Phase change based vacuum pumping device

Abstract

The application discloses a phase change-based vacuumizing device, which comprises a shell, a vacuumizing mechanism and a sealing mechanism one. The device is based on the saturation vapor pressure change of a phase change material. At high temperature, the phase change material vapor fills the container to realize low vacuum. At low temperature, the phase change material solidifies to realize high vacuum. The device can realize general high vacuum demand with the assistance of various types of low vacuum pumps.

Description

Technical Field

[0001] This invention relates to the field of vacuum pumping device technology, and more specifically to a vacuum pumping device based on phase change. Background Technology

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

[0003] For achieving high vacuum levels, a multi-pump cascade approach is commonly used. This involves combining a mechanical pump with a molecular pump in a vacuum system. The mechanical pump creates a low vacuum environment, which is then activated by the molecular pump to achieve the high vacuum. A single vacuum pump cannot directly achieve a high vacuum level.

[0004] However, current multi-stage pump vacuum systems have drawbacks such as large size, complex structure, and difficulty in adapting to special environments. For example, multi-stage pump vacuum systems are difficult to transport and apply in field operations, and improvements are needed. Summary of the Invention

[0005] To address at least one of the aforementioned technical deficiencies, the present invention provides the following technical solution:

[0006] This application discloses a phase change-based vacuum pumping device, including a housing, a vacuum pumping mechanism, and a sealing mechanism. The housing has a chamber with a connection port to the outside. A phase change material is disposed inside the chamber. The vacuum pumping mechanism is connected to the chamber to extract gas from the chamber. The sealing mechanism is used to open and close the connection between the vacuum pumping mechanism and the chamber.

[0007] One method of using this device is as follows: the vacuuming mechanism is activated to extract the gas in the cavity by connecting the connection port to the cavity, and then the connection between the vacuuming mechanism and the cavity is disconnected by the sealing mechanism.

[0008] The phase change material is heated to cause a phase change, and the resulting gaseous state fills the cavity. The connection between the vacuum pumping mechanism and the cavity is restored through a sealing mechanism, and the vacuum pumping mechanism continues to pump gas. After repeated cycles, most of the gas in the cavity is phase change material vapor. The phase change material vapor undergoes a phase change after the temperature decreases, 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 that communicates with the outside. A phase change material is disposed in the second cavity. The vacuum pumping mechanism is connected to the first cavity.

[0010] Furthermore, the first connecting cavity is filled with a porous medium, and the channels constructed by the porous medium are used to allow gaseous substances to pass through. The porous medium is such as a metal mesh, and the metal mesh is used to construct micron-level channels. These channels allow gaseous substances to pass through but restrict 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 that communicates with the outside world and can be connected to a sealing mechanism or the like 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. The second sealing mechanism clamps or releases the shell surrounding the second connecting cavity to open or close the second connecting cavity, which helps to improve the flexibility of use.

[0013] Furthermore, a valve-type sealing mechanism 2 is provided at the second connecting cavity to open and close the second connecting cavity, which helps to improve the flexibility of use.

[0014] Furthermore, the second connecting cavity is made of glass or soft metal. By shrinking and deforming the second connecting cavity at high temperature, the connection between the upper and lower chambers is broken, 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 and lower chambers at the point of contact with it, which facilitates docking with the sealing mechanism or facilitates melting.

[0016] Furthermore, the first cavity, the first connecting cavity, and the second cavity are arranged sequentially along the longitudinal direction, and a connecting port is provided at the top wall of the first cavity.

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

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

[0019] Furthermore, it also includes a heating mechanism for heating the phase change material.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] 1. This device is based on the saturated vapor pressure change of phase change materials. At high temperature, the phase change material vapor 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 high portability, and can meet the high vacuum electrical insulation or thermal insulation requirements of special environments (such as field operations).

[0023] 3. This device has the advantages of simple structure, easy portability and low cost. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

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

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

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

[0030] The attached figures are labeled as follows:

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

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

[0033] Example 1

[0034] like Figure 1As shown, this phase-change-based vacuum pumping device includes a housing 1, a vacuum pumping mechanism 4, and a sealing mechanism 6. The configuration of the housing can be selected according to requirements and is not limited here. This example uses a conventional cylindrical housing, with a pre-formed chamber 2 inside. The chamber 2 has a connection port 3 connecting to the outside, primarily for the passage of gaseous substances. Its specific configuration can be customized. For convenient 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, which can then be used to fix the object 9 to be vacuumed. Alternatively, a metal plate can be placed at the connection port and then welded to the object to be vacuumed, depending on the requirements.

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

[0036] The chamber can also be divided into multiple spaces. Figure 1 In the illustrated state, chamber 2 comprises a first cavity 21 located above, a second cavity 22 located below, 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 longitudinally. A connection 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. The first connecting cavity can be used to install a mechanism for isolation, such as a valve, specifically to restrict the phase change material from leaving the second cavity, and especially to prevent leakage from the connection port when the phase change is not in progress. Preferably... Figure 1 As shown, the first connecting cavity 23 is filled with a porous medium, such as a porous medium-structured channel for the passage of gaseous substances while restricting the passage of liquid or solid phase change materials. The porous medium could be a metal mesh, with the mesh forming micron-sized channels that allow the passage of gaseous substances but restrict the passage of liquid or solid phase change materials. To facilitate the connection of the first connecting cavity to a valve or the filling with a porous medium, it is preferable that the width of the first connecting cavity is smaller than the width of the first and second cavities at its connection point.

[0037] In this example, the vacuum pumping mechanism 4 is connected to chamber 2 to extract gas from the chamber. The vacuum pumping mechanism does not need to be a complex multi-pump cascade type; a relatively simple mechanical pump, such as a common rotary vane pump, can suffice as vacuum pumping mechanism 4. Regarding the connection between the vacuum pumping mechanism and the housing, a pipe can be added to the inlet of the rotary vane pump, extending into the chamber. Or, as... Figure 1As shown, a pipe, namely the air extraction branch 7, is fixed or integrally formed on the periphery 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 between the evacuation branch 7 and the chamber 2 is preferably located above the phase change material 5 and below the connection port 3, which provides better vacuuming performance. Figure 1 As shown, the extraction branch 7 is connected to the first cavity 21 above the phase change material 5. Of course, the extraction branch can also be connected to other locations. For the connection between the extraction branch and the housing and the rotary vane pump, such as threaded connection or flange connection, installation and disassembly are convenient.

[0039] In this example, sealing mechanism 6 is used to connect and disconnect the vacuum pumping mechanism 4 and the chamber 2. For sealing mechanism 6, a common valve such as a ball valve or gate valve can be used. The valve is directly installed on the vacuum branch 7, and the vacuum branch is opened and closed through the valve. Figure 1 As shown. Of course, an external mechanism can also be selected as the sealing mechanism, such as a clamp. If the air extraction branch is made of a soft material, such as rubber, the clamp can be used to clamp the air extraction branch when it is necessary to disconnect the connection.

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

[0041] The phase change material is heated to cause it to change phase. The gaseous phase change material fills the cavity of the object to be evacuated. The connection between the vacuum pumping mechanism and the cavity is restored by a sealing mechanism, and the vacuum pumping mechanism continues to pump air. After repeated cycles, most of the gas in the cavity is phase change material vapor. The phase change material vapor solidifies after the temperature decreases.

[0042] In this example, iodine is used as the phase change material. Iodine sublimates at 40°C, with a saturated vapor pressure of 133 Pa, and iodine condenses at -20°C, with a saturated vapor pressure of 0.04 Pa. This allows the container cavity to achieve 10 [units of pressure] in an environment below -20°C. -2 High vacuum of Pa.

[0043] Example 2

[0044] like Figure 3As shown, the difference from Embodiment 1 is that the first cavity 21 is divided into multiple spaces, specifically including an upper chamber 211, a lower chamber 213, and a second connecting cavity 212 connecting the two. The second connecting cavity 212 is used to install a sealing mechanism 2 for isolation. Specifically, a valve is used as the sealing mechanism 2. The housing portion forming the second connecting cavity and the housing portion forming the lower chamber can be relatively separated. After the required vacuum level is achieved, the second connecting cavity can be sealed by the sealing mechanism 2, thereby disconnecting the connection between the upper and lower chambers and separating the housing portion forming the second connecting cavity from the housing portion forming the lower chamber. The object to be evacuated can be carried to the desired position with the housing portion containing the upper chamber, making it more flexible to use.

[0045] For the second connecting cavity, it is preferable that the width of the second connecting cavity 212 is smaller than the width of the upper cavity 211 and the lower cavity 213 at which it connects. Figure 3 In the state shown, the second connecting cavity 212 is constricted, which facilitates docking with the sealing mechanism 2.

[0046] Example 3

[0047] like Figure 4 As shown, the difference from Embodiment 2 is that the sealing mechanism 2 10 in this example is an external type, such as a clamp. Correspondingly, the housing part surrounding the second connecting cavity 212 is molded with a soft material, such as rubber or gold.

[0048] In use, if an alcohol lamp is used as the heating mechanism 12, the alcohol lamp heats the shell surrounding the lower chamber 213. The phase change material 5 inside the lower chamber 213 undergoes a phase change, and the gaseous phase change material 11 fills the first cavity and the cavity inside the object to be evacuated. Of course, other types of heating mechanisms can also be used, such as induction cookers, gas stoves, or electric heating elements. The heating mechanism can also be fixed to or inside the shell surrounding the second cavity, depending on the requirements.

[0049] Using clamps as sealing mechanism 210, when the required vacuum level is reached, the clamps can clamp the shell forming the second connecting cavity 212, simultaneously disconnecting the second connecting cavity and simultaneously disconnecting the connection between the upper and lower chambers. This allows the shell forming the second connecting cavity to be separated from the shell forming the lower chamber, and the object to be evacuated can be carried to the required position with the shell containing the upper chamber, making it more flexible to use.

[0050] Example 4

[0051] like Figure 5 As shown, the difference from Example 2 is that the shell forming the second connecting cavity 212 in this example is made of glass. After the phase change material 5 solidifies to obtain the required vacuum level in the cavity of the object to be evacuated, the shell forming the second connecting cavity 212 can be formed by high-temperature melting. Figure 5In the state shown, the shell forming the second connecting cavity 212 is melted and deformed by high temperature and the docking point with the upper cavity is sealed. The object to be evacuated can be moved to the required position along with the shell forming the upper cavity, making it more flexible to use.

[0052] Of course, the shell forming the second connecting cavity can also be made of soft metals such as copper or silver.

[0053] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A vacuuming method, characterized in that: The system includes a vacuum pumping device. The object to be vacuumed is connected to the flange at the connection port. The vacuum pumping mechanism is activated to extract the gas from the cavity of the object to be vacuumed. Then, the connection between the vacuum pumping mechanism and the cavity is disconnected by a sealing mechanism. The phase change material is heated to cause it to change phase. The gaseous phase change material fills the cavity of the object to be vacuumed. The connection between the vacuum pumping mechanism and the cavity is restored by the sealing mechanism, and the vacuum pumping mechanism continues to pump gas. After repeating this process multiple times, most of the gas in the cavity of the object to be vacuumed is phase change material vapor. The phase change material vapor solidifies after the temperature decreases to achieve a high vacuum. The phase change-based vacuum pumping device includes a housing (1), a vacuum pumping mechanism (4), and a sealing mechanism (6). The housing (1) has a chamber (2) inside, and the chamber (2) has a connection port (3) that communicates with the outside. The chamber (2) is filled with a phase change material (5). The vacuum pumping mechanism (4) communicates with the chamber (2) to extract gas from the chamber. The sealing mechanism (6) is used to open and close the connection between the vacuum pumping mechanism (4) and the chamber (2). The chamber (2) includes 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 by the first connecting cavity (23). The first cavity (21) has a connection port (3) that communicates with the outside. The second cavity (22) is provided with a phase change material (5). The vacuum pumping mechanism (4) is connected to the first cavity (21). The first connecting cavity (23) is filled with a porous medium, and the channels constructed by the porous medium are used to allow gaseous substances to pass through; The phase change material (5) is iodine, paraffin, gallium-based metal or bismuth-based metal; it also includes a heating mechanism (12) for heating the phase change material.

2. The vacuuming method as described in claim 1, characterized in that: The first cavity (21) includes 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 by the second connecting chamber (212). The upper chamber (211) has a connection port (3) that communicates with the outside.

3. The vacuuming method as described in claim 2, characterized in that: The second connecting cavity (212) is made of soft material and also includes a sealing mechanism two (10), which clamps or releases the shell surrounding the second connecting cavity (212) to open or close the second connecting cavity (212); Alternatively, a valve-type sealing mechanism two (10) may be provided at the second connecting cavity (212) to open or close the second connecting cavity (212); Alternatively, the second connecting cavity (212) may be made of glass or soft metal, and the second connecting cavity (212) may be deformed by high temperature to disconnect the connection between the upper cavity (211) and the lower cavity (213).

4. The vacuuming method as described in claim 3, 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 to it.

5. The vacuuming method as described in claim 1, 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 provided at the top wall of the first cavity (21).

6. The vacuuming method as described in claim 1, characterized in that: The vacuum pumping mechanism (4) is a mechanical pump type.

7. The vacuuming method as described in claim 1, characterized in that: It also includes an air extraction branch (7) connected to the chamber (2), the air extraction branch (7) being connected to the air inlet of the vacuum mechanism (4), and a valve-type sealing mechanism (6) being provided on the air extraction branch (7).

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