Vacuumizing system and cold trap thereof

Abstract

The invention provides a vacuumizing system and a cold trap thereof. The cold trap comprises an inner container, a first shell and a second shell which are sequentially arranged at intervals from inside to outside. A storage cavity used for containing a low-temperature medium is formed in the inner container in a hollow mode. The outer side face of the inner container forms a first cold face. The inner side face of the first shell and the outer side face of the inner container are enclosed to form a gas flow interlayer for gas to flow. The first shell is provided with an air inlet and an air outlet which are communicated with the airflow interlayer. A containing cavity is defined by the inner side face of the second shell and the outer side face of the first shell, the containing cavity is used for containing a low-temperature medium, and a second cold face is formed by the inner side face of the first shell. The first cold surface and the second cold surface are formed in the cold trap at the same time, so that the cold surface area of the cold trap is increased, the temperature difference between the inner side and the outer side of the airflow interlayer can be balanced, the guiding effect of the cold trap on the gas is enhanced, the adsorption and trapping capacity of the cold trap on impurity gas molecules in the gas is enhanced, and therefore the efficiency of the cold trap is improved.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum equipment, and in particular to a vacuum system and a cold trap thereof. Background Art

[0002] During the manufacturing process of cryogenic insulation containers, they need to be vacuumed through a vacuum system. Among them, the cold trap, as an important component of the vacuum system, mainly utilizes the characteristics of gas molecules moving from high temperature to low temperature, and uses its own low-temperature cold surface to condense and capture impurity gas molecules such as oil vapor and water vapor, thereby filtering out these impurity gas molecules to improve the vacuum efficiency and the vacuum degree of the cryogenic insulation container.

[0003] At present, the cold trap commonly used in vacuum systems generally includes an inner container and an outer shell, wherein an airflow space for gas molecules to flow is formed between the inner container and the outer shell. In actual application, by continuously filling the inner container with a cryogenic medium such as liquid nitrogen, a cold surface is formed on the outer surface of the inner container, and the different liquefaction temperatures of various gas molecules are used to condense and capture impurity gas molecules such as oil vapor and water vapor that are easily liquefied.

[0004] However, since the ambient temperature is much higher than the temperature of the cold surface, the above-mentioned cold trap will cause internal and external heat transfer and accelerate the loss of cold. The cold surface formed by the outer surface of the inner container alone can condense and capture impurity gas molecules such as oil vapor and water vapor. Under the action of heat transfer, it is easy to reduce the effect of the cold surface or even cause the cold surface to fail, which is not conducive to pumping the product to a high vacuum state. In addition, heat transfer can easily cause a large amount of condensed water to condense on the outer surface of the cold trap, increasing the difficulty of cleaning and vacuuming. Summary of the invention

[0005] The object of the present invention is to provide a vacuum pumping system and a cold trap thereof which can improve the vacuum pumping efficiency.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] According to one aspect of the present application, the present application provides a cold trap, comprising:

[0008] The inner container is hollow inside and has a storage cavity for containing a low-temperature medium; the outer side surface of the inner container forms a first cold surface;

[0009] A first shell, wherein a spacer ring is arranged on the outer side of the inner container, and the inner side of the first shell and the outer side of the inner container enclose an air flow interlayer for gas flow; an air inlet and an air outlet communicating with the air flow interlayer are arranged on the first shell, the air inlet is used to communicate with the container to be vacuumed, and the air outlet is used to communicate with a vacuuming device;

[0010] A second shell, wherein a spacer ring is arranged on the outer side of the first shell, the inner side surface of the second shell and the outer side surface of the first shell are enclosed to form a receiving cavity, the receiving cavity is used to receive a low-temperature medium, and the inner side surface of the first shell forms a second cold surface;

[0011] Wherein, the first cold surface and the second cold surface are used to condense the gas molecules passing through the air flow interlayer.

[0012] In some embodiments, a liquid inlet is provided on the second shell, and the accommodating cavity is communicated with an external low-temperature medium source through the liquid inlet, so as to allow the low-temperature medium to pass through and enter the accommodating cavity;

[0013] The inner container is provided with a liquid inlet communicated with the storage cavity, and the liquid inlet is communicated with the accommodating cavity.

[0014] In some embodiments, the liquid inlet is located at the top of the second shell;

[0015] The upper and lower parts of the inner container are respectively provided with a plurality of liquid inlets at intervals along the circumferential direction, each of the liquid inlets is connected to a liquid inlet pipe, and the inner container is connected to the accommodating cavity through the liquid inlet pipe.

[0016] In some embodiments, the top of the second shell is further provided with an overflow port, and the overflow port is communicated with the accommodating cavity;

[0017] A sewage outlet is provided at the bottom of the second shell, and the sewage outlet is communicated with the accommodating chamber; a sewage outlet is communicated with a sewage pipe, and the sewage pipe is sealed and connected with the second shell;

[0018] The sewage pipe is provided with a control valve for controlling the on-off of the sewage pipe.

[0019] In some embodiments, the air inlet is located at the top of the first shell; an air inlet pipe is connected to the air inlet, and the air inlet pipe extends outward from the second shell; the air inlet pipe is sealedly connected to the first shell and the second shell;

[0020] The air outlet is located at the bottom of the first shell; the air outlet is connected to an air outlet pipe, and the air outlet pipe extends outward from the second shell; the air outlet pipe is sealed and connected to the first shell and the second shell.

[0021] In some embodiments, the cold trap further includes an insulating layer, which is coated on the outer side of the second shell and is used for heat insulation inside the second shell.

[0022] In some embodiments, the cold trap further comprises a shell, wherein the shell spacer ring is arranged on the outer side of the second shell, and the shell and the second shell are enclosed to form an interlayer space, and when the cold trap is in a working state, the interlayer space is in a vacuum state;

[0023] The shell is provided with an evacuation port, and the evacuation port is communicated with the interlayer space.

[0024] In some embodiments, the evacuation port is located at the top of the housing;

[0025] A connecting joint is provided at the evacuation port, the connecting joint is sealedly connected to the shell, and the connecting joint is used to connect the evacuation port with a vacuum pumping device.

[0026] In some embodiments, the cold trap further comprises a gas adsorption layer disposed on the outer side of the second shell, and the gas adsorption layer is used to adsorb gas molecules in the interlayer space.

[0027] In some embodiments, the cold trap further comprises guide fins, which are arranged around the outer side of the inner container and located in the air flow interlayer, and the guide fins are used to increase the condensation area of ​​the first cold surface and guide the gas in the air flow interlayer.

[0028] According to another aspect of the present application, the present application also provides a vacuum pumping system for vacuuming a container to be vacuumed, the vacuum pumping system comprising a vacuum pumping device and a cold trap as described above, the vacuum pumping device being used to extract the gas inside the container to be vacuumed; the vacuum pumping device being used to extract the gas inside the container to be vacuumed; the air inlet of the cold trap being connected to the container to be vacuumed, and the air outlet being connected to the vacuum pumping device.

[0029] It can be seen from the above technical solution that the present invention has at least the following advantages and positive effects:

[0030] In the present invention, the cold trap is composed of an inner container, a first shell and a second shell arranged along the inner and outer intervals, wherein the inner container is used to contain a low-temperature medium, so that a first cold surface is formed on its outer side surface, and the interval between the inner container and the first shell forms an air flow interlayer for the flow of gas molecules, and a containing cavity for containing the low-temperature medium is formed between the first shell and the second shell, so that a second cold surface can be formed on the inner side surface of the first shell.

[0031] That is, in the present application, a first cold surface is formed on the inner side of the air flow interlayer, and a second cold surface is formed on the outer side of the air flow interlayer, and the low temperature of the first cold surface and the second cold surface is used to capture the gas so that the gas quickly enters the gas interlayer, and then under the action of the low temperature of the first cold surface and the second cold surface, the impurity gas molecules that are easily liquefied can be condensed into liquid or solid state and attached to the first cold surface or the second cold surface, so as to purify the gas flowing through the air flow interlayer.

[0032] Moreover, compared with the prior art, the present application forms a first cold surface and a second cold surface design inside the cold trap at the same time, thereby increasing the cold surface area of ​​the cold trap. At the same time, the design of the first cold surface and the second cold surface can balance the temperature difference between the inside and outside of the air flow interlayer, thereby avoiding the generation of condensed water on the inner container or the first shell constituting the air flow interlayer, thereby enhancing the guiding effect of the cold trap on the gas, and enhancing the cold trap's ability to adsorb and capture impurity gas molecules in the gas, thereby improving the efficiency of the cold trap. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure of the cold trap in one direction in this embodiment.

[0034] Figure 2 yes Figure 1 Cross-sectional view of the intermediate cold trap along the AA direction.

[0035] Figure 3 Schematic diagram of the structure of the cold trap in another direction in this embodiment.

[0036] Figure 4 yes Figure 3 Cross-sectional view of the intermediate cooling trap along the BB direction.

[0037] The following are the descriptions of the reference numerals:

[0038] 1. Inner container; 11. Storage cavity; 2. First shell; 21. Air flow interlayer; 3. Second shell; 32. Accommodating cavity; 41. Air inlet pipe; 42. Air outlet pipe; 43. Liquid inlet pipe; 44. Liquid inlet pipe; 45. Overflow pipe; 46. Drain pipe; 5. Insulation layer; 6. Guide fins; 7. Outer shell; 71. Interlayer space; 8. Connecting joint. DETAILED DESCRIPTION

[0039] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0040] In the description of the present application, it should be understood that in the embodiments shown in the drawings, the indications of directions or positional relationships (such as up, down, left, right, front and back, etc.) are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, the indications of these directions also change accordingly.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] When the vacuum equipment of the same specifications is used to evacuate the container to be evacuated, the vacuum degree of the container to be evacuated may differ by 0.03-0.06Pa under the same evacuation time. When the vacuum value of the container to be evacuated reaches a certain value, the vacuum value decreases slowly under the influence of certain impurity gas molecules. Simply increasing the evacuation time cannot quickly improve the vacuum degree.

[0043] Among them, impurity gas molecules refer to gas molecules that may affect the vacuum degree of the vacuum container to be evacuated, the normal operation of the vacuum equipment, etc., including oil vapor molecules, water vapor molecules, etc., and the impurity gas molecules are easy to liquefy.

[0044] To solve the above problems, the present application provides a vacuum pumping system for vacuuming a container to be vacuumed, and optimizes its structure to improve the efficiency of vacuuming using the vacuum pumping system and improve the vacuum degree of the vacuumed container.

[0045] In the present application, the vacuum system includes a vacuum device and a cold trap. The vacuum device is used as a power source to extract the gas in the container to be vacuumed. The vacuum device can be a vacuum pump.

[0046] The specific embodiments of the cold trap of the present application are described in detail below in conjunction with the accompanying drawings.

[0047] Figure 1 This is a schematic diagram of the structure of the cold trap in one direction in this embodiment. Figure 2 for Figure 1 Cross-sectional view of the intermediate cold trap along the AA direction, Figure 3 This is a schematic diagram of the structure of the cold trap in another direction in this embodiment. Figure 4 for Figure 3Cross-sectional view of the intermediate cooling trap along the BB direction.

[0048] refer to Figure 1 to Figure 4 The cold trap includes an inner container 1, a first shell 2 and a second shell 3. The inner container 1 is hollow inside to form a storage cavity 11 for containing a low-temperature medium, and the outer side of the inner container 1 forms a first cold surface. The first shell 2 is provided with a spacer ring on the outer side of the inner container 1, and the inner side of the first shell 2 and the outer side of the inner container 1 are enclosed to form an air flow interlayer 21 for gas molecules to flow. The first shell 2 is provided with an air inlet and an air outlet that are connected to the air flow interlayer 21. The air inlet is used to communicate with the container to be vacuumed, and the air outlet is used to communicate with the vacuum equipment. The second shell 3 is provided with a spacer ring on the outer side of the first shell 2, and the inner side of the second shell 3 and the outer side of the first shell 2 are enclosed to form a accommodating cavity 32. The accommodating cavity 32 is used to accommodate a low-temperature medium, and the inner side of the first shell 2 forms a second cold surface. Among them, the first cold surface and the second cold surface are used to condense the gas molecules passing through the air flow interlayer 21.

[0049] In the present application, the cold trap utilizes the principle of gas diffusion from high temperature to low temperature to guide the gas flow. Specifically, a first cold surface is formed on the inner side of the air flow interlayer 21, and a second cold surface is formed on the outer side of the air flow interlayer 21. The low temperature of the first cold surface and the second cold surface is utilized to capture the gas so that the gas quickly enters the gas interlayer. Then, under the action of the low temperature of the first cold surface and the second cold surface, the impurity gas molecules in the gas can be condensed into liquid or solid and attached to the first cold surface or the second cold surface to purify the gas flowing through the air flow interlayer 21.

[0050] Moreover, compared with the prior art, the present application forms a first cold surface and a second cold surface inside the cold trap at the same time, thereby increasing the cold surface area of ​​the cold trap. At the same time, the design of the first cold surface and the second cold surface can balance the temperature difference between the inner and outer sides of the air flow interlayer 21, thereby avoiding the generation of condensed water on the wall of the inner container 1 or the first shell 2 constituting the air flow interlayer 21, thereby enhancing the guiding effect of the cold trap on the gas, and enhancing the cold trap's ability to adsorb and capture impurity gas molecules in the gas, thereby improving the efficiency of the cold trap.

[0051] Among them, the cryogenic medium mentioned above can be liquid nitrogen, which has a high utilization efficiency. A small amount of cryogenic medium can form a larger cold surface, reduce the loss of cryogenic medium, and reduce the manpower and vacuum costs of frequently recharging the cryogenic medium.

[0052] The gas flowing into the air flow interlayer 21 mentioned above is a mixture of various gas molecules including oil vapor molecules and water vapor molecules.

[0053] refer to Figure 1 to Figure 4The axial direction of the inner container 1 extends vertically. The inner container 1 is hollow inside to form a storage cavity 11, and the storage cavity 11 is used to store a cryogenic medium. When the cryogenic medium is stored in the storage cavity 11, the cryogenic medium can transfer cold energy to the inner container 1, and a first cold surface can be formed on the outer side of the inner container 1.

[0054] The inner container 1 is provided with a liquid inlet, which is communicated with the storage chamber 11 and is used to communicate with an external low-temperature medium source so that the low-temperature medium can pass through and enter the storage chamber 11. The liquid inlet is connected to a liquid inlet pipe 43, which is sealed and connected to the inner container 1 to ensure the airtightness of the inner container 1.

[0055] In this embodiment, a plurality of liquid inlets are provided at intervals along the circumferential direction at the upper and lower portions of the inner container 1, each of which is connected to a liquid inlet pipe 43 and is respectively connected to a low-temperature medium source. This can increase the flow rate of the low-temperature medium entering the storage chamber 11 per unit time, thereby accelerating the speed of injecting the low-temperature medium into the storage chamber 11 of the inner container 1.

[0056] The first shell 2 is provided with a spacer ring on the outer side of the inner container 1. The inner side of the first shell 2 and the outer side of the inner container 1 are enclosed to form an air flow sandwich 21, and the air flow sandwich 21 is used to allow gas to flow. At this time, the liquid inlet pipe 43 is penetrated through the second shell 3 to facilitate communication with the low-temperature medium source. In addition, the liquid inlet pipe 43 is sealed and connected to the second shell 3 to ensure the airtightness of the second shell 3.

[0057] The axial direction of the first shell 2 extends vertically. Specifically, the first shell 2 is coaxially arranged with the inner container 1 so that the interval between the first shell 2 and the inner container 1 is consistent along the circumferential direction to balance the space of the airflow interlayer 21 and the gas flow in the airflow interlayer 21.

[0058] The first shell 2 is provided with an air inlet and an air outlet which are in communication with the air flow interlayer 21. The air inlet is used to communicate with the container to be vacuumed, and the air outlet is used to communicate with the vacuuming equipment. In actual application, under the action of the vacuuming equipment, the gas inside the container to be vacuumed will enter the air flow interlayer 21 through the air inlet and flow out through the air outlet.

[0059] Specifically, the air inlet is located at the top of the first shell 2, and the air inlet is located above the inner container 1. The air outlet is located at the bottom of the first shell 2, and the air outlet is located below the inner container 1. The top of the first shell 2 here refers to the highest point of the first shell 2 along the axial direction, and the bottom of the first shell 2 refers to the lowest point of the first shell 2 along the axial direction. The above design makes the air inlet direction of the cold trap, the flow direction of the gas in the air flow interlayer 21, and the air outlet direction of the cold trap consistent with the axial direction of the first shell 2, and the gas can flow into the air flow interlayer 21 from the highest point of the first shell 2, and flow out of the air flow interlayer 21 through the lowest point of the first shell 2, so that the gas can flow from the top of the inner container 1 to the bottom of the inner container 1, which increases the effective action area of ​​the first cold surface, facilitates to improve the smoothness of the air flow in the air flow interlayer 21, is conducive to ensuring the cold trap to guide and collect the gas, and is conducive to improving the efficiency of vacuuming.

[0060] In this embodiment, the air inlet is connected to an air inlet pipe 41, which is sealed to the first shell 2 to ensure the air tightness of the first shell 2. The air outlet is connected to an air outlet pipe 42, which is sealed to the first shell 2 to ensure the air tightness of the first shell 2.

[0061] The second shell 3 is provided with a spacer ring on the outer side of the first shell 2, and the inner side of the second shell 3 and the outer side of the first shell 2 are enclosed to form a receiving chamber 32, and the receiving chamber 32 is used to receive a low-temperature medium. In actual application, when the low-temperature medium is contained in the receiving chamber 32, the low-temperature medium can transfer cold with the first shell 2, and can form a second cold surface on the inner side of the first shell 2. That is, in actual application, a first cold surface is formed on the inner side of the airflow interlayer 21, and a second cold surface is formed on the outer side of the airflow interlayer 21, thereby increasing the cold surface area of ​​the cold trap. At the same time, the design of the first cold surface and the second cold surface can balance the temperature difference between the inner and outer sides of the airflow interlayer 21, avoid the generation of condensed water on the wall of the inner container 1 or the first shell 2 constituting the airflow interlayer 21, and enhance the guiding effect of the cold trap on the gas, and enhance the adsorption and capture ability of the cold trap on the impurity gas molecules in the gas, thereby improving the efficiency of the cold trap.

[0062] The axial direction of the second shell 3 extends vertically. In this embodiment, the second shell 3 is coaxially arranged with the first shell 2, so that the interval between the second shell 3 and the first shell 2 is consistent along the circumferential direction, and the space of the accommodating cavity 32 can be balanced, so that the low-temperature medium is evenly distributed in the accommodating cavity 32 to balance the temperature of the second cold surface.

[0063] The second housing 3 is provided with a liquid inlet, which is communicated with the accommodating chamber 32, and the liquid inlet is communicated with an external low-temperature medium source, so that the low-temperature medium can enter the accommodating chamber 32. When the low-temperature medium is injected into the accommodating chamber 32 through the liquid inlet, the low-temperature medium will fill the accommodating chamber 32 from bottom to top, and form convection with the gas flowing from top to bottom, which can quickly cool the gas and adsorb and capture impurity gas molecules in the gas, thereby increasing the temperature transfer efficiency between gases, shortening the vacuuming time, and improving work efficiency.

[0064] Exemplarily, the liquid inlet is located at the top of the second shell 3. During the process of injecting the low-temperature medium into the accommodating cavity 32 through the liquid inlet, the low-temperature medium will flow from top to bottom. The cold energy released by the low-temperature medium during the flow process can pre-cool the first shell 2 to reduce the temperature of the first shell 2.

[0065] The liquid inlet is connected to a liquid inlet pipe 44, and the accommodating chamber 32 is connected to an external low-temperature medium source through the liquid inlet pipe 44. The liquid inlet pipe 44 is sealed and connected to the second shell 3 to ensure the airtightness of the second shell 3.

[0066] The second shell 3 is provided with an overflow port, which is communicated with the accommodating chamber 32. Specifically, the overflow port is provided at the top of the second shell 3. In the process of continuously injecting the low-temperature medium into the accommodating chamber 32 through the liquid inlet, as the liquid level in the accommodating chamber 32 rises, the low-temperature medium in the accommodating chamber 32 overflows from the overflow port, which means that the low-temperature medium in the accommodating chamber 32 has been filled.

[0067] The overflow port is connected to an overflow pipe 45 , and the overflow pipe 45 is sealedly connected to the second shell 3 to ensure the air tightness of the second shell 3 .

[0068] In this embodiment, the accommodating chamber 32 is connected with the storage chamber 11 of the inner container 1. Specifically, the liquid inlet pipe 43 passes through the first shell 2 from the inside to the outside and extends into the accommodating chamber 32 or is flush with the outer side of the first shell 2 to connect the inner container 1 with the accommodating chamber 32. By injecting low-temperature medium into the accommodating chamber 32, the low-temperature medium in the accommodating chamber 32 can enter the storage chamber 11 of the inner container 1 through the liquid inlet pipe 43 to fill the storage chamber 11. The above design enables the second shell 3 and the inner container 1 to form a communicating vessel. In the process of injecting low-temperature medium into the accommodating chamber 32 and the storage chamber 11, when the liquid level of the low-temperature medium in the accommodating chamber 32 rises to the liquid inlet pipe 43, it will flow into the inner container 1 through the liquid inlet pipe 43, and then the liquid levels in the accommodating chamber 32 and the storage chamber 11 will rise synchronously. By observing the overflow of the low-temperature medium at the overflow port, it can be known whether the low-temperature medium in the accommodating chamber 32 and the storage chamber 11 is full. In addition, in actual application, the above design can make the temperature of the low-temperature medium in the accommodating cavity 32 consistent with that of the low-temperature medium in the storage cavity 11, and can make the temperature of the first cold surface consistent with that of the second cold surface, so as to balance the temperature inside and outside the airflow interlayer 21.

[0069] The second shell 3 is also provided with a drain port, which is communicated with the accommodating chamber 32 and is used to discharge the low-temperature medium in the accommodating chamber 32. Specifically, the drain port is provided at the bottom of the second shell 3 to completely discharge the low-temperature medium in the accommodating chamber 32.

[0070] The sewage outlet is connected to a sewage pipe 46 , and the low-temperature medium is discharged outward through the sewage pipe 46 . The sewage pipe 46 is sealed and connected to the second shell 3 to ensure the air tightness of the second shell 3 .

[0071] A control valve is provided on the sewage pipe 46 for controlling the on-off of the sewage pipe 46 .

[0072] In this embodiment, the cold trap also includes an insulating layer 5, which is coated on the outer side of the second shell 3 and is used for heat insulation inside the second shell 3 to prevent the low-temperature medium in the second shell 3 from exchanging heat with the outside, avoid the loss of coldness of the low-temperature medium, ensure that the second cold surface has a lower temperature, and ensure the ability of the second cold surface to guide gas flow and adsorb and capture impurity gas molecules, so as to enhance the effect of the cold trap.

[0073] Exemplarily, the heat insulating layer 5 may be aluminum foil.

[0074] The heat insulating layer 5 may be multi-layered, and the multi-layer heat insulating layer 5 is stacked and arranged from the inside to the outside to cover the outer side surface of the second shell 3 , which can further improve the cold-keeping and heat-insulating effect of the interior of the second shell 3 .

[0075] In this embodiment, the cold trap further includes guide fins 6, which are arranged around the outer side of the inner container 1 and are located in the air flow interlayer 21. When the guide fins 6 are in contact with the first cold surface, cold energy is transferred, which can increase the condensation area of ​​the first cold surface, so that the cold trap in this embodiment has cold surfaces on both the inner and outer sides and the inside of the air flow interlayer 21, which expands the cold surface condensation area of ​​the cold trap, increases the gas conduction capacity and the adsorption and capture capacity of impurity gas molecules, and improves the vacuum effect.

[0076] In this embodiment, the guide fins 6 are spirally wound around the outer side of the inner container 1, so that the gas passing through the airflow interlayer 21 from top to bottom can form a continuous vortex effect to strengthen the convection between the gas and the surface of the guide fins 6, so that the impurity gas molecules in the gas can quickly absorb the cold on the guide fins 6, and condense and adhere to the surface of the guide fins 6, thereby improving the ability of the guide fins 6 to guide the gas and adsorb and capture the impurity gas molecules, so as to improve the evacuation effect of the cold trap. At the same time, the spiral guide fins 6 also help to reduce the flow resistance of the gas and reduce the pressure loss to improve the smoothness of the gas flow.

[0077] Exemplarily, the guide fin 6 is a fin-type structure.

[0078] In other embodiments, the number of the guide fins 6 may be multiple, and the multiple guide fins 6 are arranged on the outer side of the inner container along the vertical interval ring.

[0079] In this embodiment, the cold trap further includes a shell 7. The shell 7 is arranged at the outer side of the second shell 3, and the shell 7 and the second shell 3 are enclosed to form an interlayer space 71. When the cold trap is in working state, the interlayer space 71 is in a vacuum state. Among them, the interlayer space 71 in a vacuum state has the function of cold insulation and heat insulation, which can further prevent the second shell 3 and the structure located inside it from directly contacting and transferring heat with the outside to reduce the loss of cold. At the same time, the design can also ensure the ultra-low temperature of the first cold surface, the second cold surface and the guide fin 6 to improve the guiding effect on the gas and the adsorption and capture ability of the impurity gas molecules, and enhance the effect of vacuuming by using the cold trap. In addition, the shell 7 can seal the second shell 3 and the structure located inside it, avoid the generation of condensed water on the surface of the second shell 3, the first shell 2, the inner container 1 and other structures, ensure the extremely low degassing rate of the vacuuming system of the cold trap using this embodiment, improve the efficiency and effect of vacuuming, so that the container to be vacuumed can meet the requirements of higher vacuum degree.

[0080] Since the second shell 3 is provided with an insulating layer 5 outside, at this time, the insulating layer 5 is located in the interlayer space 71, and the insulating layer 5 can also play a role in keeping the interlayer space 71 cool and insulating, so that the interlayer space 71 can maintain a static high vacuum state for a long time.

[0081] At this time, one end of the air inlet pipe 41 is connected to the air inlet of the first shell 2, and the other end passes through the second shell 3 and the outer shell 7 from the inside to the outside in sequence, and extends out of the outer shell 7, and the air inlet pipe 41 is sealed and connected to the first shell 2, the second shell 3 and the outer shell 7 to ensure the air tightness of the first shell 2, the second shell 3 and the outer shell 7. One end of the air outlet pipe 42 is connected to the air outlet of the first shell 2, and the other end passes through the second shell 3 and the outer shell 7 from the inside to the outside in sequence, and extends out of the outer shell 7, and the air outlet pipe 42 is sealed and connected to the first shell 2, the second shell 3 and the outer shell 7 to ensure the air tightness of the first shell 2, the second shell 3 and the outer shell 7. One end of the liquid inlet pipe 44 is connected to the liquid inlet of the second shell 3, and the other end passes through and extends out of the outer shell 7, and the liquid inlet pipe 44 is sealed and connected to the second shell 3 and the outer shell 7 to ensure the air tightness of the second shell 3 and the outer shell 7. One end of the overflow pipe 45 is communicated with the overflow port of the second shell 3, and the other end passes through and extends out of the shell 7, and the overflow pipe 45 is sealed and connected to the second shell 3 and the shell 7 to ensure the airtightness of the second shell 3 and the shell 7. One end of the sewage pipe 46 is communicated with the sewage outlet of the second shell 3, and the other end passes through and extends out of the shell 7, and the sewage pipe 46 is sealed and connected to the second shell 3 and the shell 7 to ensure the airtightness of the second shell 3 and the shell 7.

[0082] In this embodiment, the axis of the shell 7 extends vertically. Specifically, the shell 7 is coaxially arranged with the second shell 3 of the inner container 1, so that the interval between the shell 7 and the second shell 3 is kept consistent in the circumferential direction to balance the interlayer space 71 and balance the pressure of the interlayer space 71 in a vacuum state on the second shell 3 in the circumferential direction.

[0083] The shell 7 is provided with an evacuation port, which is communicated with the interlayer space 71 and is used to communicate with a vacuum pumping device to evacuate the interlayer space 71. Specifically, the evacuation port is located at the top of the shell 7.

[0084] A connecting joint 8 is provided at the evacuation port, and the connecting joint 8 is sealedly connected to the housing 7 and is used to connect the evacuation port with the vacuum equipment.

[0085] In this embodiment, the cold trap further includes a gas adsorption layer disposed on the outer side of the second shell 3 , and the gas adsorption layer is used to adsorb gas molecules in the interlayer space 71 to improve the efficiency of evacuating the interlayer space 71 and improve the vacuum degree of the interlayer space 71 .

[0086] Exemplarily, the gas adsorption layer may be a molecular sieve adsorbent. When evacuating, the molecular sieve adsorbent can effectively remove impurities in the gas through its unique microporous structure and adsorption characteristics, thereby achieving high purity and high vacuum in the interlayer space 71.

[0087] An exemplary operation process of the above cold trap in actual use is listed as follows:

[0088] The air inlet is connected to the container to be vacuumed, and the air outlet is connected to the vacuuming equipment.

[0089] The interlayer space 71 is evacuated by vacuuming the interlayer space 71 through the evacuation port with the aid of vacuuming equipment, so that the interlayer space 71 is in a high vacuum state. Moreover, under the action of the heat insulating layer 5 and the gas adsorption layer, the interlayer space 71 can maintain a static high vacuum state for a long time.

[0090] During the vacuuming process, a cryogenic medium is injected into the accommodating chamber 32 through the liquid inlet pipe 44. After the liquid level of the cryogenic medium in the accommodating chamber 32 rises to a certain height, part of the cryogenic medium enters the storage chamber 11 of the inner container 1 through the pipe mouth of the liquid inlet pipe 43. Then, the liquid level in the accommodating chamber 32 rises synchronously with the liquid level in the storage chamber 11 until the cryogenic medium overflows from the mouth of the overflow pipe 45, indicating that the accommodating chamber 32 and the storage chamber 11 are filled with the cryogenic medium. The cryogenic medium transfers cold energy with the inner container 1 and the first shell 2 to form a first cold surface on the outer side of the inner container 1 and a second cold surface on the inner side of the first shell 2. Under the action of the first cold surface, the guide fin 6 transfers cold energy with the first cold surface to increase the condensation area of ​​the first cold surface. That is, there are cold surfaces on both the inner and outer sides and the inside of the interlayer space 71.

[0091] Since the temperature inside the container to be evacuated is much higher than the temperature of the cold surface inside the cold trap, according to the characteristics of gas molecules moving from high temperature to low temperature, the gas inside the container to be evacuated extracted by the vacuum equipment will be collected and captured on the surfaces of the first cold surface, the second cold surface, and the guide fins 6 after entering the air flow interlayer 21 of the cold trap from the air inlet, so that the impurity gas molecules in the gas condense and adhere to the surfaces of the first cold surface, the second cold surface, and the guide fins 6. Then, under the action of the guide fins 6, other components in the gas except the impurity gas molecules can smoothly pass through the air flow interlayer 21 and be evacuated by the vacuum equipment through the air outlet, thereby achieving the purpose of improving the evacuation efficiency and the purpose of increasing the vacuum degree, and at the same time blocking the impurity gas molecules from entering the vacuum equipment to ensure the stability of the vacuum system.

[0092] It can be seen from the above technical solution that the present invention has at least the following advantages and positive effects:

[0093] In the present application, the cold trap is composed of an inner container, a first shell and a second shell arranged along the inner and outer intervals, wherein the inner container is used to contain a cryogenic medium, and under the action of the cold energy dissipation and transfer of the cryogenic medium, a first cold surface can be formed on the outer side surface of the inner container; the interval between the inner container and the first shell forms an air flow interlayer for the flow of gas molecules; and a containing cavity for containing the cryogenic medium is formed between the first shell and the second shell, and under the action of the cold energy dissipation and transfer of the cryogenic medium, a second cold surface can be formed on the inner side surface of the first shell.

[0094] That is, in the present application, a first cold surface is formed on the inner side of the air flow interlayer, and a second cold surface is formed on the outer side of the air flow interlayer, and the low temperature of the first cold surface and the second cold surface is used to capture the gas so that the gas quickly enters the gas interlayer, and then under the action of the low temperature of the first cold surface and the second cold surface, the impurity gas molecules in the gas can be condensed into liquid or solid and attached to the first cold surface or the second cold surface, so as to purify the gas flowing through the air flow interlayer.

[0095] Moreover, compared with the prior art, the present application forms a design of a first cold surface and a second cold surface simultaneously inside the cold trap, thereby increasing the cold surface area of ​​the cold trap. At the same time, the design of the first cold surface and the second cold surface can balance the temperature difference between the inside and outside of the air flow interlayer, thereby avoiding the generation of condensed water on the inner container wall or the first shell forming the air flow interlayer, thereby enhancing the guiding effect of the cold trap on the gas, and enhancing the cold trap's ability to adsorb and capture impurity gas molecules in the gas, thereby improving the efficiency of the cold trap.

[0096] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A cold trap, characterized in that: include: The inner container is hollow inside and has a storage cavity for containing a low-temperature medium; the outer side surface of the inner container forms a first cold surface; A first shell, wherein a spacer ring is arranged on the outer side of the inner container, and the inner side of the first shell and the outer side of the inner container enclose an air flow interlayer for gas flow; an air inlet and an air outlet communicating with the air flow interlayer are arranged on the first shell, the air inlet is used to communicate with the container to be vacuumed, and the air outlet is used to communicate with a vacuuming device; A second shell, wherein a spacer ring is arranged on the outer side of the first shell, the inner side surface of the second shell and the outer side surface of the first shell are enclosed to form a receiving cavity, the receiving cavity is used to receive a low-temperature medium, and the inner side surface of the first shell forms a second cold surface; The first cold surface and the second cold surface are used to condense gas molecules passing through the air flow interlayer.

2. The cold trap according to claim 1, characterized in that The second shell is provided with a liquid inlet, and the accommodating cavity is communicated with an external low-temperature medium source through the liquid inlet, so as to allow the low-temperature medium to pass through and enter the accommodating cavity; The inner container is provided with a liquid inlet communicated with the storage cavity, and the liquid inlet is communicated with the accommodating cavity.

3. The cold trap according to claim 2, characterized in that The liquid inlet is located at the top of the second shell; The upper and lower parts of the inner container are respectively provided with a plurality of liquid inlets at intervals along the circumferential direction, each of the liquid inlets is connected to a liquid inlet pipe, and the inner container is connected to the accommodating cavity through the liquid inlet pipe.

4. The cold trap according to claim 2, characterized in that: The top of the second shell is also provided with an overflow port, and the overflow port is communicated with the accommodating cavity; A sewage outlet is provided at the bottom of the second shell, and the sewage outlet is communicated with the accommodating chamber; a sewage outlet is communicated with a sewage pipe, and the sewage pipe is sealed and connected with the second shell; The sewage pipe is provided with a control valve for controlling the on-off of the sewage pipe.

5. The cold trap according to claim 1, characterized in that The air inlet is located at the top of the first shell; an air inlet pipe is connected to the air inlet, and the air inlet pipe extends outward from the second shell; the air inlet pipe is sealedly connected to the first shell and the second shell; The air outlet is located at the bottom of the first shell; the air outlet is connected to an air outlet pipe, and the air outlet pipe extends outward from the second shell; the air outlet pipe is sealed and connected to the first shell and the second shell.

6. The cold trap according to claim 1, characterized in that The cold trap further comprises a heat insulating layer, which is coated on the outer side of the second shell and is used for heat insulation inside the second shell.

7. The cold trap according to claim 1, characterized in that The cold trap further comprises a shell, wherein the shell spacer ring is arranged on the outer side of the second shell, and the shell and the second shell are enclosed to form an interlayer space, and when the cold trap is in a working state, the interlayer space is in a vacuum state; The shell is provided with an evacuation port, and the evacuation port is communicated with the interlayer space.

8. The cold trap according to claim 7, characterized in that The evacuation port is located at the top of the housing; A connecting joint is provided at the evacuation port, the connecting joint is sealedly connected to the shell, and the connecting joint is used to connect the evacuation port with a vacuum pumping device.

9. The cold trap according to claim 7, characterized in that: The cold trap further comprises a gas adsorption layer arranged on the outer side of the second shell, and the gas adsorption layer is used for adsorbing gas molecules in the interlayer space.

10. The cold trap according to claim 1, characterized in that: The cold trap further comprises guide fins, which are arranged around the outer side of the inner container and located in the air flow interlayer. The guide fins are used to increase the condensation area of ​​the first cold surface and guide the gas in the air flow interlayer.

11. A vacuum pumping system for vacuuming a container to be vacuumed, characterized in that: The vacuum system comprises a vacuum device and a cold trap as described in any one of claims 1 to 10, wherein the vacuum device is used to extract gas from the inside of the container to be vacuumed; the air inlet of the cold trap is connected to the container to be vacuumed, and the air outlet is connected to the vacuum device.

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