gas chromatograph

Abstract

A gas chromatograph (1) comprises: a gas chromatograph body (2) having an internal space (12) that is thermally insulated from the exterior; at least one sample vaporizer (4) mounted on an upper part of the gas chromatograph body (2), the sample vaporizer (4) having a casing (18), a heating space (22) surrounded by a heater (20) being formed in the casing (18), the sample vaporizer (4) vaporizing a sample injected into the heating space (22) with heat from the heater (20) and introducing the vaporized sample into the gas chromatograph body (2); and at least one cooling fan (10) mounted on top of the gas chromatograph body (2) in a manner corresponding to each of the at least one sample vaporizer (4), each cooling fan (10) sending a cooling airflow to a respective one of the at least one sample vaporizer (4). A thermally insulating member (38; 40) is interposed between the gas chromatograph body (2) and each of the at least one cooling fan (10), and each of the at least one cooling fan (10) is thermally isolated from the gas chromatograph body (2).

Description

Technical Field

[0001] The present invention relates to a gas chromatograph (hereinafter referred to as GC).

Background Art

[0002] As one of the sample injection methods of GC, there is cold on-column injection (hereinafter referred to as OCI). OCI is a method in which after directly injecting a sample into a column, the temperature inside the sample vaporization section is rapidly increased to about 450°C, and the sample is vaporized inside the column.

[0003] OCI is often used when analyzing samples with high boiling points, and the analysis time tends to be longer compared to when using injection methods other than OCI. Therefore, in order to shorten the total analysis time when performing continuous analysis using OCI, it is important to lower the temperature of the sample vaporization section as quickly as possible after the sample elutes from the column and to bring it to a state where the analysis of the next sample can be started. For this reason, countermeasures such as installing a cooling fan near the sample vaporization section and cooling the sample vaporization section with the cooling fan have been taken (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0006] This invention has been made in view of the above problems, and aims to suppress failure and deterioration of cooling fans caused by continuous analysis over long periods of time. [Means for solving the problem]

[0007] The gas chromatograph according to the present invention comprises a gas chromatograph body whose internal space is thermally isolated from the outside; at least one sample vaporization unit mounted on top of the gas chromatograph body, having a housing, the housing having a heating space surrounded by a heater formed inside, which vaporizes a sample injected into the heating space by heat from the heater and introduces it into the gas chromatograph body; and at least one cooling fan mounted on the gas chromatograph body corresponding to each of the at least one sample vaporization units, each blowing cooling air toward each of the at least one sample vaporization units, wherein an insulating member is interposed between the gas chromatograph body and each of the at least one cooling fan, so that each of the at least one cooling fan is thermally isolated from the gas chromatograph body. [Effects of the Invention]

[0008] According to the gas chromatograph of the present invention, an insulating material is interposed between the gas chromatograph body and the cooling fan, and the cooling fan is thermally isolated from the gas chromatograph body, thereby suppressing failure or deterioration of the cooling fan caused by continuous analysis over long periods of time. [Brief explanation of the drawing]

[0009] [Figure 1] This is a partial cross-sectional view showing one embodiment of a gas chromatograph. [Figure 2] This figure shows another example of the cooling structure in the same embodiment. [Figure 3] This is a top-down layout diagram showing an example of the arrangement of cooling fans when two sample vaporization units are installed. [Modes for carrying out the invention]

[0010] An embodiment of a gas chromatograph will be described below with reference to the drawings.

[0011] The gas chromatograph 1 (hereinafter referred to as GC1) comprises a gas chromatograph body 2 (hereinafter referred to as GC body 2), a sample vaporization unit 4, a detector 6, an injector 8, and a cooling fan 10. The sample vaporization unit 4, detector 6, injector 8, and cooling fan 10 are mounted on the top of the GC body 2.

[0012] The internal space 12 of the GC body 2 is surrounded by an insulating material 14, and is thermally isolated from the outside of the GC body 2. The column 16 for separating components in the sample gas is housed in the internal space 12 of the GC body 2. One end of the column 16 is connected to the sample vaporization section 4, and the other end is connected to the detector 6.

[0013] The sample vaporization unit 4 has a housing 18, and a heating space 22 surrounded by a heater 20 is formed inside the housing 18. A cylindrical insert 24 is placed in the heating space 22 inside the housing 18 of the sample vaporization unit 4, and one end of the column 16 is inserted into the inside of the insert 24 from below. A septum 26 is provided at the top of the sample vaporization unit 4, and the upper part of the heating space 22 is sealed by the septum 26. The cap 27 that holds the septum 26 is provided with a sample injection port 28, which is a through hole for guiding the needle of the syringe 34 of the injector 8 into the heating space 20. In addition, an intake port 30 for taking in cooling air and an exhaust port 32 for exhausting the air inside the housing 18 to the outside are provided on opposite sides of the housing 18 of the sample vaporization unit 4.

[0014] The injector 8 is configured to draw in a sample from a sample container (not shown) by moving a syringe 34 up and down, insert a needle through the sample inlet 28 into the heated space 22 in the sample vaporization section 4, and inject the sample into the column 16.

[0015] The cooling fan 10 is positioned to the side of the sample vaporization unit 4 to send cooling air toward the intake port 30 of the sample vaporization unit 4. The cooling fan 10 is supported by a metal support member 36 attached to the top plate 15 of the GC body 2. In this embodiment, heat insulating members 38 and 40 are sandwiched between the support member 36 and the cooling fan 10, and between the top plate 15 of the GC body 2 and the support member 36, respectively, thereby suppressing the transfer of heat from the GC body 2 to the cooling fan 10. Examples of materials for the heat insulating members 38 and 40 include PTFE (polytetrafluoroethylene), ceramic materials, Viton materials, and nitrile materials.

[0016] Furthermore, any configuration that can suppress the transfer of heat from the GC body 2 to the cooling fan 10 is sufficient. Only one of the heat insulating members 38 and 40 may be provided, or the support member 36 itself may be a heat insulating member made of a heat insulating material. In short, it is sufficient that a heat insulating member is interposed between the GC body 2 and the cooling fan 10. In addition, in this embodiment, a structure such as a duct for efficiently guiding the cooling air generated by the cooling fan 10 into the sample vaporization unit 4 is not provided between the sample vaporization unit 4 and the cooling fan 10, but such a structure can also be provided.

[0017] Figure 2 shows an example where the height of the support member 36 supporting the cooling fan 10 is lower than in Figure 1, bringing the cooling fan 10 closer to the top plate 15 of the GC body 2. In this way, even when the cooling fan 10 is brought closer to the top plate 15 of the GC body 2, the presence of the heat insulating member 40 between the GC body 2 and the cooling fan 10 suppresses the transfer of heat from the GC body 2 to the cooling fan 10, preventing the temperature of the cooling fan 10 from exceeding its heat resistance temperature. By positioning the cooling fan 10 lower than in Figure 1, as shown in Figure 2, cooling air can be supplied to the sample vaporization section 4 from a lower position. Furthermore, by positioning the exhaust port 32 of the sample vaporization section 4 higher than the intake port 30, heat inside the sample vaporization section 4 can be efficiently released to the outside, improving the cooling efficiency inside the sample vaporization section 4.

[0018] As described above, by interposing an insulating material between the GC body 2 and the cooling fan 10, the height at which the cooling fan 10 is installed can be freely designed. Therefore, when installing multiple cooling fans 10, the heights of the cooling fans 10 can be made different from each other, thereby reducing the area occupied by the multiple cooling fans 10 on the GC body 2.

[0019] FIG. 3 is a layout view seen from above showing an example of the arrangement of two cooling fans 10A and 10B corresponding to two sample vaporization units 4A and 4B when two sample vaporization units 4A and 4B are mounted on the GC main body 2. In this example, the cooling fans 10A and 10B are arranged at different positions from each other so that a part of each overlaps vertically with the other. As a result, the sample vaporization units 4A and 4B can be arranged close to each other, contributing to the miniaturization of the GC main body 2.

[0020] The embodiments described above are merely examples of embodiments of the gas chromatograph according to the present invention. The embodiments of the gas chromatograph according to the present invention are as follows.

[0021] In one embodiment of the gas chromatograph according to the present invention, there are provided a gas chromatograph main body whose internal space is thermally insulated from the outside, at least one sample vaporization unit mounted on the upper part of the gas chromatograph main body, having a housing, and a heating space surrounded by a heater inside the housing, for vaporizing a sample injected into the heating space by heat from the heater and introducing it into the gas chromatograph main body, and at least one cooling fan mounted on the gas chromatograph main body so as to correspond to each of the at least one sample vaporization unit, each of which blows cooling air toward each of the at least one sample vaporization unit, and a heat insulating member is interposed between each of the gas chromatograph main body and each of the at least one cooling fan so that each of the at least one cooling fan is thermally separated from the gas chromatograph main body.

[0022] In the first aspect of the above embodiment, at least a part of each of the support members for supporting each of the at least one cooling fan on the gas chromatograph main body serves as the heat insulating member.

[0023] In the second aspect of the above-described embodiment, only one sample vaporization unit is provided, and the sample vaporization unit includes an intake port for taking in the cooling air blown by the cooling fan into the housing, and an exhaust port for exhausting the air inside the housing is provided at a position higher than the intake port. The cooling fan is provided to blow the cooling air toward the intake port of the housing of the sample vaporization unit. With such an aspect, the cooling efficiency in the sample vaporization unit can be improved.

[0024] In the third aspect of the above-described embodiment, two or more sample vaporization units are provided, and each of the sample vaporization units has intake ports for taking in the cooling air blown by the cooling fan into the housing at different heights. The cooling fans corresponding to each of the sample vaporization units are provided at different heights so as to blow the cooling air to the corresponding intake ports of the corresponding sample vaporization units. With such an aspect, a plurality of cooling fans can be arranged such that a part of each other overlaps vertically, so that the installation area of the plurality of cooling fans can be reduced, and as a result, the gas chromatograph can be miniaturized.

[0025] In the fourth aspect of the above-described embodiment, the sample vaporization unit is a sample vaporization unit for cold on-column injection.

Explanation of symbols

[0026] 1 GC 2 GC main body 4, 4A, 4B Sample vaporization unit 6 Detector 8 Injector 10, 10A, 10B Cooling fan<0 / sup> 12 Internal space 14 Heat insulating material 15 Top plate of GC main body 16 Column 18 Housing of sample vaporization unit 20 Heater 22 Heating space 24 Insert 26 Septum 28 Sample Inlet 30 Intake 32 Exhaust vents 34 Syringes 36 Support Member 38, 40 Insulation material

Claims

1. A gas chromatograph body having an internal space, an insulating material that surrounds the internal space and thermally isolates the internal space from the outside, and a top plate located on the upper surface of the insulating material, A sample vaporization unit is mounted on the top plate of the gas chromatograph body, has a housing, and has a heating space enclosed by a heater inside the housing, which vaporizes a sample injected into the heating space by heat from the heater and introduces it into the gas chromatograph body. A thermal insulation member is provided separately from the thermal insulation material at a location on the top plate of the gas chromatograph body, separate from the location where the sample vaporization unit is mounted. The system includes a cooling fan mounted on the aforementioned heat insulating member, which blows cooling air toward the sample vaporization section, A gas chromatograph in which the insulating member is interposed between the gas chromatograph body and the cooling fan, thereby thermally separating the cooling fan from the gas chromatograph body.

2. Further comprising a metal support member provided on the heat insulating member, The gas chromatograph according to claim 1, wherein the cooling fan is mounted on the support member.

3. The sample vaporization unit is provided with an intake port for taking in cooling air blown by the cooling fan into the housing, and an exhaust port for exhausting the air inside the housing is provided at a position higher than the intake port, The gas chromatograph according to claim 1, wherein the cooling fan is provided to blow cooling air toward the intake port of the housing of the sample vaporization unit.

4. The sample vaporization section is provided with two or more units, and the cooling fan is provided with two or more units corresponding to each of the sample vaporization sections. Each of the sample vaporization units is provided with intake ports at different heights for drawing in cooling air blown by the cooling fan into the housing, The gas chromatograph according to claim 1, wherein the cooling fans corresponding to each of the sample vaporization sections are provided at different heights to blow cooling air to the intake port of the corresponding sample vaporization section.

5. The gas chromatograph according to claim 1, wherein the sample vaporization unit is a sample vaporization unit for cold on-column injection.

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