JP5203006B2 - Sample gas collector and gas chromatograph - Google Patents

Description

  The present invention relates to a sample gas collecting apparatus and a gas chromatograph apparatus having a collecting member that collects an introduced sample gas at a low temperature and desorbs the collected sample gas at a high temperature. It is.

  A gas chromatograph apparatus (hereinafter referred to as a GC apparatus) is an apparatus used for detecting a component to be detected such as a volatile organic compound contained in a sample gas such as the atmosphere, and detects a trace amount component contained in the sample gas. Therefore, in addition to a detection device such as a separation column and a detection sensor, a configuration including a collection device for collecting and concentrating a detection target component is generally used.

As shown in FIG. 7 , the GC apparatus 100 proposed in Patent Document 1 includes a carrier gas source 108 such as a gas cylinder that generates a carrier gas for transporting a sample gas component, and a component of the sample gas transported by the carrier gas. , A sample introduction port 101 for introducing a sample gas, a suction pump 104 for sucking the sample gas introduced from the sample introduction port 101 and discharging it from the discharge port 115, and a component to be detected from the sample gas And a valve 105 for selectively connecting the collection tube 102 between the sample inlet 101 and the suction pump 104 or between the carrier gas source 108 and the analyzer 110. , Etc.

In the GC apparatus 100, when collecting (concentrating) the detection target component, the valve 105 is switched so that the collection tube 102 is connected in series between the sample introduction port 101 and the suction pump 104, and the suction pump 104 is collected. As the sample gas is sucked, the sample gas introduced into the sample introduction port 101 flows in the collection tube 102 and the detection target component is collected. When detecting the component to be detected, the valve 105 is switched so that the collection tube 102 is connected in series between the carrier gas source 108 and the analyzer 110, and the carrier gas source 108 generates carrier gas. Then, the component to be detected is transported from the collection tube 102 to the analysis device 110 by the carrier gas, and introduced into the analysis device 110 by flowing in the collection tube 102.
JP 2006-337158 A

  However, the conventional collecting pipe as described above needs to flow a large amount of carrier gas when sending the collected gas component to the analyzer, so that the time required for sending the gas component also increases. There was a problem that the separability deteriorated. Therefore, it has been difficult to improve the concentration rate of the sample gas by the collection tube. In addition, since a large amount of carrier gas is required, it is difficult to reduce the running cost required for the analysis of gas components.

  Therefore, in view of the above-described problems, the present invention provides a sample gas collecting device and a gas chromatograph device capable of improving the separability of collected sample gas and delivering a high concentration sample gas in a short time. It is an issue.

In order to solve the above problems, the sample gas collecting apparatus according to claim 1, which is made according to the present invention, includes an introduction port 11 b for introducing a sample gas and a hollow member 11 having an exhaust port 11 a for exhausting the introduced sample gas. The hollow member 11 is accommodated in the hollow member 11 and collects the sample gas, and the hollow member 11 is brought into a high temperature state to desorb the sample gas collected in the collector 12. Heating means 13 for heating, and the sample gas introduced into the hollow member 11 is collected in the collecting agent 12 and collected in the collecting agent 12 when the sample gas is in a low temperature state. and desorption at high temperature, the sample gas collecting apparatus 1 for introducing the desorbed gas sample to the analysis unit 5, the inlet port 11b and the exhaust when desorbing the sample gas from said capturing agent 12 a busy tool hand stepped mouth 11a, the introduction In a state in which 11b and the exhaust port 11a is blocked and vacuum the hollow member 11 to facilitate detachment from the scavenger 12 of the sample gas, after the decompression, the hollow member And pressure adjusting means 15 for extruding the desorbed sample gas from the introduction port 11b and introducing it into the analysis means 5 .

  According to a second aspect of the present invention, in the sample gas collecting device according to the first aspect, the pressure adjusting means 15 heats the hollow member 11 by the heating means 13 and then the inside of the hollow member 11. It is a means for depressurizing.

  The gas chromatograph according to claim 3, which has been made according to the present invention to solve the above problems, is the sample gas collector 1 according to claim 1 and the sample gas desorbed by the sample gas collector 1. And analyzing means 5 for analyzing the components.

As described above, according to the sample gas collecting device of the present invention described in claim 1, after collecting the sample gas in the collecting agent, the introduction port and the exhaust port are closed to reduce the pressure inside the hollow member. heating the sample gas is desorbed from the absorption agent, which by pressure within the hollow member and pushed out from the inlet, since it has to be introduced into the analyzing means, electrode gas sample from the collection agent A sample gas that can be desorbed in a short time and desorbed with a minimum amount of carrier gas can be delivered. Therefore, since the separability of the collected sample gas can be improved and a high concentration sample gas can be sent out in a short time, the running cost can be reduced.

  According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the hollow member and the collecting agent are heated and then the inside of the hollow member is decompressed. Since the sample gas can be desorbed in a shorter time, the separability of the collected sample gas can be further improved.

  As described above, according to the gas chromatograph apparatus of the present invention described in claim 3, the sample gas collecting apparatus that improves the separability of the collected sample gas and delivers a high concentration sample gas in a short time. Therefore, the sample gas collection device can send a high concentration of sample gas to the analysis means in a short time, and the analysis means can obtain a sudden detection peak. Analysis. Therefore, measurement with high accuracy and good reproducibility is possible, and the running cost required for analyzing the sample gas can be reduced.

Hereinafter, an embodiment of a gas chromatograph (GC) device with a sample gas collecting device and the sample gas collecting apparatus according to the present invention will be described with reference to the drawings of FIGS. 1-6.

In FIGS. 2-6, a gas chromatograph (hereinafter, GC device) 3 includes a sample gas collecting apparatus 1, and the activated carbon filter 4, and analysis means 5, a buffer 6, a flow means 7, the control unit 8 , And are sequentially incorporated in the component detection path R.

  The component detection path R includes a flow path R1 that connects the sample gas collection device 1 and the activated carbon filter 4, a flow path R2 that connects the sample gas collection device 1 and the analysis means 5, an analysis means 5 and a buffer 6. And a bypass path R4 for connecting the activated carbon filter 4 and the analysis means 5 to each other.

  As shown in FIG. 1, the sample gas collecting apparatus 1 includes a cylinder 11 as a hollow member, a collecting agent 12, a cooling and heating means 13 as a heating means, an electromagnetic valve 14 as a closing means, and a pressure. It has a piston 15 as an adjusting means, a gasket 16, and a sealant 17, and they are integrally formed.

The cylinder 11 accommodates the piston 15 and is formed of a heat conductive member in a substantially cylindrical shape in which the piston 15 reciprocates. The cylinder 11 has an introduction port 11b for introducing the sample gas and an exhaust port 11a for exhausting the introduced sample gas. The flow path R1 is connected to the exhaust port 11a and the flow path R2 is connected to the introduction port 11b, so that the cylinder 11 is incorporated as a part of the component detection path R.

The collection agent 12 is formed in a cylindrical shape corresponding to the cross-sectional shape of the cylinder 11 by a member that adsorbs the sample gas, for example, a material that adsorbs and collects gas molecules such as TENAX, activated carbon, and zeolite. . And the collection agent 12 is accommodated in the cylinder 11 so that it may be located in the exhaust-port 11a vicinity. The collector 12 adsorbs and collects the sample gas flowing in the hollow member 11 in a low temperature state. Then, the collected sample gas is desorbed by being heated to a high temperature state that is equal to or higher than the desorption temperature.

  The cooling and heating means 13 is provided along the outer peripheral surface of the cylinder 11, and a known cooling device such as a cooler and a heating device such as a heater are used. The cooling device and the heating device are switched between cooling and heating by external control. The cooling and heating means 13 promotes cooling or heating of the collection agent 12 described above by cooling or heating the cylinder 11.

The electromagnetic valve 14 is provided so as to connect the exhaust port 11a of the cylinder 11 and the flow path R1, and is configured to allow sample gas or the like to flow. The electromagnetic valve 14 has a hollow cylindrical housing 14a, a movable valve 14b accommodated in the housing 14a, and an electromagnet 14c that generates an electromagnetic force for moving the movable valve 14b.

The electromagnetic valve 14 moves the movable valve 14 b using the electric power of the electromagnet 14 c generated by the control of the control means 8. Specifically, the electromagnetic valve 14 has a structure that closes the exhaust port 11a of the cylinder 11 by opening the internal flow path of the housing 14a when the valve is open, and blocking the internal flow path when the valve is closed. ing. Therefore, when the sample gas is desorbed from the collection agent 12, the electromagnetic valve 14 is switched to the valve closed state, thereby closing the exhaust port 11a and sealing the inside of the cylinder 11.

The piston 15 reciprocates in the reciprocating direction X in the cylinder 11 described above by a drive mechanism (not shown) under the control of the control means 8. The piston 15 is normally positioned on the lower side of the cylinder 11 in the vicinity of the collecting agent 12 and the introduction port 11b, and is lifted upward from the lower side at the time of depressurization, thereby depressurizing the inside of the cylinder 11.

  The gasket 16 is provided between the cylinder 11 and the piston 15 to improve airtightness. As the gasket 16, silicon rubber, chloroprene rubber, fluorine rubber, nitrile rubber, tetrafluoroethylene resin, ethylene propylene rubber, or the like is used.

  The sealant 17 is positioned and held at a predetermined position in the cylinder 11 with the collection agent 12 sandwiched therebetween. The sealant 17 is made of various mesh members capable of passing (penetrating) a sample gas or the like, and is fixed to the cylinder 11 so as not to move even if the inside of the cylinder 11 is depressurized by the piston 15.

The sample gas collecting apparatus 1 configured as described above is cooled by introducing the sample gas into the cylinder 11 when the cylinder 11 is cooled by the cooling and heating means 13 and when the electromagnetic valve 14 is open. The sample gas is collected (adsorbed) by the collected collecting agent 12. Then, when the pressure inside the cylinder 11 is reduced, the exhaust port 11a of the cylinder 11 is closed by the electromagnetic valve 14.

  By heating the cylinder 11 by the cooling and heating means 13, the collecting agent 12 is heated in advance, and the piston 15 is moved above the cylinder 11. Thereby, when the inside of the cylinder 11 is depressurized, the sample gas collected by the collecting agent 12 is quickly desorbed, and the sample gas can be efficiently desorbed from the collecting agent 12.

When the sample gas is desorbed from the collection agent 12, the solenoid valve 14 is opened for a certain period, and then switched to the valve open state, and the piston 15 moved above the cylinder 11 is moved downward, that is, the collection agent. By moving toward 12, the sample gas desorbed in the cylinder 11 is pushed out from the inlet 11 b to the flow path R <b> 2. Therefore, the sample gas desorbed by heating with the minimum carrier gas can be sent to the analyzing means 5 in a very short time.

According to the sample gas collecting apparatus 1 of the present invention described above, after collecting the sample gas in the collecting agent 12, the exhaust port 11a is closed and the inside of the cylinder 11 is decompressed and heated to collect the sample gas. 12 and desorbed from the inlet 11b by pressurization in the cylinder 11, so that the sample gas can be desorbed from the collection agent 12 in a very short time and the minimum carrier The sample gas desorbed with gas can be sent out. Therefore, since the separability of the collected sample gas can be improved and a high concentration sample gas can be sent out in a short time, the running cost can be reduced.

  Further, since the inside of the cylinder 11 is depressurized after the cylinder 11 and the collecting agent 12 are heated, the sample gas can be desorbed from the collecting agent 12 in a shorter time. Gas separability can be further improved.

Next, as shown in FIGS. 2 to 5 , the activated carbon filter 4 of the above-described GC device 3 sucks the atmosphere from the intake port, removes impurities contained in the atmosphere by the activated carbon in the filter, and generates a carrier gas. To do.

  Although not shown, the analysis means 5 has a column and a gas sensor. As the column, a known separation column of a gas chromatograph or the like is used. The column is heated by the heater, and the sample gas introduced from the flow path R2 is separated and sent on the time axis (predetermined measurement period) according to the type (measurement target component).

  As the gas sensor, a contact combustion type gas sensor, an adsorption combustion type gas sensor or the like is used. For example, a sensor signal indicating a gas concentration is output to the control means 8 based on a resistance difference between the sensitive element part and the sensitive element part.

  The control means 8 includes a microprocessor unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (A Write / Read Memory as needed). The control means 8 is electrically connected to the sample gas collection device 1, the analysis means 5, the flow means 7, the three-way valves V1, V2, etc., and controls each of them. That is, the control means 8 stores the program for controlling the sample gas collection apparatus 1 in the ROM and executes it.

  The buffer 6 is an existing buffer for suppressing the flow turbulence by the flow means 7 and keeping the flow amount constant. By providing the buffer 6, the flow amount is stabilized, so that the detection accuracy can be improved. . Further, if the error due to the flow disturbance of the flow means 7 is within an allowable range, the buffer 6 may be omitted.

  The flow means 7 has a pump 7a and a flow direction switching valve 7b. The pump 7a discharges the gas sucked from the pump suction port 7a1 from the pump discharge port 7a2 to flow the sample gas or the like in the component detection path R. As the flow direction switching valve 7b, for example, a four-way electromagnetic valve is used, and the sample gas and the carrier gas are flowed so as to pass through the component detection path R.

  The flow direction of the pump 7a is fixed in a fixed direction, and the flow direction of the gas flowing in the component detection path R is changed by switching the direction connected to the component detection path R by a flow direction switching valve 7b described later. Can be switched.

  The three-way valve V1 is provided in the flow path R1. The three-way valve V1 includes three ports a, b, and c. The activated carbon filter 4 is provided in the port a, the intake / exhaust port is provided in the port b, and the electromagnetic valve 14 of the sample gas collecting device 1 is provided in the port c. It is connected. The three-way valve V1 connects the sample gas collecting device 1 and the intake / exhaust port according to the introduction of the sample gas (bc connection), and the activated carbon filter 4 and the sample gas collecting according to the introduction of the carrier gas. The device 1 is connected (ac connection).

  The three-way valve V2 is provided in the flow path R2. The three-way valve V2 is provided at the end of the flow path R4 that bypasses the sample gas collection device 1 and the analysis means 5. In addition, three ports a, b, c are provided, the port a has an end of the sample gas collecting device 1 located on the analysis means 5 side, the port b has a flow path R4, the port c has an analysis means 5, Are connected to each other. The three-way valve V2 selects and switches either the sample gas collection device 1 or the bypass route R4 as a route for flowing the carrier gas. That is, the sample gas collection device 1 and the analysis means 5 (ac connection) or the flow path R4 which is a bypass path and the analysis means 5 (bc connection) are selectively connected.

Next, the control unit 8 of the gas chromatograph apparatus 1 (i.e., CPU, etc.) An example of a process according to the present invention is performed will be described with reference to the flowchart shown in schematic operation diagram and 6 of FIGS. 2-5 .

  When the gas chromatograph apparatus 1 is activated by turning on the power, the flow direction switching valve 7b switches the flow direction by the pump 7a to the direction from the sample gas collection device 1 toward the analysis means 5 (hereinafter, detection direction A), After performing a predetermined initialization operation such as connecting the analyzing means 5 and the sample gas collecting device 1 by the three-way valve V2, and connecting the activated carbon filter 4 and the sample gas collecting device 1 by the three-way valve V1, Proceed to step S110.

  In step S110, the sample gas collection device 1 and the column of the analysis means 5 are heated to a high temperature to desorb the impure components adsorbed on each, and then flow by the pump 7a is started. As a result, the carrier gas flows so as to pass through the column of the sample gas collection device 1 and the analysis means 5, and the desorbed impure components are discharged out of the GC device 3 by the carrier gas (see FIG. 2 above). Cleaning operation). And after discharge | emission of an impure component is completed, in order to raise collection efficiency in step S120, the sample gas collection apparatus 1 is heated.

  In step S130, the flow direction by the pump 7a is switched by the flow direction switching valve 7b to the direction from the analysis means 5 toward the sample gas collection device 1 (hereinafter referred to as collection direction B), and the sample gas is collected by the three-way valve V1. The apparatus 1 and the intake / exhaust port are connected, and the column of the analysis means 5 is continuously heated. At this time, the sample gas collection device 1 minimizes the capacity in the cylinder 11 by pushing the piston 15 down. Then, by introducing the sample gas, the sample gas passes through the analysis means 5 and is introduced into the sample gas collecting device 1. After the sample gas component is collected by the sample gas collecting device 1, the sample gas is collected. The sample gas that has passed through the gas collection device 1 is discharged from the intake / exhaust port (see FIG. 3, sampling operation). Then, in the sampling operation, the column is continuously heated to prevent the sample gas component from being adsorbed to the separation column, and the sample gas collecting device 1 is cooled to The sample gas is easily adsorbed (collected). And after collection of sample gas is completed, it progresses to Step S140.

  In step S140, the flow direction switching valve 7b switches the flow direction by the pump 7a to the detection direction A to flow the carrier gas, the three-way valve V2 connects the analysis means 5 and the flow path R4, and the flow by the pump 7a. To start. As a result, the carrier gas flows so as to pass through the column of the analysis means 5, and the desorbed impure components are discharged out of the GC apparatus 3 by the carrier gas. Then, after discharging the impure components is completed, the process proceeds to step S150.

In step S150, the cooling and heating means 13 of the sample gas collecting apparatus 1 is switched to the heating state. In step S160, the solenoid valve 14 is closed, the port of the three-way valve V2 is set to bc, and the piston 15 is pulled up to decompress the inside of the cylinder 11 (see FIG. 4 above, desorption operation). The electromagnetic valve 14 is opened for a certain period, and the process proceeds to step S170.

In step S170, the analyzing means 5 and the sample gas collecting device 1 are connected by the three-way valve V2, and the column is heated to a high temperature suitable for sample gas component separation. Then, by depressing the piston 15, the high-concentration sample gas desorbed and staying in the sample gas collecting device 1 is discharged (introduced) to the analysis means 5 (that is, the column), and the process proceeds to step S180. Advance (see FIG. 5 above, analysis 1 operation) .

In step S180, the analysis means 5 and the flow path R4 are connected by the three-way valve V2 to circulate the carrier gas, and the sample gas components contained in the sample gas introduced into the column are separated. The sample gas components are conveyed to the gas sensor of the analysis means 5 with a time difference, and each component is detected ( see FIG. 4, analysis 2 operation ). After all the detection target components are conveyed, the process returns to step S110 and a series of processes is repeated.

  According to the gas chromatograph device 3 of the present invention described above, the sample gas collecting device 1 that improves the separability of the collected sample gas and delivers a high concentration sample gas in a short time is provided. The sample gas collection device 1 can send a high concentration of sample gas to the analysis means 5 in a short time, and the analysis means 5 can obtain a sudden detection peak, so that the gas components can be analyzed efficiently. can do. Therefore, measurement with high accuracy and good reproducibility is possible, and the running cost required for analyzing the sample gas can be reduced.

  The analysis outline of the gas chromatograph apparatus 3 in the present embodiment described above is an example. For example, by switching the three-way valve V1 and the flow direction switching valve 7b and closing the electromagnetic valve 14, the analysis channel shown in FIG. The atmosphere is introduced from the intake port, moisture and gas components are removed by the activated carbon filter 4 to create a purge gas, and the three-way valve V1, the analysis means 5, the buffer 6 and the flow means 7 are purged, and at the same time the sample The sample gas collected by heating the gas collection device 1 is desorbed, or in the configuration shown in FIG. 2, the sample gas collection device 1 and the intake / exhaust port are connected by the three-way valve V1, and the heater is heated to a high temperature. The three-way valve V1, the analysis means 5, the buffer 6 and the flow means 7 are purged using the air introduced from the intake / exhaust port as the purge gas, and at the same time, the sample gas collecting device 1 is heated. The sample gas collecting Te can be of various different embodiments such as to desorb.

  The above-described embodiments are merely representative examples of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

It is a cross-sectional schematic diagram which shows schematic structure of the sample gas collection apparatus of this invention. It is a block diagram which shows schematic structure which concerns on the cleaning operation | movement of the gas chromatograph apparatus of this invention. It is a block diagram which shows schematic structure which concerns on sampling operation | movement of the gas chromatograph apparatus of this invention. It is a block diagram which shows schematic structure which concerns on the desorption | desorption and analysis operation | movement 2 of the gas chromatograph apparatus of this invention. It is a block diagram which shows schematic structure which concerns on the analysis operation 1 of the gas chromatograph apparatus of this invention. It is a flowchart which shows an example of the process outline | summary of the gas chromatograph apparatus of this invention. It is a block diagram of the conventional gas chromatograph apparatus.

Explanation of symbols

1 Sample gas collector 3 Gas chromatograph 11 Hollow member (cylinder)
12 Collection agent 13 Heating means (cooling heating means)
14 Blocking means (solenoid valve)
15 Pressure adjusting means (piston)

Claims (3)

A hollow member having an introduction port for introducing a sample gas, an exhaust port for exhausting the introduced sample gas, a collecting agent accommodated in the hollow member for collecting the sample gas, and the collecting agent Heating means for heating the hollow member so as to be in a high temperature state for desorbing the collected sample gas, and the sample gas introduced into the hollow member is used as the collecting agent in a low temperature state. the collected and sample gas was collected in the collection agent desorption when the high temperature state, the sample gas collecting device to be introduced into the analyzing means desorbed sample gas,
A busy tool hand stage the inlet and outlet when desorbing the sample gas from the capturing agent,
In a state where the introduction port and the exhaust port are blocked, the inside of the hollow member is depressurized to promote desorption of the sample gas from the collecting agent, and after the depressurization, the inside of the hollow member Pressure adjusting means for pressing the desorbed sample gas through the inlet and introducing it into the analyzing means ;
A sample gas collecting device comprising:   2. The sample gas collecting device according to claim 1, wherein the pressure adjusting means is means for reducing the pressure inside the hollow member after the hollow member is heated by the heating means.   A gas chromatograph device comprising: the sample gas collection device according to claim 1; and an analysis unit that analyzes a component of the sample gas desorbed by the sample gas collection device.

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