Atmospheric preconcentrator and method
By using the connecting method of movable heat conductors in the atmospheric preconcentrator, the problems of low heat transfer efficiency and poor refrigeration effect are solved, and the efficient heating and refrigeration process is achieved, extending the service life of the equipment.
Patent Information
- Application Number
- CN202411945888.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-04-11
AI Technical Summary
The existing atmospheric preconcentrators have problems such as low heat transfer efficiency, poor cooling effect, and heat transfer affecting heating efficiency during heating and cooling.
The movable heat conductor is connected to the refrigerator during refrigeration, and the second heat conductor with a high thermal conductivity is used to transfer heat; during heating, the cold trap is separated from the refrigerator, and the cold trap is only heated by the heating module.
It improves heat transfer effect and heating efficiency, avoids heat transfer to the refrigerator, extends the service life of the cold trap, and improves the reliability of the instrument.
Smart Images
Figure CN119804089A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to atmospheric measurement, and in particular to an atmospheric pre-concentrator and method. Background Art
[0002] The atmospheric pre-concentrator removes H2O, CO2, N2 and inert gases from the sample gas containing VOCs (volatile organic compounds), and only retains the VOCs components to be used for analysis. The cold trap in the atmospheric pre-concentrator is a key point to achieve this function. After the gas is adsorbed and H2O, CO2, N2 and inert gases are removed in the cold trap, the temperature will rise rapidly for desorption.
[0003] There are three main types of atmospheric pre-concentrators on the market: 1. Electronic semiconductor refrigeration: The main problem of this method is that the refrigeration temperature can only reach within -50°C, which is not suitable for applications with high detection sensitivity requirements.
[0004] 2. Liquid nitrogen refrigeration. The main problems of this method are: 1. It needs to release pressure regularly, which produces a large amount of nitrogen and is dangerous; 2. The cost of use is high, and liquid nitrogen is a consumable; 3. The liquid nitrogen tanks used in atmospheric pre-concentrators are all above 100L, which is inconvenient to transport.
[0005] 3. The refrigerator can achieve a lower refrigeration temperature (below -150°C) and does not require the use of consumables such as liquid nitrogen. It is safe and reliable.
[0006] The cold trap is directly connected to the refrigerator. When heated, the heat of the cold trap will be transferred to the refrigerator. The refrigerator is large in size and heat capacity, which not only affects the heating efficiency, but also may damage the refrigerator. The main heating method is to install the heating wire or heating plate directly on the cold trap to directly transfer the heat to the cold trap.
[0007] In order to solve the above problems, the existing solutions are mainly: 1. Reduce the contact area between the cold trap and the refrigerator. When the contact area is reduced, the heat transfer path becomes smaller, but the refrigeration efficiency of the refrigerator becomes worse.
[0008] 2. Use materials with low thermal conductivity between the cold trap and the refrigerator. The cold trap is covered with glass fiber sleeves and Teflon heat shrink sleeves, which play a certain role in heat insulation. The cold head is made of anodized aluminum alloy material to reduce heat conduction between the cold trap and the cold head, but this will also affect the refrigeration efficiency of the cold trap.
[0009] In the above two solutions, the heat transfer efficiency between the cold trap and the refrigerator is poor, and the cooling effect of the cold trap is poor; while during heating, the heat will still be transferred to the refrigerator, which will also affect the heating efficiency. Summary of the invention
[0010] In order to solve the deficiencies in the above-mentioned prior art solutions, the present invention provides an atmospheric pre-concentrator.
[0011] The objective of the present invention is achieved through the following technical solutions: An atmospheric pre-concentrator comprises a delivery pipe, a cold trap, a refrigerator and a heating module; the atmospheric pre-concentrator also comprises: A shell and a cold head, wherein the delivery pipe is arranged in the shell, and the cold head is arranged in the shell and connected to the refrigerator; a first heat conducting member, the first heat conducting member being connected to the cold trap; A second heat-conducting member and a driving module, wherein one end of the second heat-conducting member is connected to the cold head, and the other end is selectively connected to or separated from the first heat-conducting member under the control of the driving module.
[0012] The object of the present invention is also to provide a working method of the atmospheric pre-concentrator according to the present invention, and the object of the invention is achieved by the following technical solutions: The working method of the atmospheric pre-concentrator according to the present invention is specifically as follows: When the cold trap needs to be refrigerated, under the drive of the driving module, the second heat-conducting member is connected to the first heat-conducting member, so that the refrigerator is sequentially connected to the cold head, the second heat-conducting member, the first heat-conducting member and the cold trap; When the cold trap needs to be heated, the second heat conducting member is separated from the first heat conducting member under the driving of the driving module, and the heating module heats the cold trap.
[0013] Compared with the prior art, the present invention has the following beneficial effects: 1. Accurate results; This scheme uses the "active" method, that is, when heating, the cold trap and the refrigerator are separated, only the cold trap is heated, the heating efficiency is high, and the heat will not be transferred to the cold trap, which does not affect the service life of the cold trap; when cooling, the cold trap and the refrigerator are connected, and the heat of the cold trap is transferred to the refrigerator through the second heat-conducting member. The second heat-conducting member has a high thermal conductivity and a large heat-conducting area, and the heat transfer effect is good; 2. Good working reliability; The cold trap, refrigerator and cylinder are all directly fixed outside the vacuum shell. There is no relative displacement between the transmission tube and the cold trap. The sealing reliability is good, reducing the risk of gas leakage in the instrument. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The disclosure of the present invention will become easier to understand with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only used to illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention. In the drawings: Figure 1 is a simplified structural diagram of an atmospheric pre-concentrator according to the present invention; Figure 2 is a schematic diagram of the connection relationship of the second heat conducting member according to the present invention; Figure 3 1 is a simplified structural diagram of the atmospheric drive module according to the present invention. DETAILED DESCRIPTION
[0015] Figure 1-Figure 3 The following description describes optional specific embodiments of the present invention to teach those skilled in the art how to implement and reproduce the present invention. In order to teach the technical solution of the present invention, some conventional aspects have been simplified or omitted. Those skilled in the art will understand that variations or replacements derived from these specific embodiments will be within the scope of the present invention. Those skilled in the art will understand that the following features can be combined in various ways to form multiple variations of the present invention. Thus, the present invention is not limited to the following optional specific embodiments, but is only limited by the claims and their equivalents.
[0016] Example 1.
[0017] like Figure 1 As shown, an atmospheric pre-concentrator according to an embodiment of the present invention comprises: The delivery pipe 52, the cold trap 51, the refrigerator 21 and the heating module 71 are all prior art in the art; A housing 11 and a cold head 22, wherein the delivery pipe 52 is disposed in the housing 11, and the cold head 22 is disposed in the housing 11 and connected to the refrigerator 21; A first heat conducting member 31, wherein the first heat conducting member 31 is connected to the cold trap 51; A second heat-conducting member 32 and a driving module 41, one end of the second heat-conducting member 32 is connected to the cold head 22, and the other end is selectively connected to or separated from the first heat-conducting member 31 under the control of the driving module 41, so that when the delivery pipe 52 needs to be cooled, the cold head 22 is sequentially connected to the second heat-conducting member 32, the first heat-conducting member 31 and the cold trap 51, and when heating is required, the first heat-conducting member 31 and the second heat-conducting member 32 are separated.
[0018] In order to improve the heat transfer effect and working reliability, the atmospheric pre-concentrator further comprises: A third heat conductor 33 and a fourth heat conductor 34, wherein the third heat conductor 33 is disposed between the cold head 22 and the second heat conductor 32, and the fourth heat conductor 34 is connected to the second heat conductor 32; the driving module 41 drives the fourth heat conductor 34 so that the fourth heat conductor 34 is selectively connected to or separated from the first heat conductor 31.
[0019] like Figure 2As shown, in order to improve the reliability of connection and separation between the first heat conducting member 31 and the second heat conducting member 32, further, the upper side of the fourth heat conducting member 34 has a cylindrical member 35; like Figure 3 As shown, the driving module 41 includes a driving rod 42 , one end of which is located in the cylindrical component 35 , and a rotating shaft passes through the one end and is disposed on the cylindrical component 35 .
[0020] In order to reduce structural complexity and improve reliability, further, one end of the second heat-conducting member 32 is fixed on the cold head 22, the driving module 41 is a cylinder, and the driving lever 42 is connected to the piston.
[0021] In order to improve the cooling efficiency and the heating efficiency, the shell 11 is further a closed cavity with a vacuum inside.
[0022] In order to reduce the difficulty of moving the fourth heat-conducting member 34 , further, the portion of the second heat-conducting member 32 that faces the cold head 22 is arc-shaped.
[0023] In order to improve the cooling efficiency, a heat insulating component 81 is further provided between the driving module 41 and the second heat conducting member 32 .
[0024] In order to increase the contact area, further, the first heat conducting member 31 , the third heat conducting member 33 and the fourth heat conducting member 34 are all flat plate structures.
[0025] The working method of the atmospheric pre-concentrator in this embodiment is specifically as follows: When the cold trap 51 needs to be refrigerated, under the drive of the driving module 41, the second heat conducting member 32 is connected to the first heat conducting member 31, so that the refrigerator 21 is connected to the cold head 22, the second heat conducting member 32, the first heat conducting member 31 and the cold trap 51 in sequence; When the cold trap 51 needs to be heated, the second heat conducting member 32 is separated from the first heat conducting member 31 under the drive of the driving module 41 , and the heating module 71 heats the cold trap 51 .
[0026] Example 2.
[0027] An application example of the atmospheric pre-concentrator and method in Example 1 of the present invention.
[0028] In this application example, Figure 1As shown, the shell 11 is evacuated. The refrigerator 21 is arranged outside the shell and connected to the cold head 22 in the shell 11. The third heat conductor 33 is fixed on the upper side of the cold head 22, the upper end of the third heat conductor 33 is fixedly connected to one end of the second heat conductor 32, and the other end is fixedly connected to the fourth heat conductor 34, and the upper side of the fourth heat conductor 34 has a cylindrical part 35. The first heat conductor 31 is connected to the cold trap 51. The transmission pipe 52 is a stainless steel pipe, connecting the heating module 71 and the cold trap 51. The first heat conductor 31 is fixed to the bottom wall of the shell 11 through a stainless steel column.
[0029] like Figure 2 As shown, the second heat conducting member 32 is made of copper bars, with a width of 15 mm, a thickness of 0.2 mm, and 15 pieces, and the part facing the third heat conducting member 33 is arc-shaped. The first heat conducting member 31, the third heat conducting member 33, and the fourth heat conducting member 34 are made of aluminum alloy and are in the shape of a flat plate. The side of the first heat conducting member 31 has a notch.
[0030] like Figure 3 As shown, the driving module 41 adopts a cylinder, the cylinder body is arranged outside the housing 11, and the driving rod 42 is connected to the piston. One end of the driving rod 42 enters the housing 11, passes through the notch and the fourth heat-conducting member 34, and enters the tubular component 35. The rotating shaft passes through one end of the driving rod 42 and is arranged on the tubular component 35. A heat insulating component 81 is arranged between the driving rod 42 and the tubular component 35, and the rotating shaft is made of a heat insulating material. The driving rod 42 and the housing 11 are kept sealed.
[0031] The working method of the atmospheric pre-concentrator in this embodiment is specifically as follows: When the cold trap 51 needs to be cooled, the cylinder drives the driving rod 41 to move downward, so that the fourth heat-conducting member 34 contacts the first heat-conducting member 31, specifically, in a plane contact, so that the refrigerator 21 sequentially connects the cold head 22, the third heat-conducting member 33, the second heat-conducting member 32, the fourth heat-conducting member 34, the first heat-conducting member 31 and the cold trap 51; When the cold trap 51 needs to be heated, the cylinder drives the driving rod 41 to move upward, the fourth heat conducting member 34 is separated from the first heat conducting member 31 , and the heating module 71 heats the cold trap 51 .
[0032] Example 3.
[0033] According to the application example of the atmospheric pre-concentrator and method in Example 1 of the present invention, the difference from Example 2 is that: Use a lead screw driven by a motor instead of a cylinder.
Claims
1. An atmospheric pre-concentrator, comprising a delivery pipe, a cold trap, a refrigerator and a heating module; characterized in that: The atmospheric pre-concentrator also includes: A shell and a cold head, wherein the delivery pipe is arranged in the shell, and the cold head is arranged in the shell and connected to the refrigerator; a first heat conducting member, the first heat conducting member being connected to the cold trap; A second heat-conducting member and a driving module, wherein one end of the second heat-conducting member is connected to the cold head, and the other end is selectively connected to or separated from the first heat-conducting member under the control of the driving module.
2. The atmospheric pre-concentrator according to claim 1, characterized in that: The atmospheric pre-concentrator also includes: A third heat-conducting member and a fourth heat-conducting member, wherein the third heat-conducting member is arranged between the cold head and the second heat-conducting member, and the fourth heat-conducting member is connected to the second heat-conducting member; and the driving module drives the fourth heat-conducting member so that the fourth heat-conducting member is selectively connected to or separated from the first heat-conducting member.
3. The atmospheric pre-concentrator according to claim 2, characterized in that: The fourth heat-conducting member has a cylindrical component on its upper side; The driving module comprises a driving rod, one end of which is located in the cylindrical component, and a rotating shaft passes through the one end and is arranged on the cylindrical component.
4. The atmospheric pre-concentrator according to claim 3, characterized in that: One end of the second heat-conducting member is fixed on the cold head, the driving module is a cylinder, and the driving lever is connected to a piston.
5. The atmospheric pre-concentrator according to claim 1, characterized in that: The shell is a closed cavity with a vacuum inside.
6. The atmospheric pre-concentrator according to claim 1, characterized in that: The portion of the second heat conducting member facing the cold head is arc-shaped.
7. The atmospheric pre-concentrator according to claim 1, characterized in that: A heat insulating component is arranged between the driving module and the second heat conducting component.
8. The atmospheric pre-concentrator according to claim 1, characterized in that: The first heat conducting member, the third heat conducting member and the fourth heat conducting member are all flat plate structures.
9. The working method of the atmospheric pre-concentrator according to claim 1, specifically: When the cold trap needs to be refrigerated, under the drive of the driving module, the second heat-conducting member is connected to a heat-conducting member, so that the refrigerator is sequentially connected to the cold head, the second heat-conducting member, the first heat-conducting member and the cold trap; When the cold trap needs to be heated, the second heat-conducting member is separated from the first heat-conducting member under the driving of the driving module, and the heating module heats the cold trap.