WO2018207258A1

WO2018207258A1 - Gas chromatograph

Info

Publication number: WO2018207258A1
Application number: PCT/JP2017/017546
Authority: WO
Inventors: 優輝小森; 茂暢中野; 昌之岡田
Original assignee: 株式会社島津製作所
Priority date: 2017-05-09
Filing date: 2017-05-09
Publication date: 2018-11-15
Also published as: CN110621994A; JPWO2018207258A1; CN110621994B; JP6863457B2

Abstract

This gas chromatograph 1 is provided with a cooling device 8. The cooling device 8 comprises an inner supply pipe 83. The inner supply pipe 83 extends to the vicinity of a region, in which a column 2 is arranged, within a column oven 3. A coolant which is supplied from an external supply pipe 81 toward the inside of the column oven 3 flows into the inner supply pipe 83, and is subsequently ejected into the column oven 3 through an ejection port 83A. At this time, the inside of the column oven 3 is cooled by means of the inner supply pipe 83, which internally contains the coolant, and is further cooled by means of the coolant that is supplied into the column oven 3 through the inner supply pipe 83. In this manner, the inside of the column oven 3 is cooled in stages by means of the inner supply pipe 83 itself and the coolant which is supplied from the inner supply pipe 83. Consequently, the temperature within the column oven 3 is able to be controlled with high accuracy by means of the cooling device 8.

Description

Gas chromatograph

The present invention relates to a gas chromatograph provided with a cooling device for cooling the inside of a column oven.

Conventionally, a gas chromatograph equipped with a cooling device that introduces a refrigerant into the column oven and cools the inside of the column oven to a predetermined temperature has been used. In the gas chromatograph, the analysis operation is performed, so that the inside of the column oven is heated by the heater to be in a high temperature state. Thereafter, for the next measurement, the inside of the column oven is cooled to a predetermined temperature by the cooling device. As described above, in the gas chromatograph, the inside of the column oven is appropriately cooled by the cooling device, and the analysis operation is repeatedly performed (for example, see Patent Document 1 below).

In the gas chromatograph described in Patent Document 1 below, a cooling gas supply pipe (supply line) is connected to a column oven. The supply pipe is provided with a valve for adjusting the supply amount of the cooling gas. Then, by appropriately opening the valve, the cooling gas is introduced into the column oven through the supply pipe, and the inside of the column oven is cooled.

Japanese Patent Laid-Open No. 11-44680

The conventional gas chromatograph described above has a problem that the temperature is difficult to stabilize when the inside of the column oven is cooled.

Specifically, in the above gas chromatograph, a sensor for detecting the temperature in the column oven is provided. Based on the temperature in the column oven detected by the sensor, cooling is performed in the column oven through the supply pipe. Gas is introduced. In this way, in the cooling device configured to cool the inside of the column oven only by the cooling gas introduced into the interior, the cooling gas is introduced until the ambient temperature around the sensor decreases due to the influence of the gas. There is a time lag between them.

For example, even when a necessary amount of gas is introduced into the column oven, immediately after the gas is introduced, the ambient temperature around the sensor does not decrease completely (is not stable). Therefore, if gas is continuously introduced into the column oven based on the detection temperature of the sensor, more gas than necessary is introduced into the column oven when the detection temperature of the sensor reaches the target temperature. As a result, even if the gas supply is stopped thereafter, the ambient temperature around the sensor is further lowered, and finally it is greatly lowered from the target temperature. Thus, in the configuration of the gas chromatograph described above, there arises a problem that the internal temperature is difficult to stabilize.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a gas chromatograph capable of accurately adjusting the temperature in a column oven.

(1) A gas chromatograph according to the present invention includes a column oven and a cooling device. The column oven contains a column therein. The cooling device cools the inside of the column oven by discharging a refrigerant from the discharge port into the column oven. The cooling device includes a supply pipe that extends to the vicinity of a region where the column is arranged in the column oven and supplies a refrigerant to the discharge port.

According to such a configuration, the inside of the column oven is cooled by the supply pipe containing the refrigerant therein. And the inside of a column oven is further cooled by supplying a refrigerant | coolant in a column oven via a supply pipe | tube. That is, the inside of the column oven is cooled in stages by the supply pipe itself and the refrigerant supplied from the supply pipe.
Therefore, the temperature inside the column oven can be accurately controlled by the cooling device.

(2) The gas chromatograph may further include a heater. The heater is provided in the column oven and heats the column oven. The supply pipe may extend to a region between the heater and the column.

According to such a configuration, the region between the heater and the column can be cooled by the supply pipe containing the refrigerant inside.

(3) Further, the supply pipe may be formed in a curved shape in the vicinity of a region where the column is arranged.

According to such a configuration, the atmosphere around the column can be efficiently cooled by the supply pipe containing the refrigerant inside.

(4) Moreover, the said supply pipe | tube may be formed in the curved shape corresponding to the shape of the said column.

According to such a configuration, the column itself can be efficiently cooled by the supply pipe containing the refrigerant inside.

(5) The cooling device may include a resistance pipe having a resistance portion having an inner diameter smaller than that of the supply pipe and communicating with the supply pipe on the upstream side of the supply pipe.

According to such a configuration, after passing through the resistance portion, the refrigerant passes through the supply pipe and is supplied into the column oven. Therefore, even if the supply pressure of the refrigerant is large, the flow rate can be adjusted by passing the resistance portion.

(6) The gas chromatograph may further include a switching unit. The switching unit switches to a first supply state in which the refrigerant is supplied to the supply pipe via the resistance unit, or a second supply state in which the refrigerant is supplied to the supply pipe without going through the resistance unit.

According to such a configuration, the refrigerant can be supplied into the column oven in an appropriate supply state (supply path) by appropriately switching the supply state by the switching unit.

(7) Further, the cooling device may include a flow rate adjusting valve. The flow rate adjusting valve adjusts the flow rate of the refrigerant supplied to the supply pipe on the upstream side of the supply pipe.

According to such a configuration, the flow rate of the refrigerant can be adjusted by the resistance portion after the flow rate of the refrigerant is adjusted by the flow rate adjusting valve.
Therefore, the flow rate of the refrigerant can be adjusted appropriately.

According to the present invention, the inside of the column oven is cooled in stages by the supply pipe itself and the refrigerant supplied from the supply pipe. Therefore, the temperature inside the column oven can be accurately controlled.

It is the schematic which showed the structural example of the gas chromatograph which concerns on 1st Embodiment of this invention. It is the front view which showed the internal supply pipe | tube used for the cooling device of FIG. It is the front view which showed the internal supply pipe | tube used for the cooling device of the gas chromatograph which concerns on 2nd Embodiment of this invention. It is the schematic which showed the structural example of the gas chromatograph which concerns on 3rd Embodiment of this invention.

1. Configuration of Gas Chromatograph FIG. 1 is a schematic diagram showing a configuration example of a gas chromatograph 1 according to the first embodiment of the present invention.

The gas chromatograph 1 is for performing analysis by supplying a sample gas together with a carrier gas into the column 2. The container 7 and the cooling device 8 are provided.
The column 2 is accommodated in the column oven 3. The column 2 is composed of, for example, a capillary column.
The column oven 3 is formed in a box shape.

The heater 4 is for heating the inside of the column oven 3 and is arranged in the column oven 3. The heater 4 is disposed at a distance from the column 2. In the column oven 3, a partition plate 9 is provided between the column 2 and the heater 4. The partition plate 9 is formed with a hole through which air passes and a hole through which a part of the cooling device 8 is inserted.

The fan 5 is disposed in the column oven 3. The fan 5 is provided on the opposite side of the column 2 with respect to the heater 4. In the gas chromatograph 1, the side on which the fan 5 is provided is the rear side, and the side on which the column 2 is provided is the front side.

The sample introduction unit 6 is for introducing a carrier gas and a sample gas into the column 2, and a sample vaporizing chamber (not shown) is formed therein. A liquid sample is injected into the sample vaporization chamber, and the sample vaporized in the sample vaporization chamber is introduced into the column 2 together with the carrier gas. A gas supply channel 11 and a split channel 12 communicate with the sample vaporizing chamber.
The gas supply channel 11 is a channel for supplying a carrier gas into the sample vaporization chamber of the sample introduction unit 6.

When the carrier gas and the sample gas are introduced into the column 2 by the split introduction method, the split flow path 12 is configured so that a part of the gas in the sample vaporization chamber (mixed gas of the carrier gas and the sample gas) is externally supplied at a predetermined split ratio. This is a flow path for discharging the water.

The detector 7 is composed of, for example, a flame ionization detector (FID) or a flame photometric detector (FPD). The detector 7 sequentially detects each sample component contained in the carrier gas introduced from the column 2.

The cooling device 8 is a device for cooling the inside of the column oven 3 by discharging a refrigerant into the column oven 3. The refrigerant discharged from the cooling device 8 is, for example, a cooling gas such as N2 gas or CO2 gas. A part of the cooling device 8 is disposed in the column oven 3. The detailed configuration of the cooling device 8 will be described later.

When a sample is measured in the gas chromatograph 1, first, the temperature in the column oven 3 is lowered to a set temperature (room temperature or lower) using the cooling device 8. In this state, a sample to be analyzed is injected into the sample introduction unit 6. The sample is vaporized in the sample vaporization chamber. A carrier gas is supplied to the sample vaporization chamber of the sample introduction unit 6 via the gas supply channel 11.

The sample vaporized in the sample vaporization chamber is introduced into the column 2 together with the carrier gas. After the sample is introduced into the column 2, the heater 4 and the fan 5 are driven to heat the inside of the column oven 3, thereby gradually increasing the temperature in the column oven 3. Each sample component contained in the sample is separated in the process of passing through the column 2 and sequentially introduced into the detector 7.

The detector 7 sequentially detects each sample component contained in the carrier gas introduced from the column 2. In the gas chromatograph 1, a chromatogram is generated based on the detection signal of the detector 7. The user confirms the obtained chromatogram and performs various analyses. After confirmation of the chromatogram, the inside of the column oven 3 is cooled to the initial temperature by discharging hot air out of the system.

Thereafter, the refrigerant is discharged from the cooling device 8 into the column oven 3. Thereby, the inside of the column oven 3 is cooled to a predetermined temperature (target temperature). Then, the above analysis operation is repeated. As described above, in the gas chromatograph 1, when the analysis operation is repeatedly performed, the temperature control by the cooling device 8 is appropriately performed.

2. Configuration of Cooling Device The cooling device 8 includes a flow rate adjusting valve 80, an external supply pipe 81, a resistance pipe 82, and an internal supply pipe 83.
The flow rate adjustment valve 80 is provided on the side wall (rear wall) of the column oven 3. The flow rate adjusting valve 80 is a valve for adjusting the flow rate of the refrigerant. An external supply pipe 81 and a resistance pipe 82 are connected to the flow rate adjusting valve 80. That is, the flow rate adjusting valve 80 is interposed between the external supply pipe 81 and the resistance pipe 82. The opening degree of the flow rate adjusting valve 80 is adjusted by a control unit (not shown). Note that the flow rate adjusting valve 80 may be configured so that its opening degree is manually adjusted.

The external supply pipe 81 is disposed outside the column oven 3. The external supply pipe 81 has a downstream end connected to the flow rate adjusting valve 80. Although not shown, the upstream end of the external supply pipe 81 is connected to a reservoir such as a cylinder in which the refrigerant is stored. And a refrigerant | coolant is supplied from this storage part.

The resistance tube 82 is disposed inside the column oven 3. The resistance tube 82 has an upstream end connected to the flow rate adjusting valve 80. The resistance tube 82 is a tubular member having a flow path resistance corresponding to its length. The inner diameter of the resistance tube 82 is smaller than the inner diameter of the internal supply tube 83. As will be described later, the resistance tube 82 is a detachable member. The resistance tube 82 is an example of a resistance portion.

The internal supply pipe 83 is disposed inside the column oven 3. Specifically, the internal supply pipe 83 is disposed (extends) in a region between the column 2 and the heater 4, and more specifically, between the column 2 and the partition plate 9. It is arranged (extends). The internal supply pipe 83 is an example of the supply pipe.
FIG. 3 is a front view showing the internal supply pipe 83.
The internal supply pipe 83 is formed in a curved shape (arc shape). The internal supply pipe 83 includes a tubular portion 831 and a connection portion 832.

The tubular portion 831 is formed in a tubular shape. The tubular portion 831 is curved in an arc shape from the upstream end portion to the central portion, and a portion from the central portion (slightly downstream portion from the central portion) to the downstream end portion is linearly extended. . That is, the tubular portion 831 includes a portion formed in an arc shape and a portion formed in a straight line shape. The inner space of the downstream end portion (the tip portion of the straight portion) of the tubular portion 831 is the discharge port 83A. A central portion of the tubular portion 831 is held by the fixing member 20. A connection portion 832 is attached to the upstream end portion of the tubular portion 831.

The connecting portion 832 is formed in a cylindrical shape. The internal space of the connection portion 832 communicates with the internal space of the tubular portion 831. The distal end portion (upstream end portion) of the connection portion 832 has a configuration in which the resistance tube 82 can be attached.

Although not shown in FIG. 1, the fixing member 20 is attached to the partition plate 9. The internal supply pipe 83 (tubular portion 831) is held by the fixing member 20. Thereby, the internal supply pipe 83 is held in a state of being arranged between the partition plate 9 and the column 2. In this state, the downstream end portion of the internal supply pipe 83 is disposed at a lower portion in the column oven 3. Further, the discharge port 83A of the internal supply pipe 83 is oriented in the horizontal direction. Thereby, the refrigerant discharged from the discharge port 83 </ b> A is not directly injected onto the column 2, but hits the inner wall of the column oven 3 and diffuses.

The internal supply pipe 83 is provided in the vicinity of the region where the column 2 is arranged in a state where it is held in the column oven 3. Specifically, the internal supply pipe 83 is disposed behind the column 2 with a space therebetween. The shape of the internal supply pipe 83 corresponds to the shape of the column 2. Specifically, the size of the outer shape of the internal supply pipe 83 is approximately the same as the size of the outer shape of the column 2, and the internal supply pipe 83 and the column 2 overlap when viewed in the front-rear direction.

3. Operation of Cooling Device In the gas chromatograph 1, a resistance tube 82 having an appropriate length (resistance tube 82 having an appropriate flow path resistance) corresponding to the usage state of the gas chromatograph 1 is selected, and the resistance tube 82 is used.

For example, when the remaining amount of the refrigerant is large, the supply pressure of the refrigerant increases, so that the supply amount increases even if the flow rate adjustment valve 80 has the same opening degree. In such a case, the user selects a resistance tube 82 having a long length (large flow path resistance), and connects the resistance tube 82 to the internal supply tube 83 and the flow rate adjusting valve 80. Further, for example, when the remaining amount of the refrigerant is small, the supply pressure of the refrigerant becomes small. Therefore, in such a case, the user selects a resistance tube 82 having a short length (low flow path resistance) and connects the resistance tube 82 to the internal supply tube 83 and the flow rate adjustment valve 80.

The resistance pipe 82 has a downstream end connected to the connection portion 832 of the internal supply pipe 83 and an upstream end connected to the flow rate adjusting valve 80. Thereby, the resistance pipe 82 and the internal supply pipe 83 communicate with each other through the connection portion 832, and the resistance pipe 82 and the external supply pipe 81 communicate with each other through the flow rate adjustment valve 80. As described above, the resistance tube 82 is disposed on the upstream side with respect to the internal supply tube 83. Further, the flow rate adjusting valve 80 is arranged on the upstream side with respect to the resistance pipe 82 and the internal supply pipe 83.

When cooling the inside of the column oven 3, the refrigerant is supplied from the external supply pipe 81 toward the inside of the column oven 3. The refrigerant that has passed through the external supply pipe 81 passes through the flow rate adjustment valve 80 and flows into the resistance pipe 82. Then, after passing through the resistance tube 82, the refrigerant flows into the internal supply tube 83, and is then discharged from the discharge port 83 </ b> A to the lower part in the column oven 3.

Thus, after the flow rate is adjusted by the resistance tube 82, the refrigerant is discharged from the discharge port 83A of the internal supply tube 83. The inside of the column oven 3 (column 2) is cooled by the refrigerant. At this time, the inside of the column oven 3 is cooled not only by the refrigerant but also by the internal supply pipe 83 that contains the refrigerant inside. That is, the column oven 3 is cooled in stages by the internal supply pipe 83 and the refrigerant.

In the gas chromatograph 1, when the refrigerant supply pressure is reduced as a result of repeated cooling of the column oven 3 by the cooling device 8, the opening degree of the flow rate adjusting valve 80 is adjusted, and the refrigerant The flow rate is adjusted. Thereby, the flow rate of the refrigerant can be adjusted without changing the type of the resistance tube 82. As described above, in the cooling device 8 of the gas chromatograph 1, the flow rate of the refrigerant is adjusted by the resistance tube 82 and the flow rate adjusting valve 80.

4). Action Effect (1) According to the present embodiment, as shown in FIG. 1, the cooling device 8 of the gas chromatograph 1 includes the internal supply pipe 83. The internal supply pipe 83 extends to the vicinity of the area where the column 2 is arranged in the column oven 3.

Therefore, the inside of the column oven 3 is cooled by the internal supply pipe 83 containing the refrigerant therein, and further cooled by being supplied with the refrigerant through the internal supply pipe 83. That is, the inside of the column oven 3 is cooled in stages by the internal supply pipe 83 itself and the refrigerant supplied from the internal supply pipe 83.
As a result, the inside of the column oven 3 can be accurately controlled by the cooling device 8.

(2) Also, according to the present embodiment, as shown in FIG. 1, the internal supply pipe 83 extends to a region between the heater 4 and the column 2.

Therefore, the region between the heater 4 and the column 2 can be cooled by the internal supply pipe 83 containing the refrigerant inside.

(3) Further, according to the present embodiment, as shown in FIG. 1, the internal supply pipe 83 is formed in a curved shape in the vicinity of the region where the column 2 is disposed.

Therefore, the atmosphere around the column 2 can be efficiently cooled by the internal supply pipe 83 containing the refrigerant inside.

(4) According to the present embodiment, as shown in FIGS. 1 and 2, the internal supply pipe 83 is formed in a curved shape corresponding to the shape of the column 2. Specifically, the size of the outer shape of the internal supply pipe 83 is approximately the same as the size of the outer shape of the column 2, and the internal supply pipe 83 and the column 2 overlap when viewed in the front-rear direction.

Therefore, the column 2 itself can be efficiently cooled by the internal supply pipe 83 containing the refrigerant inside.

(5) According to the present embodiment, as shown in FIG. 1, the cooling device 8 includes the resistance tube 82. The resistance tube 82 is disposed upstream of the internal supply tube 83 and communicates with the internal supply tube 83.

Therefore, the refrigerant supplied through the external supply pipe 81 passes through the resistance pipe 82 and then passes through the supply pipe and is discharged into the column oven 3.
As a result, even if the supply pressure of the refrigerant is large, the flow rate can be adjusted by passing the resistance tube 82.

(6) Moreover, according to this embodiment, as shown in FIG. 1, the cooling device 8 includes the flow rate adjusting valve 80. The flow rate adjusting valve 80 adjusts the flow rate of the refrigerant on the upstream side with respect to the internal supply pipe 83 and the resistance pipe 82.

Therefore, the flow rate of the refrigerant can be adjusted by the resistance tube 82 after the flow rate of the refrigerant is adjusted by the flow rate adjusting valve 80.
As a result, the flow rate of the refrigerant can be adjusted appropriately.

5). Second Embodiment A gas chromatograph 1 according to another embodiment of the present invention will be described with reference to FIGS. 3 and 4. In addition, about the structure similar to 1st Embodiment, description is abbreviate | omitted by using the code | symbol similar to the above.
FIG. 3 is a front view showing an internal supply pipe 85 used in the cooling device 8 of the gas chromatograph 1 according to the second embodiment of the present invention.

In the second embodiment, in the cooling device 8, an internal supply pipe 85 is used instead of the internal supply pipe 83 described above. The internal supply pipe 85 has a shape different from the shape of the internal supply pipe 83 of the first embodiment.
Specifically, the internal supply pipe 85 includes a tubular portion 851 and a connection portion 852.

The tubular portion 851 is formed in a tubular shape and is formed in a spiral shape. Specifically, the tubular portion 851 is curved so as to turn from the upstream end toward the downstream, and is formed in a shape that becomes farther from the center as it goes downstream. The downstream end of the tubular portion 851 extends linearly downward. An inner space of the downstream end portion (the tip portion of the straight portion) of the tubular portion 851 is the discharge port 85A. An intermediate portion of the tubular portion 851 is held by the fixing member 20. A connecting portion 852 is attached to the upstream end portion of the tubular portion 851.

The connecting portion 852 is formed in a long cylindrical shape. The internal space of the connecting portion 852 communicates with the internal space of the tubular portion 851. A resistance tube 82 is attached to the distal end portion (upstream end portion) of the connection portion 852.

The fixing member 20 is attached to the partition plate 9 (see FIG. 1) in the column oven 3. Then, the internal supply pipe 85 (tubular portion 851) is held by the fixing member 20. In this state, the discharge port 85A of the internal supply pipe 85 is directed downward. Thereby, the refrigerant discharged from the discharge port 85 </ b> A is not directly injected to the column 2, but hits the bottom wall of the column oven 3 and diffuses.

The internal supply pipe 83 is provided in the vicinity of the region where the column 2 is arranged in a state where it is held in the column oven 3. Specifically, the tubular portion 851 of the internal supply pipe 83 faces the column 2 and is disposed in the column oven 3 along the column 2.

When the refrigerant is supplied from the external supply pipe 81 into the column oven 3, the refrigerant that has passed through the external supply pipe 81 passes through the flow rate adjustment valve 80 and the resistance pipe 82, and then passes through the internal supply pipe 83. It passes through and is discharged toward the bottom wall in the column oven 3 from the discharge port 83A.

Thus, according to the second embodiment, in the cooling device 8, the tubular portion 851 of the internal supply pipe 85 is formed in a spiral shape. Therefore, in the column oven 3, the tubular portion 851 of the internal supply pipe 83 can be disposed along the column 2 so as to face the column 2.
As a result, the column 2 can be efficiently cooled by the internal supply pipe 85.

6). 3rd Embodiment FIG. 4: is the schematic which showed the structural example of the gas chromatograph 1 which concerns on 3rd Embodiment of this invention. The third embodiment is different from the first embodiment in that the supply path of the refrigerant supplied to the internal supply pipe 83 can be changed as appropriate.

Specifically, in the third embodiment, a flow path switching valve 90 and a bypass pipe 91 are provided. Further, the flow rate adjusting valve 80 is provided so as to be interposed slightly upstream of the downstream end of the external supply pipe 81.

The flow path switching valve 90 is interposed at the downstream end of the external supply pipe 81. That is, the flow path switching valve 90 is disposed downstream of the flow rate adjustment valve 80. The upstream end of the resistance tube 82 and the upstream end of the bypass tube 91 are connected to the flow path switching valve 90. The flow path switching valve 90 is a valve that can switch the supply path of the refrigerant supplied to the external supply pipe 81 to one of the resistance pipe 82 and the bypass pipe 91.
The bypass pipe 91 has an inner diameter larger than the inner diameter of the resistance pipe 82, and the flow path resistance is smaller than that of the resistance pipe 82. The downstream end of the bypass pipe 91 is connected to the connection portion 832.

Thereby, by switching the flow path switching valve 90, the refrigerant supplied to the external supply pipe 81 flows into the internal supply pipe 83 via the resistance pipe 82 (first supply state), or the resistance pipe 82. Without passing through the bypass pipe 91, it can be discharged into the column oven 3 through one of the paths (second supply state) that flows into the internal supply pipe 83 through the bypass pipe 91.

Thus, according to the gas chromatograph 1 of the third embodiment, the refrigerant can be supplied into the column oven 3 in an appropriate supply state by appropriately switching the supply state (supply path) by the flow path switching valve 90.
7). Modified example

In the above embodiment, the gas chromatograph 1 has been described on the assumption that the resistance pipe 82 is interposed between the internal supply pipe 83 and the flow rate adjustment valve 80. However, the gas chromatograph 1 may be configured such that the upstream end of the internal supply pipe 83 is connected to the flow rate adjusting valve 80 without providing the resistance pipe 82.

Further, in the above embodiment, the

internal supply pipes

83 and 85 are provided in the vicinity of the column 2, and specifically, are provided in the rear of the column 2 (region between the column 2 and the heater 4). As explained. However, the

internal supply pipes

83 and 85 may be provided in the vicinity of the column 2 and in front of the column 2 (on the side opposite to the heater 4 with respect to the column 2).

DESCRIPTION OF SYMBOLS 1 Gas chromatograph 2 Column 3 Column oven 4 Heater 8 Cooling device 80 Flow control valve 82 Resistance pipe 83 Internal supply pipe 83A Discharge port 85 Internal supply pipe 85A Discharge port 90 Flow path switching valve

Claims

A column oven in which the column is housed,
A cooling device that cools the inside of the column oven by discharging a refrigerant from the outlet into the column oven;
The gas chromatograph, wherein the cooling device includes a supply pipe that extends to the vicinity of a region where the column is arranged in the column oven and supplies a refrigerant to the discharge port.
A heater provided in the column oven for heating the inside of the column oven;
The gas chromatograph according to claim 1, wherein the supply pipe extends to a region between the heater and the column.
The gas chromatograph according to claim 1, wherein the supply pipe is formed in a curved shape in the vicinity of a region where the column is arranged.
The gas chromatograph according to claim 3, wherein the supply pipe is formed in a curved shape corresponding to the shape of the column.
2. The cooling device includes a resistance pipe having a resistance portion having an inner diameter smaller than that of the supply pipe and communicating with the supply pipe on an upstream side with respect to the supply pipe. Gas chromatograph.
A switching unit configured to switch to a first supply state in which the refrigerant is supplied to the supply pipe through the resistance unit, or a second supply state in which the refrigerant is supplied to the supply pipe without going through the resistance unit; The gas chromatograph according to claim 5.
6. The gas chromatograph according to claim 5, wherein the cooling device includes a flow rate adjusting valve for adjusting a flow rate of a refrigerant supplied to the supply pipe on an upstream side of the supply pipe.