JPH09178718A - Gas chromatograph - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gas chromatograph in which leakage of sample gas can be measured within a container by providing a gas piping for collecting the leaked gas in the container and introducing the collected gas to a sample introducing section. SOLUTION: A three-way switching section 15 is switched to bring about a state where a gas piping 13 is coupled with a sample gas system. A pump 14 is then operated to take in the gas from an analyzer section 100 and a sample conditioner section 200 before starting measurement using the gas thus taken in as a sample. If same components as those of the sample being fed through a sample gas inlet 201 are detected by measurement, a decision is made that the sample gas has leaked. When valves are fixed to the gas take-in parts 13a, 13b of gas piping 13 in order to make a switching between the analyzer section 100 and the sample conditioner section 200, a decision can be made in which region the sample gas has leaked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas chromatograph, and more particularly to a gas chromatograph for detecting leakage from a connecting portion such as a column constituting a gas chromatograph.

[0002]

2. Description of the Related Art A gas chromatograph is a useful device for analyzing liquids and gases composed of various organic compounds. In a gas chromatograph, a plurality of substances dissolved in a liquid to be analyzed can be separated and their amounts can be detected respectively, so that qualitative analysis and quantitative analysis can be performed simultaneously.
In a gas chromatograph, a solution to be analyzed is heated to form a gas, and the gas is passed through a column (fixed bed) for separating compounds having different structures by a carrier gas. The plurality of compounds dissolved in the gasified solution to be analyzed are separated by being carried by the carrier gas and passing through the column, and the respective amounts are separated by the detector arranged at the outlet of the column. To be measured.

FIG. 3 is a block diagram showing the structure of a conventional gas chromatograph. In FIG. 3, 1 is a pressure reducing valve for adjusting the pressure of the carrier gas, 2 a is a supply solenoid valve for adjusting the operation of the pressure reducing valve 1, and 2 b is a discharge solenoid valve for adjusting the operation of the pressure reducing valve 1. Reference numeral 3 is a pressure sensor that detects the pressure of the carrier gas on the secondary side of the pressure reducing valve 1. Reference numeral 4 denotes an analyzer valve, which includes a carrier gas introducing unit 44, a sample injecting unit 45, a measuring pipe 46 for measuring and holding a sample contained in the sample injecting unit 45 in a predetermined amount, and a substance to be analyzed. First column 47a and second column 47
b, a detector 48 for detecting the amount of each substance separated in the first and second columns 47a, 47b, and an exhaust pipe 49 for exhausting the carrier gas and the sample gas that have passed through the analyzer valve 4. There is.

Further, 8 is a valve driving electromagnetic valve for controlling a carrier gas for driving the analyzer valve, and 9 is A for A / D converting signals from the pressure sensor 3 and the detector 48.
/ D converter, 11 is a CPU, 12 is a solenoid valve 2a for supply,
This is an electromagnetic valve drive unit that outputs drive signals for the discharge electromagnetic valve 2b and the valve drive electromagnetic valve 8. Then, the pressure reducing valve 1 described above
And analyzer valve 4, A / D converter 9, CPU1
1, the portion excluding the solenoid valve drive unit 12 forms one module as the analyzer unit 100, and the inside is controlled to a substantially constant temperature.

The sample introduced to the sample injection unit 45 is
The sample conditioner unit 200 adjusts the flow rate to a predetermined value to remove foreign matters and the like. In the sample conditioner section 200, 201 is a sample gas introducing section, 202 is a standard gas introducing section, 203 is a bypass filter, 204 is a flow path switching section, 205 is a sample filter, 206 and 207 are needle valves, and 208 and 209 are flow rates. A thermometer 210 measures the temperature in the sample conditioner unit 200.

Most of the sample introduced from the sample gas introducing unit 201 is exhausted from the bypass vent through the needle valve 207 and the flow meter 209. A part of the foreign matter is pre-filtered by the bypass filter 203, and the sample filter 205
Is filtered by the needle valve 206, adjusted to a predetermined flow rate by the needle valve 206, and guided to the analyzer valve 4.
The needle valve 206 is adjusted while measuring the flow rate with the flow meter 208. As described above, the sample is always separated from the process so that the sample can be measured without delay from the process.

Even in the analyzer valve 4, the flow path is switched so that the sample always flows through the measuring pipe 46. The flow rate here is 50 ml / mi.
Sample conditioner part 2
At 00, the flow rate of the sample being collected is made to some extent. At the time of adjusting the gas chromatograph, the flow path switching unit 204 is switched so that the standard gas taken in from the standard gas introducing unit 202 is introduced into the analyzer valve 4 via the sample filter 205. The standard gas is not very dirty, so
Pre-filtering by the bypass filter 203 does not have to be performed and does not pass through here.

Further, the sample conditioner section 20
0 is adjusted to a predetermined temperature in order to prevent the sample taken in from liquefying, and this state is confirmed by looking at the thermometer 210. In the sample conditioner section 200, the place where the thermometer 210 inside is arranged can be seen from the outside. As a result of the above, the sample from which the foreign matter has been removed by adjusting the flow rate is guided to the sample injection part 45 of the analyzer valve 4.

In the analyzer valve 4, the connection of each flow path is switched by the pressure of the carrier gas whose on / off is controlled by the valve driving solenoid valve 8. First, when the valve drive solenoid valve 8 is off, the sample injection unit 45, the measuring pipe 46, and the discharge pipe 49 are connected to each other, while the carrier gas introduction unit 44, the first column 47a, and the discharge pipe 49 are connected to each other. The carrier gas introducing unit 44, the second column 47b, the detector 48, and the discharge pipe 49 are in communication with each other. Next, when the valve drive solenoid valve 8 is on, the carrier gas introducing portion 44 and the measuring pipe 46 are
The first column 47a, the second column 47b, the detector 48, and the discharge pipe 49 communicate with each other, while the sample injection unit 45 and the discharge pipe 49 communicate with each other.

The operation of this gas chromatograph is as follows. First, when the valve drive solenoid valve 8 is off, the sample gas introduced from the sample injection unit 45 into the analyzer valve is measured by the measuring pipe 46.
And is discharged from the discharge pipe 49. On the other hand, at this time, the carrier gas adjusted to a constant pressure by the pressure reducing valve 1 and the electromagnetic valves 2a and 2b is introduced into the analyzer valve 4 from the carrier gas introducing portion 44, passes through the first column 47a, and is discharged through the discharge pipe 49. From the second column 4
After passing through 7b, it passes through the detector 48 and is discharged from the discharge pipe 49.

When the valve drive solenoid valve 8 is turned on, the analyzer valve 4 switches its connection as described above. At this time, the sample gas introduced from the sample introducing unit 45 and passing through the measuring pipe 46 has the communication source of the measuring pipe 46 as the carrier gas introducing unit 44 and the communication destination as the first column 4
Since it becomes 7a, only the amount measured to a predetermined amount by the measuring pipe 46 is carried to the carrier gas and moved to the first column 47a. By passing through the first column 47a, the sample gas is separated to some extent for each contained component,
The carrier gas is carried to the second column 47b and completely separated. In the sample gas from which the components contained in the second column 47b have been completely separated, the separated components independently pass through the detector 48, and the respective amounts are detected.

The conventional gas chromatograph is constructed as described above, and since the analyzer valve 4 has a structure in which the gas flow paths can be switched, the movable part is kept airtight by a Kapton seal or the like. Further, for example, the connecting portion of the needle valve 206 of the sample conditioner 200 and the connecting portion of the measuring pipe 46, the first column 47a, the second column 47b, etc. of the analyzer valve 4 are made of O-ring such as synthetic rubber. Keeps airtightness.

[0013]

Conventionally, as described above, the following problems have been encountered. When the gas to be measured contains corrosive substances such as H ₂ S and SO ₂ , the above-mentioned member for maintaining the airtightness of the connection part deteriorates by touching those gases, and that part More gas could leak into the module.
Thus, the leak of corrosive gas can damage other parts of the module, such as the detector. In addition, if such a leak occurs, the accuracy and reliability of the measurement result will decrease.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to prevent a gas from leaking from a pipe connecting portion into a module (container) by measuring corrosive gas. The purpose is to be able to detect.

[0015]

The gas chromatograph of the present invention is provided with a gas pipe for collecting and extracting the leaked gas into the container and introducing it into the sample introducing portion. Therefore, the state of the gas in the container can be detected.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing the configuration of a gas chromatograph according to Embodiment 1 of the present invention. In the figure, 13 is a gas pipe, 13a is a gas intake part for taking in the gas in the analyzer part 100 in the gas pipe 13, and 13b is a gas intake part for taking in the gas in the sample conditioner part 200 in the gas pipe 13. . And, 14 is connected to the gas pipe 13 and the gas intake part 13 is connected.
A pump for taking in the gas from a and 13b, and a reference numeral 15 is a three-way switching unit for connecting the sample gas line and switching the flow path in order to use the gas taken in the gas pipe 13 as the sample gas.

The operation of this gas chromatograph will be described below. In particular, the operation at the time of gas leak detection will be described. As described above, in the normal operation, when the leakage from each connection portion occurs, the analyzer unit 10
0 or the sample conditioner unit 200 is filled with the leaked gas. Here, first, the three-way switching unit 15 is switched so that the gas pipe 13 is connected to the sample gas system. Then, the pump 14 is operated to take in the gas in the analyzer section 100 and the sample conditioner section 200, and the taken-in gas is used as a sample, and thereafter the measurement is performed as usual.

As a result of this measurement, if a component similar to the sample that has been taken in through the sample gas inlet 201 is detected, it can be determined that leakage has occurred. Here, if a valve is attached to the gas intake parts 13a and 13b of the gas pipe 13 and the intake of gas in the analyzer part 100 and the sample conditioner part 200 is switched, in which region the leak has occurred? Can be distinguished.

Embodiment 2. By the way, in the above embodiment, the pump 14 separates the gas in the analyzer unit 100 and the sample conditioner unit 200, but the present invention is not limited to this. FIG. 2 is a configuration diagram showing a configuration of a gas chromatograph according to Embodiment 2 of the present invention. In the figure, 16 is a carrier gas supply valve, and other reference numerals are the same as in FIG.

In the second embodiment, when a gas leak is detected, the three-way switching unit 15 is switched and the carrier gas supply valve 16 is operated to operate the analyzer unit 10.
0 and a carrier gas is supplied into the sample conditioner unit 200. As a result, the pressure in the analyzer section 100 and the sample conditioner section 200 rises,
In order to reduce this pressure, the gas inside is taken into the gas pipe 13 through the gas intake portions 13a and 13b. Then, the taken-in gas is guided to the analyzer valve 4 through the three-way switching section 15, and its components are analyzed.

From the above, the first embodiment described above
Similarly, it becomes possible to detect a leak in the analyzer unit 100 and the sample conditioner unit 200. Note that, also in this second embodiment, if the carrier + supply destination in the carrier gas supply valve 16 can be switched and the carrier gas supply to the analyzer unit 100 and the sample conditioner unit 200 can be switched, Analyzer section 100 and sample conditioner section 20
Zero gas leak detection can be performed individually.

[0022]

As described above, according to the present invention, the gas pipe for collecting the leaked gas in the container, taking it out and introducing it into the sample introducing section is provided. It is possible to analyze the components of the gas. Therefore, it is possible to measure whether or not the sample gas is leaking inside the container, and it is possible to solve the problem caused by the leakage of the sample gas.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a gas chromatograph according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a configuration of a gas chromatograph according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a configuration of a conventional gas chromatograph.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pressure reducing valve, 2a ... Supply solenoid valve, 2b ... Discharge solenoid valve, 3 ... Pressure sensor, 4 ... Analyzer valve, 8 ... Valve drive solenoid valve, 9 ... A / D converter, 11 ... CPU, 12
... solenoid valve drive section, 13 ... gas piping, 13a, 13b ... gas intake section, 14 ... pump, 15 ... three-way switching section, 1
6 ... Carrier gas supply valve, 44 ... Carrier gas introducing section,
45 ... Sample injection part, 46 ... Measuring pipe, 47a ... First column, 47b ... Second column, 48 ... Detector, 49 ... Discharge pipe, 100 ... Analyzer part, 200 ... Sample conditioner part, 201 ... Sample gas introduction Part, 202 ... standard gas introducing part, 203 ... bypass filter, 204 ... flow path switching part, 205 ... sample filter, 206, 207
... needle valve, 208,209 ... flowmeter, 210 ... thermometer.

Claims (3)

[Claims] 1. A carrier gas is introduced into the column by a flow path including a column and a detection unit arranged in a container, and a sample introduction unit is arranged in the middle, and the carrier gas is introduced into the carrier gas from the sample introduction unit. Mix the sample gas to be measured,
In the gas chromatograph in which this sample gas is separated into each component by the column and then the concentration is detected by the detection unit for each of the components, the gas leaked into the container is collected and taken out to the sample introduction unit. A gas chromatograph, characterized in that it is provided with a gas pipe to be introduced into. 2. The gas chromatograph according to claim 1, wherein a pump for feeding the gas in the container to the sample introducing portion is provided in the gas pipe. 3. The gas chromatograph according to claim 1, wherein a gas introduction unit for introducing a gas for increasing the internal pressure of the container is provided in the container.