JP2009236590A - Gas chromatograph device and gas component desorption method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas chromatograph device and a gas component desorption method, capable of efficiently desorbing a detection object component collected by a collection member, and removing restrictions on a gas channel constitution. <P>SOLUTION: In this gas chromatograph device 1 equipped with a gas channel 5 having the collection member 11a for collecting a sample gas component and desorbing the collected sample gas component, and a gas flow means 20 for making purge gas flow to pass the collection member 11a, the gas channel 5 has a pressure loss generation part 30 arranged in series on the furthermore upstream side than the collection member 11a relative to the flow direction of the purge gas, for generating a pressure loss during flow of the purge gas, and the gas flow means 20 is a means arranged in series on the furthermore downstream side than the collection member 11a relative to the flow direction of the purge gas, for drawing the purge gas into the gas channel 5 through the pressure loss generation part 30 and making it flow to generate a negative pressure in a section from the pressure loss generation part 30 in the gas channel 5 to the gas flow means 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas chromatograph apparatus for detecting a substance (component) contained in a sample gas and a gas component desorption method used in the gas chromatograph apparatus.

  A gas chromatograph apparatus (hereinafter referred to as a GC apparatus) is an apparatus used for detecting a component to be detected (ie, a sample gas component) such as a volatile organic compound contained in a sample gas such as a house atmosphere. In order to enable detection of trace components contained in gas, in addition to a detection device equipped with a separation column and a detection sensor, a configuration equipped with a collection device for collecting and concentrating the components to be detected Is generally used.

  As shown in FIG. 11, 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 detection target component, and a component of a 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 detection target from the sample gas A collecting tube (collecting member) 102 provided with a collecting agent for collecting components, an orifice 113 connected to a carrier gas introduction side end of the collecting tube 102, and the collecting tube 102 as a sample introduction port 101 and the suction pump 104 or a valve 105 that is selectively connected between the carrier gas source 108 and the analyzer 110.

In general, the desorption of the sample gas component from the collection agent is mainly affected by temperature and pressure. The higher the temperature and the lower the pressure, the easier the sample gas component is desorbed from the collection agent. It is known to be. When desorbing the detection target component collected in the collection tube 102 in the GC device 100, the valve 105 is switched to change the carrier gas source 108, the valve 105, the piping 114b, the orifice 113, and the collection tube. Each of them is connected in series in the order of 102, and a carrier gas (that is, a purge gas) flows from the carrier gas source 108 toward the collection tube 102. Then, since the purge gas passes through the orifice 113 immediately before flowing into the collection tube 102, the purge gas flows into the collection tube 102 in a state where the flow rate is reduced and the flow velocity is increased, and therefore, the Bernoulli effect due to the increased flow velocity. As a result, the pressure in the collection tube 102 is reduced (depressurized), the desorption of the detection target component collected in the collection tube 102 is promoted, and the desorption efficiency is improved.
JP 2006-337158 A

  However, in Patent Document 1, since the collection pipe 102 is connected to the downstream side of the carrier gas source 108, the purge gas is pushed into the collection pipe 102 from the upstream side via the orifice 113. Since the pressure reduction due to the Bernoulli effect works only in the vicinity of the orifice 113, only a part of the collection tube 102 has a desorption promoting effect due to the pressure reduction. Further, the separation column of the analyzer 110 is generally a thin tube. As a result, pressure loss occurs in the separation column, the pressure in the collection tube rises, and the pressure reduction due to the Bernoulli effect is offset, so that the sample gas component is not sufficiently desorbed from the collection tube. There was a problem. Further, since the Bernoulli effect occurs only in the vicinity of the orifice 113, in order to obtain the effect in the collection tube 102, it is necessary to connect the collection tube 102 and the orifice 113, so that the gas flow path of the GC device 100 is provided. However, there is a problem that the degree of freedom in device design is impaired.

  Therefore, an object of the present invention is to enable a gas chromatograph apparatus and a gas capable of more efficiently desorbing a detection target component collected by a collecting member and eliminating a restriction on a gas flow path configuration. It is to provide a component desorption method.

  In order to solve the above problems, the gas chromatograph according to claim 1 according to the present invention, as shown in the basic configuration diagram of FIG. A gas flow path 5 having a collecting member 11a from which the collected sample gas component is desorbed according to the flow and a gas flow means 20 for flowing the purge gas so as to pass through the collecting member 11a is provided. In the gas chromatograph apparatus 1, the gas flow path 5 is arranged in series upstream of the collecting member 11a with respect to the flow direction of the purge gas, and the pressure loss generating section 30 that generates pressure loss when the purge gas flows is provided. The gas flow means 20 is arranged in series downstream of the collection member 11a with respect to the flow direction of the purge gas, and the pressure of the gas flow path 5 It is a means for drawing the purge gas into the gas flow path 5 through the pressure loss generator 30 so that a negative pressure is generated in the section from the generator 30 to the gas flow means 20. It is.

  The gas chromatograph apparatus according to claim 2 is the gas chromatograph apparatus according to claim 1, wherein, as shown in the basic configuration diagram of FIG. 1, the gas flow path 5 includes the collecting member 11a and the pressure loss generating portion. And a filter 22 for generating a carrier gas for collecting the impurity contained in the atmosphere and conveying the sample gas component.

  As shown in the basic configuration diagram of FIG. 1, the gas component desorption method according to claim 3 collects a sample gas component according to the flow of the sample gas and collects the sample gas according to the flow of the purge gas. A collecting member 11a from which a gas component is desorbed, and a gas that is arranged in series downstream of the collecting member 11a with respect to the flow direction of the purge gas and flows the purge gas so as to pass through the collecting member 11a A gas flow path 5 having a flow means 20 and a pressure loss generating portion 30 that is arranged in series upstream of the collecting member 11a with respect to the flow direction of the purge gas and generates a pressure loss when the purge gas flows is provided. In the gas component desorption method used in the gas chromatograph apparatus 1, a negative pressure is generated so that a negative pressure is generated in the section from the pressure loss generating part 30 to the gas flow means 20 of the gas flow path 5. A method characterized by having a desorption step of the purge gas through the pressure loss generating unit 30 to flow by drawing in the gas flow path 5.

  According to the gas chromatograph of the present invention as set forth in claim 1, the pressure loss generating part 30 and the gas flow means 20 cause a negative pressure to be generated in the section from the pressure loss generation part 30 to the gas flow means 20 of the gas flow path 5. Since the purge gas is drawn into the gas flow path 5 through the pressure loss generating portion 30 and flows therethrough, a negative pressure is generated over the entire interior of the collection member 11a when the purge gas flows, and the collection member 11a collects the purge gas. The desorbed sample gas component can be more efficiently performed. Further, since the purge gas is caused to flow by the gas flow means 20, a stronger negative pressure can be generated, and the sample gas component can be desorbed more efficiently. Further, the pressure loss generating unit 30 only needs to be arranged upstream of the collecting member 11a, and does not need to be connected to the collecting member 11a. Design becomes possible.

  According to the gas chromatograph apparatus of the present invention as set forth in claim 2, since the filter 22 is arranged in series between the collection member 11a and the pressure loss generating part 30, the gas flow path 5 by the purge gas flow During the cleaning, a negative pressure is generated in the filter 22 and the impurities collected in the filter 22 are desorbed, so that the filter 22 can be cleaned. Therefore, it becomes possible to suppress the progress of the deterioration of the filter 22, and the service life can be extended.

  According to the gas component desorption method of the present invention as set forth in claim 3, the purge gas is passed through the pressure loss generation unit 30 so that a negative pressure is generated in the section from the pressure loss generation unit 30 of the gas flow path 5 to the gas flow means 20. Thus, the sample gas component collected in the collecting member 11a can be generated by being drawn into the gas flow path 5 and generating a negative pressure over the entire inside of the collecting member 11a by the flow of the purge gas. Can be more efficiently desorbed. In addition, since the purge gas is caused to flow into the gas flow path 5, a stronger negative pressure can be generated, and the sample gas component can be desorbed more efficiently.

  Hereinafter, an embodiment of a gas chromatograph apparatus according to the present invention will be described with reference to the drawings of FIGS.

  As shown in FIG. 2, the gas chromatograph device (hereinafter referred to as GC device) 1 includes a component detection path 10 in which a collection device 11 and a detection device 12 are connected in series, and a detection device 12 side of the component detection path 10. A buffer 26, a gas flow unit 20, a sample introduction unit 23, which are sequentially connected in series, an activated carbon filter 22, an orifice 30A, and an air inlet 21, which are sequentially connected in series to the collection device 11 side of the component detection path 10; A bypass path 31 disposed in parallel to the collection device 11, an orifice 35 connected in series on the bypass path 31, and a bypass path 31 positioned between the collection device 11 and the detection device 12. A bypass valve 32 disposed at the end, a discharge valve 42 disposed between the collection device 11 and the activated carbon filter 22, and an orifice connected in series to the discharge valve 42 in series. Scan 30B and discharge ports 41, a control unit 51 for controlling the operation of the GC apparatus 1, in being configured.

  The collection device 11 is a device for collecting and concentrating sample gas components so as to enable detection of trace components contained in the sample gas, and includes a collection tube 11a, a collection tube heating / cooling device 11b, and the like. It has.

  The collection tube 11a corresponds to the collection member of the claims. For example, a collection tube corresponding to a detection target component such as a heat resistant resin or carbon black is disposed inside a glass tube having an inner diameter of about 5 mm and a length of about 20 to 30 cm. Filled with collector. Then, by passing the sample gas through the low temperature collection tube 11a, the sample gas component is adsorbed (collected) to the collection agent, and then the sample gas component collected by being heated to a high temperature is collected. Desorbed from the collecting agent to produce a highly concentrated sample gas. Further, the collection tube 11a is pressurized to promote the adsorption of the sample gas component, and the pressure inside the collection tube 11a is promoted to desorb the sample gas component. The gas staying in the collection tube 11a is pushed out of the collection tube 11a by the carrier gas or the atmosphere (that is, purge gas).

  The collection tube heating / cooling device 11b cools the collection tube 11a according to the collection of the sample gas component and heats the collection tube 11a according to the desorption of the sample gas component. This is an existing apparatus that includes a heater such as a heat wire and a Peltier element as a cooling means. The collection tube heating / cooling device 11 b is connected to a control device 51 described later, and is controlled in conjunction with other members constituting the GC device 1.

  The detection device 12 is a device that detects a component by introducing a high-concentration sample gas generated by the collection device 11, and includes a separation column 12a, a column heating / cooling device 12b, and a detection sensor 12c.

  The separation column 12a is for separating components contained in the sample gas, and is a packed column in which a tube having a diameter of 2 to 6 mm and a length of several meters is filled with a granular stationary phase, an inner diameter of about 0.5 mm or less, Existing columns such as capillary columns with a liquid stationary phase held directly on the wall of a thin tube of several tens of meters, or microcolumns in which fine column grooves are formed in a glass plate by etching are used. .

  The column heating / cooling device 12b adjusts the temperature of the separation column 12a according to the introduction of the sample gas into the separation column 12a and the separation of the sample gas components, and includes a heater such as a heating wire as a heating means, and a cooling means It is an existing device equipped with a Peltier element. The column heating / cooling device 12b is connected to a control device 51, which will be described later, and is controlled in conjunction with other members constituting the GC device 1.

  The detection sensor 12c is for detecting a sample gas component that has been transported by a carrier gas after being separated in the separation column 12a. For example, a flame ionization detector, a thermal conductivity detector, or the like is used. An existing detector is used, and the detection sensor 12c is connected to a control device 51, which will be described later, and is controlled in conjunction with other members constituting the GC device 1. Since the configuration and operation of the detection sensor 12c are not related to the essence of the present invention, the details are omitted.

  The gas flow unit 20 corresponds to the gas flow means of the claims, and includes a pump 24 that flows the sample gas and the carrier gas, and a flow direction switching valve 25 that switches the flow direction of each gas that the pump 24 flows. ing.

  The pump 24 discharges and flows the gas sucked from the pump suction port 24a through the pump discharge port 24b, and flows the sample gas and the carrier gas so as to pass through the component detection path 10, respectively. The gas flow rate and flow rate can be finely controlled according to the situation so that the gas flows properly. The flow direction of the pump 24 is fixed in a fixed direction, and the direction connected to the component detection path 10 is switched by a flow direction switching valve 25 described later, that is, the flow direction of the gas flowing in the component detection path 10 is changed. Can be switched. The pump 24 is connected to a control device 51 to be described later, and is controlled in conjunction with other members constituting the GC device 1.

  For example, a four-way solenoid valve is used as the flow direction switching valve 25, and a buffer 26, a sample introduction unit 23, a pump suction port 24a, and a pump discharge port 24b are connected to the four connection ports. When the sample gas is introduced, the buffer 26 and the pump discharge port 24b, and the sample introduction unit 23 and the pump suction port 24a are connected to each other, so that the sample gas introduced from the sample introduction unit 23 is transferred to the component detection path 10. When the connection is switched so that the inside flows from the detection device 12 toward the collection device 11 and the carrier gas is introduced, the buffer 26 and the pump suction port 24a, and the sample introduction unit 23 and the pump discharge port 24b are connected. Then, the connection is switched so that the carrier gas provided from the activated carbon filter 22 described later flows in the component detection path 10 from the collection device 11 toward the detection device 12. Further, the flow direction switching valve 25 is connected to a control device 51 described later, and is controlled in conjunction with other members constituting the GC device 1.

  The buffer 26 is an existing one for suppressing the disturbance of the flow caused by the pump 24 and keeping the flow amount constant, and the flow amount is stabilized by arranging the buffer 26 on the path, so that the detection accuracy is improved. Can do. Further, the buffer 26 may be omitted if the error due to the disturbance of the flow of the pump 24 is within an allowable range.

  The sample introduction unit 23 is disposed at an end of the configuration of the GC device 1 and is an introduction unit for introducing a sample gas into the GC device 1 when collecting a sample gas component. When the sample gas component is detected, it also functions as a discharge unit that discharges the carrier gas carrying the sample gas component out of the GC apparatus 1.

  The activated carbon filter 22 corresponds to the filter of the claims, and is disposed at the end of the GC apparatus 1 located on the opposite side of the sample introduction unit 23, and the component detection path is constituted by the pump 24 and the flow direction switching valve 25. 10 is sucked in the direction from the collection device 11 to the detection device 12, the air is sucked from the air suction port 21 connected to the activated carbon filter 22, and the activated carbon removes impurities contained in the air and removes the carrier gas. Is to be generated. Further, when the activated carbon filter 22 is passed through the atmosphere with the inside reduced pressure, the impure component collected by the activated carbon is desorbed and the activated carbon is cleaned.

  The bypass path 31 is a gas flow path for allowing the sample gas and the carrier gas to flow around the collection device 11, and one end of the bypass route 31 is interposed between the collection device 11 and the detection device 12 via the bypass valve 32. The other end is connected between the collection device 11 and the activated carbon filter 22.

  The bypass valve 32 is, for example, an existing three-way electromagnetic valve, and is provided at the end of the bypass path 31 positioned between the collection device 11 and the detection device 12. In addition, three ports a, b and c are provided, the port a includes the end of the collection device 11 located on the detection device 12 side, the port b includes the bypass path 31, and the port c includes the detection device 12 respectively. It is connected. The bypass valve 32 selects and switches either the collection device 11 or the bypass route 31 as a path for flowing the carrier gas, that is, the collection apparatus 11 and the detection apparatus 12 (ac connection). Alternatively, the bypass path 31 and the detection device 12 (bc connection) are selectively connected. Further, the bypass valve 32 is connected to a control device 51 described later, and is controlled in conjunction with other members constituting the GC device 1. The bypass valve 32 is provided at one end of the bypass path 31, but is not limited thereto, and selectively connects either the collection device 11 or the bypass path 31 and the detection device 12. If so, it may be provided at the other end or both ends of the bypass path 31.

  For example, an existing three-way solenoid valve is used as the discharge valve 42 and includes three ports d, e, and f. The activated carbon filter 22 is provided in the port d and the orifice 30B is provided in the port e. The discharge port 41 is connected to the port f at the end of the collection device 11 located on the side opposite to the detection device 12 side. The exhaust valve 42 connects the collection device 11 and the exhaust port 41 according to the introduction of the sample gas (ef connection), and the end portion and the activated carbon filter 22 according to the introduction of the carrier gas. Are connected (df connection). Further, the discharge valve 42 is connected to a control device 51 which will be described later, and is controlled in conjunction with other members constituting the GC device 1.

  The discharge port 41 is connected to the discharge valve 42 via the orifice 30B, is connected to the collection device 11 in accordance with the introduction of the sample gas, and the sample gas that has passed through the component detection path 10 is discharged to the outside of the GC device 1. To be discharged. Further, when the sample gas component desorbed in the collection device 11 is introduced into the detection device 12 (that is, during the driving operation), the atmosphere is sucked as a purge gas from the discharge port 41.

  The orifice 30 </ b> A corresponds to the pressure loss generating portion of the claims, and is a pipe line having a narrowed inner diameter so that a pressure loss is generated when the gas passes, and is provided between the air inlet 21 and the activated carbon filter 22. They are arranged in series.

  The orifice 30B corresponds to the pressure loss generating portion of the claims, has the same shape and the generated pressure loss as the orifice 30A, and is disposed in series between the discharge port 41 and the discharge valve 42.

  The orifice 35 is formed so that the pressure loss generated from the orifices 30 </ b> A and 30 </ b> B is small, and is arranged in series on the bypass path 31.

  The control device 51 includes a collection tube heating / cooling device 11b (A), a column heating / cooling device 12b (A), a detection sensor 12c (C), a pump 24 (D), a flow direction switching valve 25 (O). ), A bypass valve 32 (f), and a discharge valve 42 (g), and a microcomputer (MPU) (not shown) that controls them in conjunction with each other is provided. As is well known, the MPU is a central processing unit (CPU) that performs various processes and controls according to a predetermined program, a ROM that is a read-only memory storing programs for the CPU, and various data. An I / O unit that includes a RAM that is a readable / writable memory having an area necessary for CPU processing operations and a serial interface for transmitting / receiving control information to / from the above-described control target portion, etc. It consists of

  The CPU of the control device 51, based on a program stored in the ROM, collects the collection tube heating / cooling means for heating / cooling the collection tube 11a so that the temperature of the collection tube 11a becomes an appropriate temperature, and the separation column 12a. Column heating / cooling means for heating / cooling the separation column 12a so that the temperature becomes appropriate temperature, component detection means for detecting the sample gas component contained in the sample gas, sample gas flowing in the component detection path 10, and carrier gas A flow rate control means for controlling the flow rate and flow velocity of the gas, and in accordance with the introduction of the sample gas, the flow direction by the pump 24 is switched so that the sample gas flows from the detection device 12 toward the collection device 11, and the carrier gas is introduced In accordance with the flow direction switching means for switching the flow direction by the pump 24 so that the carrier gas flows from the collection device 11 toward the detection device 12 Bypass selection means for selecting and switching either the collection device 11 or the bypass route 31 as a route through which the carrier gas flows, and the collection device 11 and the discharge port 41 are connected in accordance with the introduction of the sample gas Then, according to the introduction of the carrier gas, it operates as an outlet selection means for connecting the collection device 11 side and the activated carbon filter 22.

  Next, an example of processing according to the present invention executed by the control device 51 (i.e., CPU) of the gas chromatograph apparatus 1 will be described with reference to the flowchart shown in FIG. 3 and the schematic operations corresponding to the steps shown in FIGS. This will be described with reference to the drawings.

  When the CPU of the control device 51 is activated by turning on the power of the GC device 1, the flow direction switching valve 25 causes the flow direction of the pump 24 to flow in the direction from the collection device 11 to the detection device 12 (hereinafter, detection direction). Switching, the bypass valve 32 connects the detection device 12 and the collection device 11 (ac connection), and the exhaust valve 42 connects the activated carbon filter 22 and the collection device 11 (df connection). After performing a predetermined initialization operation such as, the process proceeds to step S110.

  In step S110, the collection tube 11a and the separation column 12a are heated to a high temperature by the collection tube heating / cooling device 11b and the column heating / cooling device 12b to extract impure components, and then the carrier gas (that is, purge gas) by the pump 24 is used. Start flowing. Thereby, in addition to the high temperature by heating, the impure component can be more efficiently extracted from the activated carbon filter 22, the collection tube 11a, and the separation column 12a by the negative pressure generated in the section from the orifice 30A to the pump 24. . Then, the impure component is discharged out of the GC apparatus 1 by the purge gas (the operation of cleaning 1 in FIG. 4). After discharging the impure components, the process proceeds to step S120.

  In step S120, the flow direction by the pump 24 is switched by the flow direction switching valve 25 to the direction from the detection device 12 toward the collection device 11 (hereinafter, the collection direction), and the detection device 12 and the bypass path 31 by the bypass valve 32. And the column heating / cooling device 12b continuously heats the separation column 12a, the collection tube heating / cooling device 11b cools the collection tube 11a, and Sample gas is introduced from the sample introduction unit 23. As a result, the sample gas at the initial stage of introduction is discharged from the atmosphere suction port 21 via the bypass path 31 and the activated carbon filter 22, and the sample gas is introduced until the sample gas flow rate is not disturbed by the flow direction switching and is stabilized. , Avoiding a decrease in the collection efficiency due to the disturbance of the flow rate (the operation in FIG. 5 sampling 1). After the sample gas flow rate is stabilized, the process proceeds to step S130.

  In step S130, the discharge port 41 and the collection device 11 are connected via the orifice 30B (ef connection) by the discharge valve 42, and the detection device 12 and the collection device 11 are connected by the bypass valve 32 ( and the column heating / cooling device 12b continuously heats the separation column 12a, and the collecting tube heating / cooling device 11b continuously cools the collecting tube 11a. As a result, the sample gas passes through the detection device 12 and is introduced into the collection device 11. After the sample gas component is collected by the collection device 11, the sample gas that has passed through the collection device 11 is discharged. The gas is discharged from the outlet 41 (the operation in FIG. 6, sampling 2). By continuously heating the separation column 12a in the sampling 1 operation and the sampling 2 operation, the sample gas component is prevented from staying in the separation column 12a, and the sample tube 11a is cooled to thereby obtain the sample gas. The components are easily adsorbed (collected) by the collection tube 11a. Further, since the orifice 30B becomes a flow resistance when the sample gas is discharged from the discharge port 41, a positive pressure is generated in the section from the orifice 30B to the pump 24 due to the flow of the sample gas, and the pressure in the collection tube 11a. And the adsorption of the sample gas component to the collection tube 11a is promoted. In addition, the orifice 30A, the orifice 30B, and the orifice 35 reduce the difference in flow resistance of the sample gas before and after the switching of each valve, and the discharge valve at the transition of each operation, such as the transition from the sampling 1 operation to the sampling 2 operation. Disturbances in the flow of each gas caused by switching of 42 or the bypass valve 32 are minimized. Then, after the collection of the sample gas component is completed, the process proceeds to step S140.

  In step S140, the flow direction by the pump 24 is switched to the detection direction by the flow direction switching valve 25 to flow the carrier gas (that is, purge gas), and the detection device 12 and the bypass path 31 are connected by the bypass valve 32 (b) In addition, the column heating / cooling device 12b continuously heats the separation column 12a, and the collection tube heating / cooling device 11b heats the collection tube 11a to a high temperature. As a result, the purge gas passes from the activated carbon filter 22 through the detection device 12 (that is, the separation column 12a) via the bypass path and is discharged from the sample introduction unit 23. Therefore, the purge gas flows from the orifice 30A through the bypass path 31. A negative pressure is generated in the section up to the pump 24 via which the impure component is extracted more efficiently from the activated carbon filter 22 and the separation column 12a. Then, the impure component is pushed out by the purge gas together with the sample gas staying in the detection device 12 and discharged out of the GC device 1. In parallel with these operations, the collection tube 11a is heated in the collection device 11, whereby the sample gas component is desorbed. (The above is the cleaning 2 operation in FIG. 7). Then, after the discharge of the sample gas or the like staying in the detection device 12 is completed, the separation column 12a is cooled by the column heating / cooling device 12b. Then, after the separation column 12a is cooled to a temperature suitable for gas component separation and the sample gas component is sufficiently desorbed by the collection device 11, the process proceeds to step S150. Note that the temperature of the separation column 12a is maintained until the detection operation.

  In step S150, the detection device 12 and the collection device 11 are connected (ac connection) by the bypass valve 32. Thereby, the high-concentration sample gas desorbed and staying in the collection device 11 is pushed out by the atmosphere (that is, the purge gas) sucked from the discharge port 41, and the detection device 12 (that is, the separation column 12a). (In FIG. 8, driving operation). At this time, in addition to desorption by heating the collection tube 11a, a negative pressure is generated in the section from the orifice 30B to the pump 24 by the flow of the purge gas, and the desorption of the sample gas component from the collection tube 11a is promoted. The sample gas component is desorbed more efficiently. Then, after the high-concentration sample gas is introduced into the separation column 12a, the process proceeds to step S160.

  In step S160, the detection device 12 and the bypass path 31 are connected by the bypass valve 32 (bc connection), and the sample gas component contained in the sample gas introduced into the separation column 12a is separated by the carrier gas. Each sample gas component is separated in the column 12a and conveyed to the detection sensor 12c with a time difference, and each component is detected (the detection operation in FIG. 9 above). Further, the flow rate of the carrier gas during the detection operation is small enough that no negative pressure is generated in the gas flow path 5. Then, after all the detection target components have been conveyed, the processing of this flowchart is terminated. In addition, step S110, S150 mentioned above is corresponded to the isolation | separation process of a claim.

  Next, an example of the operation when performing the component detection of the sample gas in the gas chromatograph apparatus 1 described above will be described with reference to FIGS.

  In the component detection in the gas chromatograph apparatus 1, first, the collection tube 11a and the separation column 12a are heated to a high temperature, and a carrier gas is caused to flow in a section from the orifice 30A to the pump 24 to generate activated carbon. Impurity components are taken out from the filter 22, the collection tube 11a, and the separation column 12a, and the gas flow path 5 is cleaned (operation 1 cleaning in FIG. 4).

  After the cleaning of the gas flow path 5 is completed, the collection tube 11a is cooled. Then, the sample gas is introduced from the sample introduction unit 23, and the introduced sample gas is sequentially passed through the detection device 12, the collection device 11, and the orifice 30B, and is discharged from the discharge port 41, and from the orifice 30B to the pump 24. The sample gas component is collected by flowing so that a positive pressure is generated in this section. (FIG. 5 Sampling 1 operation, FIG. 6 Sampling 2 operation).

  After completing the collection of the sample gas component, the collection tube 11a is heated to desorb the collected sample gas component. At the same time, the carrier gas is caused to flow so as to generate a negative pressure in the section from the orifice 30A to the pump 24 via the bypass path 31, and the impure component is taken out from the activated carbon filter 22 and the separation column 12a. The sample gas is discharged from the sample introduction section 23 by the carrier gas together with the sample gas staying in the area. (FIG. 7 Cleaning 2 operation).

  After the cleaning of the activated carbon filter 22 and the detection device 12 is completed, the separation column 12a is cooled, and the sample gas component desorbed from the collection tube 11a is introduced into the detection device 12 (ie, the separation column 12a) (FIG. 8 driving operation). ). At the time of this introduction, the atmosphere is caused to flow in the gas flow path 5 so that a negative pressure is generated in the collection tube 11a.

  Then, the separation column 12a is heated at a predetermined temperature increase rate, and the carrier gas is introduced into the separation column 12a via the bypass path 31, thereby conveying the desorbed sample gas component to the detection sensor 12c. Then, the sample gas component is detected (detection operation in FIG. 9).

During the sampling 2 operation, since the collection tube 11a and the orifice 30B are downstream of the pump 24, the sample gas flows so as to be pushed into the collection tube 11a by the pump 24. A positive pressure is generated between them, and during the driving operation, since the collection pipe 11a and the orifice 30B are upstream of the pump 24, the sample gas staying in the collection pipe 11a is sucked out by the pump 24. Therefore, a negative pressure is generated between the orifice 30B and the pump 24. The pressure difference (pressure loss) ΔPf generated in the orifice 30A and the orifice 30B in the present embodiment is expressed by the following equation.
^{ΔPf = 4λ (ρμ 2/2} ) · (L / D) [Pa] ......... (1)
Here, D: orifice inner diameter, L: orifice tube length, ρ: fluid density, μ: viscosity coefficient, λ: tube friction coefficient. Here, as numerical values in the present embodiment, orifice inner diameter (D) 0.05 mm, orifice tube length (L) 1.0 mm, fluid density (ρ) 1.2 kg / m ³ , viscosity coefficient (μ) 0.000018 Pa・ As a result of substituting numerical values such as s (20 ° C.), pipe friction coefficient (λ) 5.65 × 10 ⁻² , etc. into equation (1), the value of ΔPf is about 19.58 kPa, that is, sampling The positive pressure and the negative pressure generated during the two operations and the driving operation are ΔPf, respectively, and a pressure difference larger than the configuration shown in Patent Document 1 can be generated throughout the collection tube 12a.

  As described above, according to this embodiment, the purge gas (that is, the carrier gas or the carrier gas or the pump gas 24) is generated by the orifice 30A, the orifice 30B, and the pump 24 so that a negative pressure is generated in the section from the orifice 30A or the orifice 30B to the pump 24 in the gas flow path 5. Atmosphere) is drawn into the gas flow path 5 and flows, so that a negative pressure is generated over the entire interior of the collection tube 11a when the purge gas flows, and the sample gas component collected in the collection tube 11a is removed. Separation can be performed more efficiently. Further, since the purge gas is caused to flow by the pump 24, a stronger negative pressure can be generated, and the sample gas component can be desorbed more efficiently. Therefore, a sample gas with a higher concentration can be generated, and the collection tube 11a can be cleaned more cleanly. In addition, the orifice 30A and the orifice 30B only need to be arranged upstream of the collection pipe 11a and do not need to be connected to the collection pipe 11a. Device design is possible.

  Further, since the activated carbon filter 22 is disposed in series between the collection tube 11a and the orifice 30A, a negative pressure is generated in the activated carbon filter 22 during cleaning of the gas flow path 5 by the purge gas flow, and the activated carbon. Since the impurities collected in the filter 22 are desorbed (that is, taken out), the activated carbon filter 22 can be cleaned, deterioration of the activated carbon filter 22 can be prevented, and its service life can be extended.

  Further, when the sample gas is introduced into the collection tube 11a, a positive pressure is generated in the section from the orifice 30B to the pump 24. Therefore, the adsorption of the sample gas component to the collection tube 11a is promoted, and the collection device 11 The concentration efficiency of the sample gas component due to can be improved.

  In the present embodiment, the orifice 30A is arranged in series between the activated carbon filter 22 and the air inlet 21. For example, as shown in FIG. 10, a carrier gas generator 221 that does not require cleaning is provided. In the configuration using the above, the orifice 30A1 is disposed between the carrier gas generation device 221 and the collection device 11, and the same orifice 30B1 as the orifice 30A1 is disposed on the bypass path 31. Similar to the above, the effect of promoting the collection and desorption in the collection tube 11a can be obtained.

  In the present embodiment, a method of performing separation of sample gas components (constant temperature method) while maintaining the temperature of the separation column 12a at a constant temperature during the detection operation is used. The method may be changed according to the sample gas to be detected, such as a method of separating the sample gas components while raising the temperature of the separation column 12a (temperature raising method).

  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 basic lineblock diagram of the gas chromatograph device of the present invention. It is a block diagram which shows one Embodiment of the gas chromatograph apparatus of this invention. It is a flowchart which shows an example of the process which concerns on this invention which CPU of the gas chromatograph apparatus in FIG. 2 performs. It is a figure which shows the state of the cleaning 1 operation | movement of the gas chromatograph apparatus in FIG. It is a figure which shows the state of the sampling 1 operation | movement of the gas chromatograph apparatus in FIG. It is a figure which shows the state of the sampling 2 operation | movement of the gas chromatograph apparatus in FIG. It is a figure which shows the state of cleaning 2 operation | movement of the gas chromatograph apparatus in FIG. It is a figure which shows the state of driving operation of the gas chromatograph apparatus in FIG. It is a figure which shows the state of the detection operation | movement of the gas chromatograph apparatus in FIG. It is a block diagram which shows other embodiment of the gas chromatograph apparatus of this invention. It is a block diagram of the conventional gas chromatograph apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas chromatograph apparatus 5 Gas flow path 11a Collection member (collection pipe)
20 Gas flow means (pump, flow direction switching valve)
22 Filter (activated carbon filter)
30 (30A, 30B) Pressure loss generating part (orifice)

Claims (3)

A sample gas component is collected according to the flow of the sample gas, and the purge gas is flowed so as to pass through the collection member from which the collected sample gas component is desorbed according to the flow of the purge gas. In a gas chromatograph apparatus provided with a gas flow path having gas flow means,
The gas flow path has a pressure loss generating portion that is arranged in series upstream of the collecting member with respect to the flow direction of the purge gas and generates a pressure loss when the purge gas flows;
The gas flow means is arranged in series downstream from the collection member with respect to the flow direction of the purge gas, and a negative pressure is generated in a section from the pressure loss generation portion of the gas flow path to the gas flow means. The gas chromatograph apparatus further comprises a means for drawing the purge gas into the gas flow path through the pressure loss generating portion and causing the purge gas to flow.   The gas flow path is disposed in series between the collection member and the pressure loss generation unit and collects impurities contained in the atmosphere to generate a carrier gas for transporting the sample gas component The gas chromatograph apparatus according to claim 1, further comprising: a filter. A collecting member that collects the sample gas component according to the flow of the sample gas and from which the collected sample gas component is desorbed according to the flow of the purge gas; and the collecting member with respect to the flow direction of the purge gas. A gas flow means arranged in series on the downstream side and flowing the purge gas so as to pass through the collection member; and the purge gas arranged in series upstream from the collection member with respect to the flow direction of the purge gas. A gas component desorption method used in a gas chromatograph apparatus provided with a gas flow path having a pressure loss generating section that generates a pressure loss when flowing,
A desorption step of drawing the purge gas into the gas flow path through the pressure loss generating section so that a negative pressure is generated in a section from the pressure loss generating section of the gas flow path to the gas flow means. Gas component desorption method.

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