Vacuumizing device based on phase change

Abstract

The invention discloses a vacuumizing device based on phase change, which comprises a shell, a vacuumizing mechanism and a sealing mechanism I. According to the device, based on saturated vapor pressure change of a phase change material, a container is filled with vapor of the phase change material at a high temperature to realize low vacuum, and the phase change material is solidified at a low temperature to realize high vacuum; and the general high vacuum requirement can be met under the assistance of various types of low vacuum pumps.

Description

Technical Field

[0001] The invention relates to the technical field of vacuum pumping devices, and in particular to a vacuum pumping device based on phase change. Background Art

[0002] High vacuum technology is a key technology in the fields of thermal insulation and electrical insulation. Generally speaking, the higher the vacuum degree, the better the thermal insulation and electrical insulation performance. For example, when the air pressure changes from 10Pa to 0.01Pa, its thermal conductivity changes from 10 -2 W / (m·K) becomes 10 -5 W / (m·K).

[0003] For high vacuum, a multi-pump cascade method is often used. For example, a vacuum system that combines a mechanical pump and a molecular pump, runs the mechanical pump to form a low vacuum environment, then turns on the molecular pump to finally achieve high vacuum. It is difficult for a single vacuum pump to directly achieve high vacuum.

[0004] However, the current multi-stage pump-connected vacuum system has disadvantages such as large size, complex structure, and difficulty in adapting to special environments. For example, in field operations, the multi-stage pump-connected vacuum system is difficult to transport and use, and needs to be improved. Summary of the invention

[0005] To solve at least one of the above technical defects, the present invention provides the following technical solutions:

[0006] The present application document discloses a phase-change based vacuum pumping device, comprising a shell, a vacuum pumping mechanism, and a sealing mechanism. The shell has a chamber disposed therein, the chamber has a connection port communicating with the outside, and a phase-change material is disposed in the chamber. The vacuum pumping mechanism is connected to the chamber to extract gas from the chamber, and the sealing mechanism is used to open and close the connection between the vacuum pumping mechanism and the chamber.

[0007] A method of using the device is as follows: the connection port is connected to a cavity to be evacuated, the evacuation mechanism is activated to extract the gas in the cavity, and then the connection between the evacuation mechanism and the cavity is disconnected through the sealing mechanism;

[0008] The phase change material is heated to cause its phase change to generate a gaseous state that fills the cavity. The connection between the vacuum pumping mechanism and the chamber is restored through a sealing mechanism, and the vacuum pumping mechanism continues to pump air. After repeated attempts, most of the gas in the cavity is phase change material vapor. The phase change material vapor changes phase after the temperature is lowered, thereby achieving the high vacuum requirement in the cavity.

[0009] Furthermore, the chamber includes a first cavity, a second cavity and a first connecting cavity. The first cavity and the second cavity are connected by the first connecting cavity. The first cavity has a connection port connected to the outside. Phase change material is arranged in the second cavity. The vacuum mechanism is connected to the first cavity.

[0010] Furthermore, the first connecting cavity is filled with a porous medium, and a channel constructed by the porous medium is used for gaseous substances to pass through. The porous medium is such as a metal wire mesh, and a micron-level channel is constructed by the metal wire mesh, which can allow gaseous substances to pass through but restricts the passage of liquid and solid phase change materials.

[0011] Furthermore, the first cavity includes an upper chamber, a lower chamber and a second connecting chamber. The upper chamber and the lower chamber are connected by the second connecting chamber. The upper chamber has a connection port connected to the outside, and can be connected to a sealing mechanism for isolation through the second connecting chamber.

[0012] Furthermore, the second connecting cavity is formed of a soft material and also includes a second sealing mechanism, which is used to clamp or loosen the shell surrounding the second connecting cavity to open or close the second connecting cavity, thereby helping to improve the flexibility of use.

[0013] Furthermore, a second valve-type sealing mechanism is provided at the second connecting cavity, and the second connecting cavity is opened and closed by the sealing mechanism, which helps to improve the flexibility of use.

[0014] Furthermore, the second connecting cavity is made of glass or soft metal, and the second connecting cavity is deformed by shrinkage at high temperature to disconnect the connection between the upper chamber and the lower chamber, which helps to improve the flexibility of use.

[0015] Furthermore, the width of the second connecting cavity is smaller than the width of the upper cavity and the lower cavity connected thereto, so as to facilitate docking with the second sealing mechanism or to facilitate fusing.

[0016] Furthermore, the first cavity, the first connecting cavity, and the second cavity are arranged in sequence along the longitudinal direction, and a connecting port is arranged on the top wall of the first cavity.

[0017] Furthermore, the phase change material is iodine, paraffin, gallium-based metal or bismuth-based metal; and the vacuum pumping mechanism is a mechanical pump type.

[0018] Furthermore, it also includes an exhaust branch connected to the chamber, the exhaust branch is connected to the air inlet of the vacuum mechanism, and a valve-type sealing mechanism is provided on the exhaust branch to facilitate docking with the vacuum mechanism.

[0019] Furthermore, a heating mechanism is included, and the heating mechanism is used to heat the phase change material.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This device is based on the change of saturated vapor pressure of phase change material. At high temperature, the vapor of phase change material fills the container to achieve low vacuum, and at low temperature, the phase change material solidifies to achieve high vacuum. It can meet general high vacuum requirements with the assistance of various types of low vacuum pumps.

[0022] 2. This device can be adapted to different vacuum systems, has a simple structure, and is highly portable, and can meet the needs of high vacuum electrical insulation or thermal insulation in special environments (such as field operations).

[0023] 3. This device has the advantages of simplified structure, easy to carry and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 is a schematic structural diagram of the vacuum pumping device in Example 1;

[0026] Figure 2 It is a schematic diagram of the connection structure of the vacuum pumping device;

[0027] Figure 3 is a schematic structural diagram of the vacuum pumping device in Example 3;

[0028] Figure 4 is a schematic structural diagram of the vacuum pumping device in Example 4;

[0029] Figure 5 is a schematic diagram of the structure of the vacuum pumping device in Example 4;

[0030] Wherein, the accompanying drawings are marked as follows:

[0031] 1. Shell; 2. Chamber; 3. Connecting port; 4. Vacuuming mechanism; 5. Phase change material; 6. Sealing mechanism 1; 7. Exhaust branch; 8. Flange; 9. Object to be vacuumed; 10. Sealing mechanism 2; 11. Gaseous phase change material; 12. Heating mechanism; 21. First cavity; 22. Second cavity; 23. First connecting cavity; 211. Upper cavity; 212. Second connecting cavity; 213. Lower cavity. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] like Figure 1As shown, the vacuum pumping device based on phase change includes a shell 1, a vacuum pumping mechanism 4, and a sealing mechanism 6. The configuration of the shell can be selected according to the needs, and this is not limited. In this example, a conventional cylindrical shell is used as an example. A chamber 2 is preformed in the shell. The chamber 2 has a connection port 3 connected to the outside. The connection port 3 is mainly used to pass gaseous substances. Its specific configuration can be based on the needs. In order to facilitate docking with external objects, flanges or metal plates can be added. Figure 2 As shown, a flange 8 is fixed at the opening of the connection port 3, and the flange 8 can be subsequently fixed to the object to be vacuumed 9. A metal plate or the like can also be placed at the connection port, and then the metal plate is welded and fixed to the object to be vacuumed, which is selected according to needs.

[0035] In this example, a phase change material 5 is placed in the chamber 2. The phase change material 5 is a gaseous phase change type, such as iodine, paraffin, gallium-based metal or bismuth-based metal, etc. In this example, iodine is placed for demonstration. Figure 1 In the state shown, the iodine is at the bottom of the chamber 2, and the connecting port 3 is at the top of the chamber 2. Of course, the specific placement position of the iodine can also be selected according to needs, such as in the middle of the chamber.

[0036] For the chamber, it can also be divided into multiple spaces. Figure 1 In the state shown, the chamber 2 includes a first cavity 21 at the top, a second cavity 22 at the bottom, and a first connecting cavity 23 connecting the two. The first cavity 21, the first connecting cavity 23, and the second cavity 22 are arranged in sequence along the longitudinal direction. A connecting port 3 is formed at the top wall of the first cavity 21, and the phase change material 5 is placed in the second cavity 22. For the first connecting cavity, a mechanism for isolation, such as a valve, can be installed, specifically, to limit the phase change material from leaving the second cavity, especially to prevent it from leaking from the connecting port when there is no phase change. Preferably, Figure 1 As shown, a porous medium is filled in the first connecting cavity 23, such as a channel constructed by the porous medium for allowing gaseous substances to pass through and restricting the passage of liquid or solid phase change materials. The porous medium is such as a metal mesh, and a micron-level channel is constructed by the metal mesh, which allows gaseous substances to pass through but restricts the passage of liquid and solid phase change materials. In order to facilitate the first connecting cavity to dock with the valve or fill the porous medium, it is preferred that the width of the first connecting cavity is smaller than the width of the first cavity and the second cavity connected thereto.

[0037] In this example, the vacuum pumping mechanism 4 is connected to the chamber 2 to extract the gas in the chamber. The vacuum pumping mechanism does not need to adopt a complex multi-pump cascade type vacuum pumping mechanism. A relatively simple mechanical pump can be used as the vacuum pumping mechanism 4, such as a common rotary vane pump. For the connection between the vacuum pumping mechanism and the shell, a pipeline is added to the air inlet of the rotary vane pump so that the pipeline extends into the chamber. Or Figure 1As shown, a pipeline, namely, an air extraction branch 7, is fixed or integrally formed on the peripheral wall of the housing 1, one end of the air extraction branch 7 is connected to the chamber 2 and the other end is connected to the air inlet of the rotary vane pump.

[0038] The connection point between the exhaust branch 7 and the chamber 2 is preferably above the phase change material 5 and below the connection port 3, which has a better vacuuming effect. Figure 1 As shown, the air extraction branch 7 is connected to the first cavity 21 above the phase change material 5. Of course, the air extraction branch can also be connected to other positions. For the connection between the air extraction branch and the housing and the rotary vane pump, such as threaded connection or flange connection, it is convenient for installation and disassembly.

[0039] In this example, the sealing mechanism 1 6 is used to open and close the connection between the vacuum pumping mechanism 4 and the chamber 2. For the sealing mechanism 1, a common valve is used as the sealing mechanism 1 6, such as a ball valve, a stop valve, etc. The valve is directly installed on the exhaust branch 7, and the exhaust branch is opened and closed by the valve. Figure 1 Of course, an external mechanism can also be selected as a sealing mechanism, such as a clamp. If the exhaust branch is formed of a soft material, such as rubber, the exhaust branch can be clamped by the clamp when it needs to be disconnected.

[0040] One method of using the device is as follows: the flange at the connection port is aligned with the object to be vacuumed, the chamber is connected with the cavity of the object to be vacuumed through the connection port, the vacuum mechanism is started to extract the gas in the cavity, and then the connection between the vacuum mechanism and the chamber is disconnected through the sealing mechanism.

[0041] The phase change material is heated to change its phase, and the gaseous phase change material fills the cavity of the object to be vacuumed. The connection between the vacuum pumping mechanism and the chamber is restored through a sealing mechanism, and the vacuum pumping mechanism continues to pump air. After repeated multiple times, most of the gas in the cavity is phase change material vapor, and the phase change material vapor changes phase and solidifies after the temperature is lowered.

[0042] In this example, iodine is used as the phase change material. At 40°C, iodine sublimates, and its saturated vapor pressure is 133 Pa. At -20°C, iodine condenses, and its saturated vapor pressure is 0.04 Pa. This allows the container cavity 10 to achieve a temperature of 10°C below -20°C. -2 Pa high vacuum degree.

[0043] Example 2

[0044] like Figure 3As shown, the difference from Example 1 is that in this example, the first cavity 21 is divided into a plurality of spaces, specifically including an upper chamber 211, a lower chamber 213 and a second connecting chamber 212 connecting the two, and the second connecting chamber 212 is used to install a sealing mechanism 2 for partitioning. Specifically, if a valve is used as the sealing mechanism 2, the shell part surrounding the second connecting chamber and the shell part surrounding the lower chamber can be relatively separated. After the desired vacuum degree is drawn, the second connecting chamber can be blocked by the sealing mechanism 2, and then the connection between the upper chamber and the lower chamber is disconnected, and the shell surrounding the second connecting chamber is separated from the shell surrounding the lower chamber. The object to be vacuumed can carry the shell part containing the upper chamber to the desired position, which is more flexible to use.

[0045] For the second connecting cavity, it is preferred that the width of the second connecting cavity 212 is smaller than the width of the upper cavity 211 and the lower cavity 213 connected thereto. Figure 3 In the state shown, the second connecting cavity 212 is in a constricted shape, which is convenient for docking with the second sealing mechanism.

[0046] Example 3

[0047] like Figure 4 As shown, the difference from Example 2 is that in this example, the sealing mechanism 10 is external, such as a clamp, and correspondingly, the shell portion surrounding the second connecting cavity 212 is formed of a soft material, such as rubber or gold.

[0048] When in use, if an alcohol lamp is used as the heating mechanism 12, the alcohol lamp is used to heat the shell surrounding the lower chamber 213, the phase change material 5 in the lower chamber 213 undergoes a phase change, and the gaseous phase change material 11 fills the first cavity and the cavity in the object to be vacuumed. Of course, other types of heating mechanisms can also be used, such as an induction cooker, gas, etc., or an electric heating tube, etc. The heating mechanism can also be fixed on or in the shell surrounding the second cavity, depending on the needs.

[0049] With a clamp as the sealing mechanism 10, when the desired vacuum degree is reached, the shell surrounding the second connecting chamber 212 can be clamped by the clamp, the second connecting chamber can be disconnected synchronously, and the connection between the upper chamber and the lower chamber can be disconnected synchronously, so that the shell surrounding the second connecting chamber can be separated from the shell surrounding the lower chamber, and the object to be vacuumed can carry the shell part containing the upper chamber to the desired position, which is more flexible to use.

[0050] Example 4

[0051] like Figure 5 As shown, the difference from Example 2 is that in this example, the shell surrounding the second connecting cavity 212 is formed of glass. After the phase change material 5 solidifies so that the cavity in the object to be evacuated obtains the required vacuum degree, it can be melted at high temperature to form the shell surrounding the second connecting cavity 212. Figure 5In the state shown, the shell surrounding the second connecting cavity 212 is melted and deformed by high temperature and seals the joint with the upper cavity. The object to be vacuumed can be moved to the desired position with the shell surrounding the upper cavity, which is more flexible to use.

[0052] Of course, the shell surrounding the second connecting cavity can also be formed of soft metal, such as copper, silver, etc.

[0053] The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A vacuum pumping device based on phase change, characterized in that: The invention comprises a shell (1), a vacuum pumping mechanism (4), and a sealing mechanism (6); a chamber (2) is arranged inside the shell (1); the chamber (2) has a connection port (3) communicating with the outside, and a phase change material (5) is arranged inside the chamber (2); the vacuum pumping mechanism (4) is connected to the chamber (2) to extract gas from the chamber, and the sealing mechanism (6) is used to open and close the connection between the vacuum pumping mechanism (4) and the chamber (2).

2. The phase-change based vacuum pumping device according to claim 1, characterized in that: The chamber (2) comprises a first cavity (21), a second cavity (22) and a first connecting cavity (23); the first cavity (21) and the second cavity (22) are connected via the first connecting cavity (23); the first cavity (21) has a connecting port (3) connected to the outside; a phase change material (5) is arranged in the second cavity (22); and the vacuum pumping mechanism (4) is connected to the first cavity (21).

3. The vacuum pumping device based on phase change according to claim 2, characterized in that: The first connecting cavity (23) is filled with a porous medium, and a channel constructed by the porous medium is used for gaseous substances to pass through.

4. The vacuum pumping device based on phase change according to claim 2, characterized in that: The first cavity (21) comprises an upper chamber (211), a lower chamber (213) and a second connecting chamber (212); the upper chamber (211) and the lower chamber (213) are connected via the second connecting chamber (212); and the upper chamber (211) has a connecting port (3) connected to the outside.

5. The phase-change based vacuum pumping device according to claim 4, characterized in that: The second connecting cavity (212) is formed of a soft material and further comprises a second sealing mechanism (10), which is used to clamp or loosen the shell surrounding the second connecting cavity (212) to open or close the second connecting cavity (212); Alternatively, a valve-type sealing mechanism 2 (10) is provided at the second connecting chamber (212), so that the sealing mechanism 2 (10) opens and closes the second connecting chamber (212); Alternatively, the second connecting cavity (212) is made of glass or soft metal, and the second connecting cavity (212) is deformed by shrinkage at high temperature so that the connection between the upper cavity (211) and the lower cavity (213) is disconnected.

6. The phase-change based vacuum pumping device according to claim 5, characterized in that: The width of the second connecting cavity (212) is smaller than the width of the upper cavity (211) and the lower cavity (213) connected thereto.

7. The phase-change based vacuum pumping device according to claim 2, characterized in that: The first cavity (21), the first connecting cavity (23), and the second cavity (22) are arranged in sequence along the longitudinal direction, and a connecting port (3) is arranged on the top wall of the first cavity (21).

8. The phase-change based vacuum pumping device according to claim 1, characterized in that: The phase change material (5) is iodine, paraffin, gallium-based metal or bismuth-based metal; and the vacuum pumping mechanism (4) is a mechanical pump type.

9. The phase-change based vacuum pumping device according to claim 1, characterized in that: It also includes an exhaust branch (7) connected to the chamber (2), the exhaust branch (7) is connected to the air inlet of the vacuum pumping mechanism (4), and a valve-type sealing mechanism (6) is provided on the exhaust branch (7).

10. The phase-change based vacuum pumping device according to claim 1, characterized in that: It also comprises a heating mechanism (12), wherein the heating mechanism (12) is used to heat the phase change material.

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