JP3132542B2 - Analysis gas intake circuit - Google Patents

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 analyzer without changing the composition ratio when measuring the composition ratio of a non-azeotropic mixed liquefied gas. is there.

[0002]

2. Description of the Related Art Conventional methods for taking an analysis gas into a gas chromatography analyzer include the following: a) A sample is injected into a sample vaporization chamber with a syringe or the like and gasified to atmospheric pressure, and then a bypass having a variable flow path resistance is used. A method in which a small amount of a sample is sent together with a carrier gas to a separation tube by a splitter having: b) a sample container and a sample vaporization chamber are connected by a valve or the like,
There is a method in which a part is directly injected from a sample container into a sample vaporization chamber without using a syringe or the like, gasified to atmospheric pressure, and then sent to a separation tube as in the above b).

[0003]

In recent years, refrigerants having no chlorine group have been developed for the protection of the ozone layer. Among these refrigerants, there are some existing refrigeration facilities for realizing the conventional refrigeration capacity. 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 the process line of a refrigeration cycle in which condensation and expansion are repeated, and accurately measure the composition ratio. . However, the above-mentioned conventional method for capturing an analyte gas b)
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 mixture composition ratio has already changed and accurate analytical values can be obtained. I can't. In the method a), the sample is sampled as a liquid, the whole amount is vaporized, and a small amount of a part of the sample is sent to the separation tube. Therefore, the initial composition ratio is maintained, but the sample is a high-pressure gas. Conventional syringes cannot be used structurally. In a method that is not directly connected to the process line to be measured even if the structure is improved to a usable structure, the utility value is extremely reduced in view of the simultaneity of measurement. Further, the above a),
b) In either method, the sample is released to the 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 provides a method for measuring the composition ratio of a non-azeotropic mixed liquefied gas, which can be directly connected to a process line to be measured or a sample container, and does not change the initial composition ratio of the sample. It is an object of the present invention to provide an analysis gas take-in circuit which can send a required minute amount to a separation pipe of an apparatus and can correct output fluctuation due to 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 pipe having a volume V1 for liquid sealing a sample. B) a vaporization chamber provided immediately after the solenoid valve B and having a volume V2 for vaporizing a liquid-sealed volume V1 sample; c) a solenoid valve A at the start of analysis gas intake It has the function of purging the residual gas in all the lines up to the electric six-way valve and the 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. A) a motorized flow control valve and a pressure sensor; and d) a motorized six-way valve having a switching function for sending the pressure-reduced analysis gas to a detection circuit including a flow control splitter, a separation tube, and a detector. An object of the present invention is to provide a gas analysis circuit for solving the above-mentioned problems.

[0005]

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

FIG. 1 shows an analysis gas take-in circuit according to the present invention and a detection circuit in order to explain the operation.
Before the start of analysis gas intake, the electric six-way valve (7 a to f)
The port is

As shown by a solid line in FIG. 1, the connection between ab, between cd and between ef is connected, the solenoid valve A (2) is closed, and the solenoid valve B (4) and the motorized flow control valve (6) are open. In this state, the flow path from the solenoid valve A (2) to the electric flow control valve (6) is open in one direction. At this time, the detection circuit is connected to the port cd connected to the electric six-way valve (8).
Through the sample connection port (1) to the motorized flow control valve (6)
Constitutes a flow path independent of the take-in circuit constituted by. When the solenoid valve A (2) is opened after connecting the sample connection port (1) to the line to be measured or the sample container, the flow from the sample connection port (1) to the motorized flow control valve (6) is caused by the pressure of the vaporized gas. The road is purged of residual air. Next, when the solenoid valve B (4) and the electric flow control valve (6) are closed, the space between the sample connection port (1) and the solenoid valve B (4) is liquefied and settled down to an equilibrium state, and the solenoid valve B (4) The space between the sample and the electric flow control valve (6) is filled with the replaced sample gas. This gas is a gas whose mixture composition ratio has already changed, and is at a pressure close to the atmospheric pressure. Next, the solenoid valve A (2)
When the valve is closed, the entire system from the line to be measured or the sample container to the solenoid valve B (4) is gas-phased in the liquid-sealed conduit (3) connected between the valve and the solenoid valve B (4). The liquefied sample when the liquid phase and the liquid phase are in an equilibrium state is confined.
If it is sent to 0), the analysis gas is taken in without changing the mixture composition ratio. The vaporizing chamber (5) provided immediately after the solenoid valve B (4) is for vaporizing the liquefied sample sealed in the liquid sealing tube (3), and has a volume V2 and an electromagnetic excluding the vaporizing chamber. Valve B (4) to electric flow control valve (6)
And the volume V1 of the liquid seal pipe (3),
The relationship between the volume V1 and 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 in the above equation is the amount discharged from the electric flow control valve (6). It is. After the liquefied sample is taken into the liquid ring conduit (3), when the solenoid valve B (4) and the electric flow control valve (6) are opened, the sample is vaporized in the vaporization chamber (5), and the above equation is satisfied. Any gas having a changed composition ratio remaining in the pipeline is purged. A pressure sensor (7) provided between the vaporization chamber (5) and the motorized flow control valve (6) automatically detects when the gas pressure in the pipeline becomes almost equal to the carrier gas pressure. The motorized flow control valve (6) is closed and the motorized six-way valve (8) is closed.

FIG. 1 shows the connections indicated by broken lines, ie bc and de
When the ports are switched to connect the ports of and, 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 in the liquid sealing pipeline between the two solenoid valves A and B from the line to be measured or the sample container in an equilibrium state. Since it can be sent, accurate composition analysis is possible without changing the composition ratio of the non-azeotropic mixed liquefied gas. In addition, the analysis can be started only by connecting the line to be measured or the sample container directly to the sample connection port, and no intermediary container is required, realizing the simultaneity of the analysis and the simple operation. Further, since the analysis gas pressure is measured, the analysis result can be normalized excluding the factor due to the fluctuation of the atmospheric pressure.

[0007]

[Brief description of the 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 pipeline 4 ... Solenoid valve B 5 ... Vaporization chamber 6 ... Electric flow control valve 7 ····· Pressure sensor 8 ···· Electric six-way valve 9 ··· Splitter 10 ··· Separation tube

Claims (1)

(57) [Claims] 1. An electromagnetic valve A directly connected to a sample container or the like, an electromagnetic valve B provided via a liquid-sealing conduit for liquid-sealing the sample, and a vaporization chamber provided immediately after this for evaporating the entire liquid-sealed sample. , A pressure sensor and an electric flow control valve that control the pressure of the vaporized analysis gas to the same level as the pressure of the carrier gas, and a switching function to send the pressure-reduced analysis gas to the detection circuit A liquid chromatograph comprising a liquid sample in a sample container and the like in an equilibrium state by operating an electromagnetic valve and a motorized flow rate control valve, gasifying the entire amount of the liquid, and then partially gasifying a small amount thereof. The analysis tube can be analyzed without changing any composition ratio in the process of taking in the analysis gas, and it is suitable for non-azeotropic liquefied gas composition analysis. An analysis gas take-in circuit having a correction capability for fluctuations in pressure.