopump, comprising a pump casing 1, a shielding cover 2 being provided in the pump casing 1, a condensation adsorption assembly 3 being provided in the shielding cover 2, the cryopump further comprising at least two groups of refrigerators 4, each of the refrigerators 4 being provided with a first cold head 41 and a second cold head 42, the first cold head 41 being thermally connected to the same shielding cover 2, and the second cold head 42 being thermally connected to the same condensation adsorption assembly 3.

[0027] The shielding cover 2 is located inside the pump housing 1, and is used to surround the condensation adsorption component 3 to prevent external heat from being conducted to the condensation adsorption area, thereby ensuring the working efficiency of the condensation adsorption component 3. The condensation adsorption component 3 is used to capture gas molecules and condense or adsorb them on the surface, thereby achieving a pumping effect. The refrigeration capacity of the cryopump is increased by setting at least two sets of refrigerators 4. The first cold head 41 is thermally connected to the shielding cover 2 to maintain the working temperature of the shielding cover 2; the second cold head 42 is thermally connected to the condensation adsorption component 3 to maintain the working temperature of the condensation adsorption component 3.

[0028] By thermally connecting the first cold heads 41 of at least two groups of refrigerators 4 to the same shielding cover 2, and thermally connecting the second cold heads 42 to the same condensation adsorption component 3, multiple refrigerators 4 can work together to cool the same shielding cover 2 and condensation adsorption component 3, thereby shortening the cooling time and regeneration cycle, improving the pumping speed and suction capacity of the cryogenic pump, and meeting the demand for higher pumping speeds for large vacuum equipment.

[0029] In one embodiment, the shielding cover 2 is made of red copper and is made by integrated stamping, stretching and spinning processes. The outer surface of the shielding cover 2 is nickel-plated, and the inner surface of the shielding cover 2 is blackened. The bottom of the shielding cover 2 is provided with a plurality of circular openings, and the first cold head 41 is fixed to the corresponding circular openings, thereby completing the fixing between the shielding cover 2 and the refrigerator 4. The first cold head 41 is connected to the shielding cover 2, so that the shielding cover 2 can maintain an operating temperature of about 80K.

[0030] In one embodiment, a shielding cover gasket 22 is provided at the upper part of the connection between the shielding cover 2 and the first cold head 41. The material of the shielding cover gasket 22 is stainless steel, and the outer surface of the shielding cover gasket 22 is nickel-plated. Through the setting of the shielding cover gasket 22, the force at the connection between the shielding cover 2 and the first cold head 41 is uniform.

[0031] In one embodiment, the refrigerator 4 is a GM refrigerator, which has multi-stage cooling capabilities, which helps to optimize thermal management and improve overall efficiency.

[0032] The condensation adsorption component 3 includes a plurality of layers of cold umbrella blades 31 and a heat-conducting support member 32 arranged between adjacent cold umbrella blades 31. The cold umbrella blades 31 and the heat-conducting support member 32 are both provided with an adsorption layer 33. The plurality of layers of the cold umbrella blades 31 are divided into an upper umbrella piece 311, a middle umbrella piece 312, and a lower umbrella piece 313 from top to bottom. The lower umbrella piece 313 is provided with an avoidance opening 3131, and the second cold head 42 can pass through the avoidance opening 3131 to be connected with the middle umbrella piece 312.

[0033] The cooling umbrella blades 31 provide a large surface area for condensation and adsorption of gas molecules. Each layer of cooling umbrella blades 31 is provided with an adsorption layer 33 to effectively capture the passing gas molecules. The avoidance opening 3131 on the lower umbrella blade 313 allows the second cold head 42 to pass through and connect to the middle umbrella blade 312, thereby transferring the cooling effect of the refrigerator to the middle umbrella blade 312, so that the cold energy can be transferred from the middle umbrella blade 312 to the upper umbrella blade 311 and the lower umbrella blade 313, optimizing the cooling path and improving the cooling efficiency.

[0034] In one embodiment, the number of layers of the cold umbrella blades 31 is eight, wherein the number of layers of the upper umbrella pieces 311 is three, the number of layers of the middle umbrella pieces 312 is one, and the number of layers of the lower umbrella pieces 313 is four. The lower surface of the top upper umbrella piece 311, the upper surface of the bottom lower umbrella piece 313, and the upper and lower surfaces of the other cold umbrella blades 31 except the former are provided with an adsorption layer 33.

[0035] A cold umbrella heat conducting sheet 5 is provided between the second cold head 42 and the middle umbrella sheet 312 .

[0036] The cold umbrella heat conducting sheet 5 can enhance the connection strength between the second cold head 42 and the middle umbrella sheet 312, improve the efficiency of cold energy transmission, and make the cold energy more evenly distributed on the entire middle umbrella sheet 312, so that the middle umbrella sheet 312 can reach the working temperature faster, shortening the cooling time.

[0037] The heat-conducting support member 32 is a support ring, and the support ring located between the middle umbrella piece 312 and the lower umbrella piece 313 is arranged at the avoidance opening 3131 to allow the second cold head 42 to pass through the support ring. The adsorption layer 33 on the heat-conducting support member 32 includes a plurality of columnar coconut shell activated carbons 331 arranged on the outer wall of the support ring.

[0038] By setting a hollow support ring between the middle umbrella piece 312 and the lower umbrella piece 313 at the avoidance opening 3131 for the second cold head 42 to pass through the support ring, and setting a columnar coconut shell activated carbon 331 on the outer wall of the support ring, the adsorption area of ​​the condensation adsorption component 3 is increased, thereby enhancing the overall gas capture capability.

[0039] In one embodiment, the adsorption layer 33 on the cooling umbrella blade 31 has a mounting groove 333 for mounting the support ring, which is convenient for fixing the support ring.

[0040] In one embodiment, the width of the hollow portion of the support ring is greater than the width of the avoidance opening 3131, and the adsorption layer 33 on the lower umbrella piece 313 is located at the avoidance opening 3131 and is provided with an opening 334 for the second cold head 42 to pass through, and the adsorption layer 33 has an adsorption portion 335 between the mounting groove 333 and the opening 334, thereby condensing and adsorbing the gas in the support ring.

[0041] The heat-conducting support member 32 is provided with a plurality of first through holes 321 , and the cooling parapet blades 31 are provided with a plurality of second through holes 314 that can cooperate with the first through holes 321 so as to allow bolts to fix the heat-conducting support member 32 and the cooling parapet blades 31 .

[0042] By setting the first through hole 321 and the second through hole 314, bolts can fix the heat-conducting support 32 to the cold umbrella blade 31, thereby realizing full mechanical fixation of the condensation adsorption component 3, facilitating installation and disassembly, and reducing maintenance costs.

[0043] In one embodiment, the upper and lower parts of the heat-conducting support member 32 have bent parts 322, and the first through hole 321 is provided on the bent part 322 to facilitate the nut to fix the bolt. The bent part 322 is bent inward to improve the installation stability.

[0044] The adsorption layer 33 on the cooling umbrella blade 31 includes block coconut shell activated carbon 332 .

[0045] The activated carbon adhered to the cryopanel blades of the conventional cryopump is small-particle columnar coconut shell activated carbon, and there are gaps between the columnar coconut shell activated carbon, resulting in a large waste of the surface area of ​​the cryopanel. The adsorption layer 33 on the cryopanel blade 31 includes a block of coconut shell activated carbon 332, which greatly increases the amount of coconut shell activated carbon adhered, thereby improving the pumping speed and adsorption amount of the cryopump.

[0046] A primary baffle 6 is provided in the shielding cover 2, and the primary baffle 6 includes a cross-shaped bracket 61 and a plurality of annular shutters 62 arranged on the cross-shaped bracket 61. Support sleeves 611 are provided at the four ends of the cross-shaped bracket 61. Four baffle pillars 7 for fixing the primary baffle 6 are provided between the shielding cover 2 and the primary baffle 6. One end of the baffle pillar 7 is connected to the bottom of the shielding cover 2, and the other end of the baffle pillar 7 is connected to the corresponding support sleeve 611. The condensation adsorption assembly 3 is arranged between the four baffle pillars 7.

[0047] The annular shutter 62 is mounted on the cross-shaped bracket 61, forming a multi-layer barrier to block and disperse the airflow entering the cryopump. The four ends of the cross-shaped bracket 61 are provided with support sleeves 611, which are connected to the baffle pillars 7 through the support sleeves 611 to ensure the stability and positioning accuracy of the first-stage baffle 6. Compared with the connection between the first-stage baffle and the inner wall of the shielding cover in the traditional cryopump, the present invention connects the first-stage baffle 6 to the bottom of the shielding cover 2 through the baffle pillars 7, and arranges the condensation adsorption assembly 3 between the four baffle pillars 7, thereby enhancing thermal management, reducing interference between the first and second stage cooling capacity, and improving the stability of the structure and the convenience of maintenance.

[0048] In one embodiment, the primary baffle 6 is made of red copper, and the outer surface of the primary baffle 6 is nickel-plated. The annular shutter 62 includes a circular sheet 621, an annular herringbone blade 622, and an annular conical blade 623 arranged in sequence from the inside to the outside, and the number of the annular herringbone blade 622 and the annular conical blade 623 is five. The cross-shaped bracket 61 is welded to the circular sheet 621, the annular herringbone blade 622, and the annular conical blade 623 respectively.

[0049] In one embodiment, the baffle support 7 is made of red copper, and the outer surface of the baffle support 7 is nickel-plated. The bottom end of the baffle support 7 is fixed to the bottom of the shielding cover 2 through a nut.

[0050] Two groups of temperature sensor interfaces 81 , a group of vacuum gauge interfaces 82 , and a group of rough pumping interfaces 83 are provided at the bottom of the pump housing 1 .

[0051] The bottom of the pump housing 1 is connected to two sets of temperature sensor interfaces 81, a set of vacuum gauge interfaces 82, and a set of roughing interfaces 83 through four flange connections. The temperature sensor interface 81 is used to install a temperature sensor to monitor the temperature changes at different positions inside the pump in real time. The vacuum gauge interface 82 is used to connect a vacuum gauge to monitor the vacuum degree in the pump in real time. The roughing interface 83 is used to connect the roughing bellows of the KF25 interface to quickly reduce the air pressure in the system at the initial start-up of the cryogenic pump, creating conditions for subsequent low-temperature operations.

[0052] The side wall of the shielding cover 2 is provided with an annular protrusion 21 .

[0053] By providing the annular protrusion 21 , the side wall strength of the shielding cover 2 is enhanced to prevent deformation.

[0054] The bottom of the pump housing 1 is provided with a carrying sleeve 84 for easy carrying using a bracket.

[0055] By providing the carrying sleeve 84 , the cryopump bracket can be connected to the cryopump through the carrying sleeve 84 , making it more convenient to carry.

[0056] The cryopump installation process of the present invention is as follows:

[0057] Connect two groups of GM refrigerators to the pump casing, connect the secondary temperature sensor to the bottom of the second cold head, connect the four baffle pillars to the shielding cover, connect the shielding cover to the first cold head, install a shielding cover gasket on the upper part of the connection between the shielding cover and the first cold head, adhere the activated carbon to the cold umbrella blades, connect the middle umbrella piece and the lower umbrella piece through heat-conducting supports, connect the cold umbrella heat-conducting sheet to the second cold head and the middle umbrella piece, connect the middle umbrella piece and the upper umbrella piece through heat-conducting supports, connect the first-level baffle to the four baffle pillars, connect the first-level temperature sensor to the first-level baffle, weld the leads of the first-level temperature sensor and the second-level temperature sensor to the two groups of temperature sensor interfaces respectively, and connect the two groups of temperature sensor interfaces, the vacuum gauge interface, and the rough pumping interface to the bottom of the pump casing.

Claims

1. A multi-refrigerator cryopump, characterized in that: The invention comprises a pump casing (1), a shielding cover (2) is arranged inside the pump casing (1), a condensation adsorption assembly (3) is arranged inside the shielding cover (2), and the cryogenic pump further comprises at least two groups of refrigerators (4), each of the refrigerators (4) is provided with a first cold head (41) and a second cold head (42), the first cold head (41) is thermally connected to the same shielding cover (2), and the second cold head (42) is thermally connected to the same condensation adsorption assembly (3).

2. A multi-refrigerator cryopump according to claim 1, characterized in that: The condensation adsorption component (3) comprises a plurality of layers of cold umbrella blades (31) and a heat-conducting support member (32) arranged between adjacent cold umbrella blades (31); an adsorption layer (33) is arranged on the cold umbrella blades (31) and the heat-conducting support member (32); the plurality of layers of the cold umbrella blades (31) are divided into an upper umbrella piece (311), a middle umbrella piece (312), and a lower umbrella piece (313) from top to bottom; the lower umbrella piece (313) is provided with an avoidance opening (3131); the second cold head (42) can pass through the avoidance opening (3131) to be connected with the middle umbrella piece (312).

3. A multi-refrigerator cryopump according to claim 2, characterized in that: A cold umbrella heat conducting sheet (5) is provided between the second cold head (42) and the middle umbrella sheet (312).

4. The multi-refrigerator cryopump according to claim 2, characterized in that: The heat-conducting support member (32) is a support ring, and the support ring located between the middle umbrella piece (312) and the lower umbrella piece (313) is arranged at the avoidance opening (3131) to allow the second cold head (42) to pass through the support ring. The adsorption layer (33) on the heat-conducting support member (32) includes a plurality of columnar coconut shell activated carbons (331) arranged on the outer side wall of the support ring.

5. The multi-refrigerator cryopump according to claim 2, characterized in that: The heat-conducting support member (32) is provided with a plurality of first through holes (321), and the cooling umbrella blade (31) is provided with a plurality of second through holes (314) that can cooperate with the first through holes (321) so as to allow bolts to fix the heat-conducting support member (32) and the cooling umbrella blade (31).

6. The multi-refrigerator cryopump according to claim 2, characterized in that: The adsorption layer (33) on the cooling umbrella blade (31) includes block coconut shell activated carbon (332).

7. The multi-refrigerator cryopump according to claim 1, characterized in that: A primary baffle (6) is provided in the shielding cover (2), and the primary baffle (6) includes a cross-shaped bracket (61) and a plurality of annular shutters (62) arranged on the cross-shaped bracket (61), and the four ends of the cross-shaped bracket (61) are provided with support sleeves (611), and four baffle pillars (7) for fixing the primary baffle (6) are provided between the shielding cover (2) and the primary baffle (6), one end of the baffle pillar (7) is connected to the bottom of the shielding cover (2), and the other end of the baffle pillar (7) is connected to the corresponding support sleeve (611), and the condensation adsorption component (3) is arranged between the four baffle pillars (7).

8. The multi-refrigerator cryopump according to claim 1, characterized in that: The bottom of the pump housing (1) is provided with two groups of temperature sensor interfaces (81), a group of vacuum gauge interfaces (82), and a group of rough pumping interfaces (83).

9. The multi-refrigerator cryopump according to claim 1, characterized in that: The side wall of the shielding cover (2) is provided with an annular protrusion (21).

10. The multi-refrigerator cryopump according to claim 1, characterized in that: The bottom of the pump housing (1) is provided with a carrying sleeve (84) for facilitating carrying using a carrying bracket.

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