JPH0262013B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for measuring the selective permeability of a high-pressure mixed gas in a film sample, and more specifically, an apparatus for measuring the selective permeability of a high-pressure mixed gas in a film sample using a gas chromatograph. The present invention relates to a transmittance measuring device.

When a pressurized mixed gas permeates through a film sample, it is expected that the interaction between the film and the gas will change the selective permselectivity for the film sample, unlike in the case of a low-pressure state. It is desired to establish a method for measuring the selective permeability of gases. However, with conventional devices, the supply pressure of the mixed gas can only be raised to about 10 atm at most, making it completely inapplicable to the selective permeability measurement of the above-mentioned high-pressure mixed gas.

The present invention aims to provide a gas permeability measuring device that can satisfy the above-mentioned requirements for selective permeability measurement of a high-pressure mixed gas and can accurately sample permeated gas.

The transmittance measuring device of the present invention is equipped with a permeation cell in which a supply chamber and a permeation chamber are partitioned on both sides by mounting a film sample, and a plurality of high-pressure gases are supplied to the supply chamber at a predetermined mixing ratio. A circulation path for supplying a high-pressure mixed gas while circulating is connected to the permeation chamber, and a permeation gas sampling system having a safety valve for preventing abnormal pressure increase is connected to the permeation chamber.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the high-pressure mixed gas selective permeability measuring device according to the present invention, which is particularly suitable for measuring the selective permeability of a film sample with a relatively low transmittance by using a reduced pressure method. This is an example of the present invention.

The mixed gas supply system in this transmittance measuring device includes cylinders 1 and 2 into which multiple types of gases to be mixed are pressurized, and these cylinders 1 and 2 are mixed via needle valves 3 and 4 and valves 5 and 6. It is connected to the first and second connection ports 11 and 12 of the tank 7. For example, this tank 7 has a capacity of 5 and a pressure resistance of 150.
Kg/cm ² can be used.

the third and fourth connection ports 13 of the mixing tank 7;
A mixed gas circulation path 8, whose flow path is indicated by an arrow, is formed between 14 and 14. This circulation path 8 is for circulating and supplying the mixed gas to a supply chamber 9a defined on one side of the permeation cell 9 by mounting the film sample 10 thereon. , 18 and a relay pipe 19, etc., to the inlet of the supply chamber 9a, and its outlet is connected to the fourth connection port 14 of the mixing tank 7 through a relay pipe 21, a valve 22, a circulation pump 23, and a valve 24. . The circulation pump 23 is, for example, a variable flow rate magnet type with a capacity of 0 to 300ml/
The min value can be used. Further, between the valves 17 and 18 in the circulation path 8, valves 26 and 27 are connected for branching the circulation path 8, and the valve 26 connects the third connection port 13 and the second connection port 12.
In order to enable communication between the valve 22 and the valve 27, to short-circuit the circulation path 8, and to create a vacuum in the mixed gas supply system including the circulation path 8, the valve 22
A rotary vacuum pump 29 is connected through a valve 28 to the circulation pump 23, and this pump 29 is connected to the fifth connection port 15 of the mixing tank 7 through a valve 30.

In addition, in order to analyze the components of the mixed gas flowing through the circulation path 8 as necessary, a part of the circulation path 8 is branched so that the mixed gas can be introduced into the TCD gas chromatograph 31. The relay pipe 21 and the valve 22 are connected to a first connection port 41 of a flow path switching valve 33 via a needle valve 32. This switching valve 33 is configured so that the flow path between each connection port can be switched between the state shown by a solid line and the state shown by a broken line in the figure, and the second and fifth connection ports 4
A gas sampler 34 for the high pressure side is connected between the gas sampler 34 and the gas sampler 34 for the high pressure side, and the sixth connection port 46 can be opened to the outside via the valve 35, etc., and the third and fourth connection ports 43 and 44 are connected to the gas chromatograph 31. It is connected to three-way valves 38 and 39 of a sample gas supply path 37 leading to the sample gas supply path 37.

A permeation gas sampling system is connected to a permeation chamber 9b defined on the opposite side of the film sample 10 in the permeation cell 9. By creating a vacuum inside the system, this sampling system
This system is configured to eliminate as much as possible the interfering gas unrelated to quantitative determination remaining in the system to enable highly sensitive quantitative determination, and to promote the permeation of the mixed gas through the film sample 10. This sampling system includes a safety valve 48 connected to the permeation chamber 9b of the permeation cell 9 via a relay pipe 47 to prevent abnormal pressure rise. Above safety valve 4
Reference numeral 8 is constructed as a check valve that relieves and exhausts the excess gas to the outside when the gas pressure in the pipe exceeds a set pressure.

Further, the relay pipe 47 includes a low-pressure gas reservoir 50 for accumulating permeated gas, valves 51, 52, 5
3 to a rotary type vacuum pump 54, the pump 54 can evacuate the system to a vacuum state, and the degree of vacuum can be measured with a Pirani vacuum gauge 55 installed in the middle. There is. Further, the valve 5 is connected between the pair of valves 51 and 52.
7 to a gas sample tube 58 for sampling the permeated gas, one end of the tube 58 is connected to the sample gas supply path 37 via a valve 59, and the other end is connected to the sample gas supply path 37 via a valve 60. connection to a three-way valve 61 in channel 37, thereby allowing this sample tube 5 to
The permeated gas can be sampled in the chamber 8 and supplied to the gas chromatograph 31.

As the valves 51, 52, 57, 59, and 60, bellows valves with high sealing properties are used to achieve a high degree of vacuum within the permeated gas sampling system. In the permeate gas sampling system of conventional devices, the above-mentioned valves use general-purpose low-sealing structures, so gas leaks occur at the sliding parts of each valve in high vacuum conditions, reducing measurement accuracy. However, in the above device, by using a bellows valve, errors due to gas leakage from the valve are eliminated, and a vacuum degree of about 10 ^-3 Torr can be achieved in a blank test.

The permeation cell 9 is housed in an air constant temperature bath 62,
This constant temperature bath 62 is equipped with a heater 63 connected to an external power source (not shown) and stirring blades 65 driven by a motor 64, which keep the internal temperature at a constant temperature, for example, 10 degrees below room temperature. ℃ from higher temperature
It is possible to maintain a predetermined temperature within the range of 200℃.

To use the above transmittance measuring device, first, the mixed gas supply system is evacuated including the mixing tank 7 by the vacuum pump 29, and then the gases in the pair of cylinders 1 and 2 are mixed in a predetermined manner. The mixture is introduced into the mixing tank 7 at a predetermined supply pressure. after that,
The mixed gas is circulated in the circulation path 8 by the circulation pump 23, and in parallel with this, the inside including the gas reservoir 50 is evacuated by the vacuum pump 54 in the permeate gas sampling system. Thereby, the mixed gas circulating in the circulation path 8 passes through the film sample 10 from the supply chamber 9a of the permeation cell 9, reaches the permeation chamber 9b, and is then accumulated in the gas reservoir 50. A part of the permeate gas accumulated here is e.g.
Repeat the operations in steps 52 and 57 to remove the gas sample tube 5.
Sampled at 8. The permeate gas sampled in the gas test tube 58 in this manner is transferred to the sample gas supply pipe 37 by the carrier gas flowing in from the carrier gas inlet 31a of the gas chromatograph 31 by operating the valves 59, 60, and 61. The sample is then transferred to a gas chromatograph 31 where it is separated and quantified. Therefore, sampling and separation and quantitative determination of the permeated gas are repeated intermittently. The carrier gas that has carried the permeated gas flows out from the carrier gas outlet 31b of the gas chromatograph 31.

If the time interval at which the above separation and quantification is repeated is selected appropriately, measurements can be made in a state where the transmittance changes transiently, such as at the beginning of transmission, and measurements after the transmittance reaches a steady state. This can be carried out in detail over time, thereby making it possible to determine the transmittance more accurately. Furthermore, in the above-mentioned permeate gas sampling system, a bellows valve with high sealing performance is used as the valve 51 etc. used for sampling the permeate gas, so highly accurate measurement is possible without being affected by external gas. .

Furthermore, the separation and quantification of the mixed gas circulating in the circulation path 8 can be performed in the gas chromatograph 31 in the same way as the permeate gas by switching the flow path of the flow path switching valve 33 from the solid line to the broken line. It will be done. That is, when the flow path of the switching valve 33 is set to be switched as shown by the solid line, a part of the mixed gas flowing through the circulation path 8 flows into the switching valve 33 through the needle valve 32, and then the gas sampler 34 The mixed gas flows out through the valve 35 and the like, and the mixed gas is sampled by the gas sampler 34 at this time. After that, if the flow path of the switching valve 33 is switched as shown by the broken line, the mixed gas flowing into the switching valve 33 will be directly exhausted to the outside through the valve 35 etc., and the sample gas to the gas chromatograph 31 will be exhausted. The carrier gas flowing through the supply path 37 flows from the three-way valve 38 into the third connection port 43 of the flow path switching valve 33, causing the mixed gas in the gas sampler 34 to flow into the gas chromatograph 31 through the three-way valve 39, where the mixed gas Separation and quantification are performed. At this time, it is natural that, for example, the valves 59 and 60 in the gas sample tube 58 must be kept closed.

In the above device, the supply chamber 9a of the permeation cell 9
Since the mixed gas to be supplied to the gas is circulated in the circulation path 8 with the mixing tank 7 in the middle, even if the mixed gas is supplied at high pressure and the permeation amount of each gas is increased, the permeability of each gas is low. The change in the composition ratio of the mixed gas due to the difference in can be made small and has almost no effect on the measurement. In addition, a safety valve 4 is installed in the sampling system on the permeation chamber 9b side of the permeation cell 9.
8, even if the gas pressure on the permeation chamber side rises abnormally for some reason, the increased gas pressure will be lowered by the relief exhaust, which will keep the mixed gas pressure supplied to the supply chamber 9a sufficiently high. Measurements can be made in a safe condition even as a physical object.

FIG. 2 shows a permeated gas sampling system that implements a flow method instead of the decompression method described above, and is particularly suitable for measuring film samples with relatively high transmittance.

The above apparatus is equipped with a flow gas supply port 71 for moving the permeated gas that has passed through the film sample 10 of the permeation cell 9, and this supply port 71 is connected to a valve 72 and a relay pipe 7.
3 and the like to the inlet of the permeation chamber 9b of the permeation cell 9, and its outlet is connected to the safety valve 48 and the first connection port 81 of the flow path switching valve 76 through the relay pipe 75. Similar to the switching valve 33 in FIG. 1, this switching valve 76 is configured so that the flow path between each connection port can be switched between the one shown by a solid line and the one shown by a broken line. A gas sampler 77 for gas samples is connected between 82 and 85, and the sixth connection port 86 is opened to the outside through the valve 78 etc.
A gas flow path 79 to the gas chromatograph 31 is connected to the fourth connection ports 83 and 84.

Note that the same parts as in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In the apparatus configured as described above, sampling and separation and quantitative determination of the permeated gas are performed by switching the flow path switching valve 76. That is, the flow paths between the respective connection ports of the switching valve 76 are switched as shown by solid lines, and the flow gas inlet 7
1, when a flow gas different from the above-mentioned mixed gas is flowed at an appropriate flow rate in the range of 0 to 100 ml/min, the flow gas passes through the film sample 1 in the permeation chamber 9b.
The permeated gas that has passed through the 0 gas is allowed to flow out through the flow path switching valve 76, the gas sampler 77, the valve 78, etc., and thereby the permeated gas is sampled in the gas sampler 77. After that, wait until the permeation rate of the mixed gas reaches a steady value, and then
6 to the flow path shown by the broken line, the gas sampler 77 is connected to the sample gas supply path 37 to the gas chromatograph 31, and the permeated gas in the gas sampler 77 is thereby connected to the three-way valve by the carrier gas. 38 and 39 to the gas chromatograph 31, where it is separated and quantified.

It goes without saying that the transmittance of a single gas can be measured using the apparatus shown in FIGS. 1 and 2 above.

As is clear from the detailed description above, according to the present invention, sampling of the permeated gas that has passed through the film sample of the mixed gas can be performed with high precision and high safety even when the supply pressure of the mixed gas is set to a high pressure. This can be done under the

[Brief explanation of drawings]

FIG. 1 is a block diagram of a high-pressure mixed gas selective permeability measurement apparatus according to the present invention, and FIG. 2 is a block diagram of a different example of the permeate gas sampling system. 8... Circulation path, 9... Transmission cell, 10... Film sample, 9a... Supply chamber, 9b... Transmission chamber.

Claims (1)

[Claims] 1 A circulation system comprising a permeation cell in which a supply chamber and a permeation chamber are partitioned on both sides by mounting a film sample, and supplying a high-pressure mixed gas containing multiple types of high-pressure gas at a predetermined mixing ratio to the above-mentioned supply chamber while circulating it. 1. An apparatus for measuring selective permeability of a high-pressure mixed gas in a film sample, characterized in that a permeate gas sampling system having a safety valve for preventing abnormal pressure increase is connected to the permeation chamber.