Focusing device for preconcentrator

Abstract

The focuser comprises a shell, a refrigerant pipeline, an interlayer sleeve and a sample transmission pipe, the interlayer sleeve is arranged on the sample transmission pipe in a sleeving mode, the interlayer sleeve and the sample transmission pipe are arranged in the refrigerant pipeline, and the refrigerant pipeline is arranged in a cavity defined by the shell; the refrigerant pipeline is further provided with a first branch pipe used for leading refrigerants into the refrigerant pipeline, two pipe openings of the refrigerant pipeline and a pipe opening of the first branch pipe penetrate through the outer wall of the shell, the refrigerant pipeline is provided with a plurality of through holes used for spraying out the refrigerants, and the outer wall of the shell is further provided with a refrigerant outlet communicated with the cavity. The device has the advantages of being simple in structure, low in use cost, capable of achieving efficient utilization of refrigerants and the like.

Description

Technical Field

[0001] This invention mainly relates to the field of gas detection equipment technology, specifically a focusing device for a pre-concentrator. Background Technology

[0002] In VOC pre-concentration instruments, the focuser is a key component, mainly used to perform secondary concentration and focusing of the target compound, so as to introduce the sample into subsequent analytical instruments (such as gas chromatograph) for detection more efficiently. The focuser can replace manual injection needles to ensure the consistency of injection.

[0003] Existing focusing methods for cooling mainly include Stirling cooling, electronic cooling, and refrigerant cooling. Stirling cooling is rarely used due to its high cost. Electronic cooling is limited by power, cooling efficiency, equipment size, noise, and vibration, with a maximum cooling temperature of only -80°C. However, there are hundreds of common VOCs, with boiling points ranging from 120°C to -126°C, making it ineffective for capturing VOCs below their target temperature through low-temperature targeting. Refrigerant cooling can reach -200°C, so current technologies mostly involve spraying refrigerant onto a heat-conducting component to cool the target substance. Effective refrigerant utilization is a challenge for manufacturers, as the refrigerant only provides brief, localized contact with the heat-conducting component, requiring a large and continuous injection to cover it. This large refrigerant input also causes significant temperature fluctuations. After the refrigerant flows down from the heat-conducting component, it is generally discharged directly. The discharged gas contains a large amount of vaporized liquid refrigerant (in a semi-gas, semi-liquid state), resulting in significant waste. Furthermore, the refrigerant is typically liquid nitrogen or liquid helium, which is very expensive, leading to high equipment operating costs and the need for frequent refrigerant tank replacements. How to achieve efficient utilization of refrigerant is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention provides a focusing device for a pre-concentrator that is simple in structure, low in operating cost, and enables efficient utilization of refrigerant.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A focusing device for a pre-concentrator includes a housing, a refrigerant pipe, a partition sleeve, and a sample transfer tube. The partition sleeve is fitted onto the sample transfer tube, and the partition sleeve and sample transfer tube are disposed inside the refrigerant pipe, which is located within a cavity enclosed by the housing. The refrigerant pipe also has a first branch pipe for introducing refrigerant into the refrigerant pipe. The two ports of the refrigerant pipe and the port of the first branch pipe all pass through the outer wall of the housing. The refrigerant pipe has multiple through holes for refrigerant ejection, and the outer wall of the housing also has a refrigerant outlet communicating with the cavity.

[0006] As a further improvement of the present invention: the refrigerant pipe, the partition sleeve and the sample transfer pipe are all U-shaped pipes.

[0007] As a further improvement of the present invention: the two ports of the refrigerant pipeline are connected to the housing through a first sealing assembly.

[0008] As a further improvement of the present invention: the first sealing assembly includes a sealing joint, a first sealing sleeve, and a first sleeve nut. As a further improvement of the present invention, it also includes a tee connector, wherein the first interface of the tee connector is connected to the partition sleeve, the second interface of the tee connector is used to introduce heating gas, the third interface is sealed by a second sealing component, and one end of the sample transfer tube passes through the first interface and the third interface of the tee connector.

[0009] As a further improvement of the present invention: the first interface and the partition sleeve are sealed together by a third sealing assembly.

[0010] As a further improvement of the present invention: the second sealing assembly includes a second sealing sleeve and a second sleeve nut.

[0011] As a further improvement of the present invention: the third sealing assembly includes a third sealing sleeve and a third sleeve nut.

[0012] As a further improvement of the present invention: the sample transfer tube is a capillary metal tube or a quartz tube.

[0013] As a further improvement of the present invention, the partition sleeve has a thin-walled structure.

[0014] Compared with the prior art, the advantages of the present invention are as follows: The focusing device for a pre-concentrator of this invention is designed with a refrigerant pipe and a partition sleeve. A small cavity is formed between the refrigerant pipe and the partition sleeve, which serves as a flow channel for the refrigerant. Due to the small volume of the cavity, only a small amount of refrigerant is needed to fill it. The refrigerant flowing within the cavity can quickly cool the partition sleeve and the sample transfer tube located within the partition sleeve, achieving efficient initial cooling. After flowing into the refrigerant pipe, the refrigerant is sprayed out through multiple through-holes on the refrigerant pipe, forming a mist that can quickly vaporize, carrying away a large amount of heat, reducing the temperature inside the shell, preventing external heat from entering, reducing temperature fluctuations, and achieving secondary cooling. This invention can achieve good cooling effect by consuming very little refrigerant, greatly improving the utilization rate of refrigerant and reducing operating costs. Attached Figure Description

[0015] Figure 1 This is a side view of the present invention in a specific embodiment.

[0016] Figure 2 This is a top view of the present invention in a specific embodiment.

[0017] Figure 3 yes Figure 1 Sectional view at point AA.

[0018] Figure 4 yes Figure 2 Sectional view at point BB.

[0019] Figure 5 This is a perspective view of the refrigerant pipeline in a specific embodiment of the present invention.

[0020] Figure 6 This is a cross-sectional view of the refrigerant pipeline of the present invention installed inside the housing.

[0021] Figure 7 yes Figure 6 Sectional view at point CC.

[0022] Legend: 1. Shell; 2. Refrigerant pipe; 3. Partition sleeve; 4. Sample transfer tube; 5. Chamber; 6. First branch pipe; 7. Through hole; 8. Refrigerant outlet; 9. First sealing assembly; 91. Sealing joint; 92. First sealing ferrule; 93. First ferrule nut; 10. T-joint; 101. First interface; 102. Second interface; 103. Third interface; 11. Second sealing assembly; 111. Second sealing ferrule; 112. Second ferrule nut; 12. Third sealing assembly; 121. Third sealing ferrule; 122. Third ferrule nut. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figures 1 to 7 As shown, this embodiment discloses a focusing device for a pre-concentrator, including a housing 1, a refrigerant pipe 2, a partition sleeve 3, and a sample transfer pipe 4. The partition sleeve 3 is sleeved on the sample transfer pipe 4, and the partition sleeve 3 and the sample transfer pipe 4 are disposed inside the refrigerant pipe 2. The refrigerant pipe 2 is disposed within a chamber 5 enclosed by the housing 1. The refrigerant pipe 2 is also provided with a first branch pipe 6 for refrigerant to enter the refrigerant pipe 2. The two ports of the refrigerant pipe 2 and the port of the first branch pipe 6 all pass through the outer wall of the housing 1. The refrigerant pipe 2 is provided with multiple through holes 7 for refrigerant to be ejected. The outer wall of the housing 1 is also provided with a refrigerant outlet 8 communicating with the chamber 5.

[0025] The focuser for the pre-concentrator in this embodiment is designed with a refrigerant pipe 2 and a partition sleeve 3. A small cavity is formed between the refrigerant pipe 2 and the partition sleeve 3, which serves as a flow channel for the refrigerant. Due to the small volume of the cavity, only a small amount of refrigerant is needed to fill it. The refrigerant flowing within the cavity can quickly cool the partition sleeve 3 and the sample transfer tube 4 located in the partition sleeve 3, achieving efficient initial cooling. After flowing into the refrigerant pipe 2, the refrigerant will be ejected through multiple through holes 7 on the refrigerant pipe 2. The refrigerant will rapidly vaporize to form a mist, carrying away a large amount of heat, reducing the temperature inside the chamber 5 of the shell 1, preventing external heat from entering, reducing temperature fluctuations, and achieving secondary cooling. This invention can achieve a good cooling effect by consuming very little refrigerant, greatly improving the utilization rate of refrigerant and reducing operating costs.

[0026] In this embodiment, the refrigerant pipe 2, the partition sleeve 3, and the sample transfer pipe 4 are all U-shaped pipes. Further, in a preferred embodiment, the refrigerant pipe 2 is a U-shaped metal pipe, with the first branch pipe 6 welded to the U-shaped metal pipe. The two ends of the refrigerant pipe 2 are welded to the outer wall of the shell 1. The U-shaped pipe design can extend the cooling time of the refrigerant on the sample transfer pipe 4 to a certain extent.

[0027] In this embodiment, the sample transfer tube 4 is a capillary metal tube; in other embodiments, the sample transfer tube 4 can be a quartz tube.

[0028] In this embodiment, the two ports of the refrigerant pipeline 2 are connected to the housing 1 via a sealing assembly 9. Further, in a preferred embodiment, the first sealing assembly 9 includes a sealing joint 91, a first sealing sleeve 92, and a first sleeve nut 93. The sealing joint 91 is welded to the housing 1 and communicates with the refrigerant pipeline 2. The partition sleeve 3 is a low-temperature resistant flexible thin-walled tube with a diameter smaller than the refrigerant pipeline 2. The partition sleeve 3 passes through the U-shaped refrigerant pipeline 2. The sealing joint 91 seals the partition sleeve 3 with the housing 1 via the first sealing sleeve 92 and the first sleeve nut 93, ensuring that the refrigerant cannot leak from the sealing joint 91 after entering the refrigerant pipeline 2. The refrigerant entering from the first branch pipe 6 can only flow along the refrigerant pipeline 2 and spray out from the through hole 7 into the chamber 5. During the spraying process, the refrigerant vaporization is accelerated. In this embodiment, a T-shaped connector 10 is also included. The T-shaped connector 10 has a first interface 101 connected to the partition sleeve 3. The second interface 102 of the T-shaped connector 10 is used to introduce heating gas. The third interface 103 is sealed by the second sealing assembly 11. One end of the sample transfer tube 4 passes through the first interface 101 and the third interface 103 of the T-shaped connector 10. The second sealing assembly 11 includes a second sealing sleeve 111 and a second sleeve nut 112.

[0029] In this embodiment, the first interface 101 and the partition sleeve 3 are sealed together by a third sealing assembly 12, which includes a third sealing sleeve 121 and a third sleeve nut 122. The second sealing sleeve 111 and the third sealing sleeve 121 are of different sizes to achieve sealing of pipes of different diameters.

[0030] Heating gas enters through the second port 102. Since the third port 103 is sealed by the second sealing component 11, when the heating gas valve is opened, the refrigerant valve is closed, ensuring that the heating gas enters from one end of the partition sleeve 3. The heating gas flows in one direction and heats the sample transfer tube 4. Since the specific heat capacity of the sample transfer tube 4 is extremely small, it can heat up rapidly, thereby rapidly heating and vaporizing the condensed sample. One end of the sample transfer tube 4 is connected to the pre-concentrator, and the other end is connected to the detector. The sample in the sample transfer tube 4 moves under the drive of the carrier gas and enters the detector.

[0031] Working principle: When the sample enters the sample transfer tube 4, the refrigerant valve is opened, and the refrigerant enters the refrigerant pipe 2 through the first branch pipe 6 and flows along the cavity between the refrigerant pipe 2 and the partition sleeve 3, rapidly cooling the partition sleeve 3 and the sample transfer tube 4, achieving the first efficient cooling; as the refrigerant continues to flow to the through hole 7, the refrigerant will be sprayed out through the through hole 7, and the refrigerant will quickly vaporize to form a mist, carrying away a large amount of heat and reducing the temperature in the chamber 5, achieving the second cooling; when sample detection is required, the heating gas valve is opened. At this time, the refrigerant valve is closed, and the heating gas enters the partition sleeve 3 from the second port 102 of the three-way connector 10, and flows unidirectionally to heat the sample transfer tube 4, so that the condensed and accumulated sample is rapidly heated and vaporized, and the sample enters the detector under the drive of the carrier gas.

[0032] 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 principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A focusing device for a pre-concentrator, characterized in that, The system includes a shell (1), a refrigerant pipe (2), a partition sleeve (3), and a sample transfer pipe (4). The partition sleeve (3) is fitted onto the sample transfer pipe (4). The partition sleeve (3) and the sample transfer pipe (4) are located inside the refrigerant pipe (2). The refrigerant pipe (2) is located inside the chamber (5) enclosed by the shell (1). The refrigerant pipe (2) is also provided with a first branch pipe (6) for refrigerant to enter the refrigerant pipe (2). The two ports of the refrigerant pipe (2) and the port of the first branch pipe (6) all pass through the outer wall of the shell (1). The refrigerant pipe (2) is provided with multiple through holes (7) for refrigerant to be ejected. The outer wall of the shell (1) is also provided with a refrigerant outlet (8) that communicates with the chamber (5).

2. The focusing device for a pre-concentrator according to claim 1, characterized in that, The refrigerant pipe (2), the partition sleeve (3), and the sample transfer pipe (4) are all U-shaped pipes.

3. The focusing device for a pre-concentrator according to claim 1, characterized in that, The two ports of the refrigerant pipe (2) are connected to the housing (1) through the first sealing assembly (9).

4. The focusing device for a pre-concentrator according to claim 3, characterized in that, The first sealing assembly (9) includes a sealing joint (91), a first sealing sleeve (92), and a first sleeve nut (93).

5. The focusing device for a pre-concentrator according to claim 1, characterized in that, It also includes a three-way connector (10), the first interface (101) of the three-way connector (10) is connected to the partition sleeve (3), the second interface (102) of the three-way connector (10) is used to introduce heating gas, the third interface (103) is sealed by the second sealing assembly (11), and one end of the sample transfer tube (4) passes through the first interface (101) and the third interface (103) of the three-way connector (10).

6. The focusing device for a pre-concentrator according to claim 5, characterized in that, The first interface (101) and the partition sleeve (3) are sealed together by the third sealing component (12).

7. The focusing device for a pre-concentrator according to claim 5, characterized in that, The second sealing assembly (11) includes a second sealing sleeve (111) and a second sleeve nut (112).

8. The focusing device for a pre-concentrator according to claim 6, characterized in that, The third sealing assembly (12) includes a third sealing sleeve (121) and a third sleeve nut (122).

9. The focusing device for a pre-concentrator according to any one of claims 1 to 8, characterized in that, The sample transfer tube (4) is a capillary metal tube or a quartz tube.

10. The focusing device for a pre-concentrator according to any one of claims 1 to 8, characterized in that, The partition sleeve (3) has a thin-walled structure.

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