JPH0943216A - Analyzing gas intake circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an analyzing gas intake circuit which can directly connect to a process line or a sample vessel to be measured and send the gas in a necessary small amount to the separation pipe of a gas chromatography analyzer without changing sample composition ratio in equilibrium state to measure the compositions of azeotropic mixture liquified gas and enables correcting the variation in the analyzed values due to pressure variation in the analyzing gas. SOLUTION: Provided are a solenoid valve A2 directly connected to a sample vessel, solenoid valve B4 placed by way of a liquid sealed channel, 3 sealing the sample, and an evaporation room 5 placed immediately afterward to evaporate al-l of liquid sealed sample. The circuit is constituted of a pressure sensor 7, an electrically operated flow control valve 6 which has a capability of controlling the pressure of the evaporated analyzing gas to be similar to the pressure of the carrier gas and an electric 6-way valve 8 having a switching function for sending the depressurized analyzing gas to a detection circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for taking an analysis gas into a gas chromatography analysis device or the like without changing the mixture composition ratio when measuring the composition ratio of a non-azeotropic mixture liquefied gas. is there.

[0002]

2. Description of the Related Art A conventional method for taking an analysis gas into a gas chromatography analysis apparatus is as follows: a) A sample is injected into a sample vaporization chamber by a syringe or the like to be gasified to atmospheric pressure, and then a bypass having a variable flow path resistance is used. And a method of sending a fixed amount of a small amount of sample to a separation tube together with a carrier gas with a splitter having a
There is a method in which a part of the sample container is directly injected into the sample vaporization chamber without using a syringe or the like and gasified to atmospheric pressure, and then sent to a separation tube in the same manner as in b) above.

[0003]

In recent years, refrigerants having no chlorine group have been under development for protection of the ozone layer. Among these alternative refrigerants, existing refrigeration equipment is required to realize conventional refrigerating capacity. However, many are unavoidable as non-azeotropic mixtures. Therefore, it is an urgent task in the refrigerating machine industry to easily sample such a non-azeotropic mixed liquefied gas from a process line of a refrigeration cycle in which condensation and expansion are repeated and to accurately measure its composition ratio. . However, the above-mentioned conventional method for introducing the analyzed gas b)
However, at the moment when a part of the sample is taken from the sample container into the sample vaporization chamber, the equilibrium between the gas phase and the liquid phase is broken, and since it is non-azeotropic, the initial mixed composition ratio has already changed and an accurate analysis value can be obtained. I can't. In the method a), the liquid is sampled, the whole amount is vaporized, and a small amount of a part of the liquid is sent to the separation tube, so that the initial composition ratio is maintained, but the sample is a high-pressure gas. Conventional syringes cannot be structurally used. Even if the usable structure is improved, the method that is not directly connected to the process line to be measured greatly reduces the utility value in terms of measurement simultaneity. Furthermore, the above a),
b) In both methods, the sample is released to atmospheric pressure and gasified, so that the analysis output result varies depending on the analysis gas pressure. In view of the above situation, the present invention, when measuring the composition ratio of the non-azeotropic mixed liquefied gas, can be directly connected to the process line to be measured or the sample container and without changing the initial composition ratio of the sample, gas chromatography analysis It is an object of the present invention to provide an analysis gas intake circuit capable of sending a necessary minute amount to a separation tube of an apparatus and compensating an output fluctuation due to an analysis gas pressure.

[0004]

In order to achieve the above object, the present invention provides: (a) a solenoid valve A directly connected to a process line to be measured or a sample container, and a liquid-sealing conduit having a volume V1 for liquid-sealing a sample. And (b) a vaporization chamber that is provided immediately after the solenoid valve B and has a volume V2 for vaporizing a liquid-sealed volume V1 sample, and c) from the solenoid valve A when starting the analysis gas intake. It has a function of purging the residual gas in all the pipes up to the electric six-way valve (d), which will be described later, and a function of controlling the pressure of the analysis gas vaporized in the vaporization chamber to the same level as the pressure of the carrier gas. Separated by a motorized flow control valve and pressure sensor, and d) a motorized six-way valve having a switching function for sending the pressure-reduced analysis gas to a flow control splitter and a detection circuit consisting of a separation tube and a detector. This is to solve the above-mentioned problems by forming a deposition gas intake circuit.

[0005]

Operation and Embodiments The operation and embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an analysis gas intake circuit according to the present invention and a detection circuit for explanation of operation.
Before starting the analysis gas uptake, the motorized six-way valve (7 a to f
Port of

As shown by the solid line in FIG. 1, ab, cd and ef are connected, solenoid valve A (2) is closed and solenoid valve B (4) and electric flow control valve (6) are open. In the state, the electromagnetic valve A (2) to the electric flow rate control valve (6) is a flow path opened in one direction. Further, at this time, the detection circuit has a port cd connected to the electric six-way valve (8).
Via the sample connection port (1) to the electric flow control valve (6)
The flow path is independent of the intake circuit composed of. When the solenoid valve A (2) is opened after the sample connection port (1) is connected to the line to be measured or the sample container, the flow from the sample connection port (1) to the electric flow control valve (6) is caused by the pressure of the vaporized gas. The residual air in the tract is purged. Next, when the solenoid valve B (4) and the electric flow rate control valve (6) are closed, the sample connection port (1) and the solenoid valve B (4) are liquefied and settled in an equilibrium state, and the solenoid valve B (4) The space between the electric flow control valve (6) and the electric flow control valve (6) is filled with the replaced sample gas. This gas is a gas whose mixed composition ratio has already changed, and is at a pressure close to atmospheric pressure. Next, solenoid valve A (2)
When closed, the whole system from the line to be measured or the sample container to the solenoid valve B (4) is in the gas phase in the liquid ring conduit (3) connected between this and the solenoid valve B (4). This means that the liquefied sample when the liquid phase and the liquid phase are in equilibrium is confined, and this is completely gasified, and a small amount of it is separated into a separation tube (1
If it is sent to 0), the analysis gas is taken in without changing the mixed composition ratio. The vaporization chamber (5) provided immediately after the solenoid valve B (4) is for vaporizing the liquefied sample enclosed in the liquid sealing tube (3), and its volume V2 and the electromagnetic chamber excluding the vaporization chamber From valve B (4) to electric flow control valve (6)
The volume VP of the pipeline up to and the volume V1 of the liquid ring pipeline (3),
The relation with the volume V when the liquefied sample of volume V1 is completely vaporized at the same pressure as the carrier gas is V> V1 + V2 + VP, and the difference between both sides of the above equation is the amount discharged from the electric flow control valve (6). Is. When the solenoid valve B (4) and the electric flow rate control valve (6) are opened after the liquefied sample has been taken into the liquid-sealing pipe (3), the sample is vaporized in the vaporization chamber (5), and the above formula has the relationship. Any gas whose composition ratio has changed in the pipeline is purged. A pressure sensor (7) provided between the vaporization chamber (5) and the electric flow rate control valve (6) automatically detects when the gas pressure in the pipeline has reached the same level as the carrier gas pressure. Close the electric flow rate control valve (6) to the electric six-way valve (8)

1 is a connection indicated by a broken line in FIG. 1, that is, bc and de
When the ports of and and fa are switched so as to be connected, a minute amount of the analysis gas is branched by the splitter (9) together with the carrier gas and sent to the separation tube (10). The output of the pressure sensor at this time is used as a correction value when normalizing the analysis result.

[0006]

The effects of the present invention are as follows. A liquefied sample can be taken from the line to be measured or the sample container in an equilibrium state into the liquid-sealed pipe between the two solenoid valves A and B. After completely gasifying the liquefied sample, part of it is transferred to a separation tube Since it can be sent, accurate composition analysis is possible without changing the composition ratio of the non-azeotropic mixed liquefied gas. Further, the analysis can be started only by directly connecting the line to be measured or the sample container to the sample connection port, and since no mediating container is required, the simultaneous analysis and the simplicity of the operation are realized. Further, since the analysis gas pressure is measured, the analysis result can be normalized by removing the factor due to the change in atmospheric pressure.

[0007]

[Brief description of drawings]

FIG. 1 is a circuit diagram of an analysis gas intake circuit of the present invention and a detection circuit for explaining the operation.

[Explanation of symbols]

 1 ... Sample connection port 2 ... Solenoid valve A 3 ... Liquid sealing conduit 4 ... Solenoid valve B 5 ... Vaporization chamber 6 ... Electric flow rate control valve 7 ··· Pressure sensor 8 ··· Electric six-way valve 9 ··· Splitter 10 ··· Separation pipe

Claims (1)

[Claims] 1. A solenoid valve A directly connected to a sample container and the like, a solenoid valve B provided via a liquid-sealing pipe for liquid-sealing a sample, and a vaporization chamber provided immediately after this for vaporizing the entire liquid-sealed sample. , A pressure sensor and an electric flow rate control valve that work to control the pressure of the vaporized analysis gas to the same level as the pressure of the carrier gas, and a switching function for sending the analysis gas of reduced pressure to the detection circuit And a motorized six-way valve, which is operated by a solenoid valve and a motor-operated flow control valve to liquid-seal a sample such as a sample container in an equilibrium state and completely gasify it, and then a small amount of a gas chromatographic analyzer By sending it to the separation tube of, it is possible to analyze without changing the composition ratio in the analysis gas uptake process, and it is suitable for non-azeotropic liquefied gas composition analysis. An analytical gas uptake circuit characterized by having a correction capability for fluctuations in pressure.