JPH0372328B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a gas permeable membrane module, and particularly to a gas permeable membrane module using a gas permeable membrane for obtaining a gas enriched with a specific component from a mixed gas. .

BACKGROUND OF THE INVENTION In recent years, oxygen-enriched gas has been widely used for combustion, medical purposes, vegetable gardening, fish farming, etc. Oxygen separation by cryogenic separation is a common method for obtaining oxygen-enriched gas, and other typical methods include:
There is a method that utilizes gas adsorption and desorption on a fixed surface (zeolite, etc.). Further, in order to easily produce oxygen-enriched gas, gas permeable membranes using polymer membranes are being actively developed.

As a conventional selective gas permeable membrane module using a polymer membrane, there is a structure as shown in, for example, Japanese Utility Model Application Publication No. 56-68929.

Hereinafter, a conventional gas permeable membrane module will be explained with reference to FIG. Note that this figure shows a structure in which two gas permeable membrane modules are stacked.

In the figure, reference numeral 8 denotes a communicating body having air permeability, which holds a gas permeable membrane 11 for selectively separating a mixed gas from the inside. 9 is a breathable sheet arranged on both sides of the communication body 11; 10 is a module frame forming an outer wall; 10a is a groove through which the gas separated by the gas permeable membrane 11 passes; 12 is the gas permeable membrane 11
4b is a module pitch when the gas permeable membrane 11 is laminated.

FIG. 7 is a perspective view of a state in which two conventional gas permeable membrane modules are laminated, before a gas permeable membrane is attached.

In the figure, 13 is a gas outlet for taking out the permeated gas.

FIG. 8 is a longitudinal sectional view of a conventional gas permeable membrane module.

The operation of the gas permeable membrane module configured as described above will be explained below.

In FIG. 8, when the inside of the gas permeable membrane module is first depressurized and suctioned from the gas outlet 13 with a vacuum pump, specific gas components in the gas outside the gas permeable membrane module are absorbed by the gas permeable membrane 11. Selectively separated. The selectively separated gas is taken out from the gas outlet 13 from the breathable sheet 9 through the vent 8.

The air permeable sheet 9 is for protecting the gas permeable membrane 11 from being damaged since the surface of the communicating body 8 is rough, and when the gas permeable membrane 11 is depressurized by a vacuum pump, the communicating body It is placed on both sides of the communication body 8 so as not to bite into the fine irregularities on the surface of the communication body 8.

Furthermore, the reason why the module frame 10 is attached to the outer periphery of the communication body 8 to form an outer wall is because there is no means to keep the gas permeable membrane 11 airtight with the communication body 8 alone. This brings the gas outlet 13 and the communication body 8 into communication.

Problems to be Solved by the Invention However, as shown in FIG.
2, when the pressure is not reduced by the vacuum pump under high temperature and high humidity conditions, the central portion of the breathable sheet 9 on both sides of the communication body 8 bulges, and tension is applied to the gas permeable membrane 11. The gas permeable membrane 11 will be damaged. As a result, the life of the gas permeable membrane module is shortened.

Furthermore, when the air permeable sheets 9 disposed on both sides of the communication body 8 swell, the gas permeable membranes 11 of other opposing permeable membrane modules in which the gas permeable membranes 11 are laminated in the thickness direction come into contact with each other, causing the gas permeable membranes 11 to come into contact with each other. 11 is damaged. Therefore, the module pitch 4b must be made large enough so that the gas permeable membrane 11 does not come into contact with it, and the gas permeable membrane module cannot be made smaller.

In view of the problems encountered with conventional gas permeable membrane modules, the present invention aims to provide a gas permeable membrane module that has a long life and is small in size.

Means for Solving the Problems In order to achieve this object, in the gas permeable membrane module of the present invention, a gas permeable sheet or a vent with a smoother surface than the gas permeable sheet or gas permeable body is provided on both sides of the communicating body sandwiched between the gas permeable membranes. The communication body is integrally molded or entirely glued.

Effect With this configuration, the breathable sheet does not inflate at high temperatures and high humidity without being subjected to reduced pressure from the vacuum pump, so the gas permeable membranes do not come into contact with each other, and there is no tension on the gas permeable membranes. It doesn't cost. As a result, the life of the gas permeable membrane module is extended.
Furthermore, since the gas permeable membrane does not swell, the module pitch of the gas permeable membrane module can be small.

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

Example 1 FIG. 1 is a cross-sectional view of two gas permeable membrane modules stacked together in the first example of the present invention.
FIG. 2 is a perspective view showing the gas permeable membrane module in a state before the gas permeable membrane is attached, and FIG. 3 is a cross-sectional view of the gas permeable membrane module.

In FIG. 1, reference numeral 1 denotes a communicating body, which is formed by thermally curing continuously foamed ether-based urethane foam with an impregnating agent 3 and press-molding it. Reference numeral 2 denotes an air permeable sheet of polyethylene woven fabric, which is entirely adhered to both sides of the communication body 1 by integral press molding therewith. 3 is an impregnating agent (methyl diisocyanate) for bonding the entire surface of the communicating body 1 and the breathable sheet 2 together by integral pressing. 4
is a module frame made of hard vinyl chloride resin, which is formed by extrusion molding, pultrusion molding, injection molding, etc., and a groove 4a is provided on the inside adjacent to the communicating body 1 to allow permeated gas to pass through. 4b is a module pitch when gas permeable membrane modules are stacked, 5 is a silicone resin gas permeable membrane that selectively separates a mixed gas, and 6 is a double-sided tape for keeping the gas permeable membrane 5 and module frame 4 airtight. For example, Nitto 505, a product of Nitto Electric Industry Co., Ltd., can be used.

In FIG. 2, 7 is a gas outlet for taking out the permeated gas.

In FIG. 3, arrows indicate the direction of flow of permeate gas when the pressure is reduced by a vacuum pump.

The operation of the gas permeable membrane module configured as described above will be described below.

First, when the inside of the gas permeable membrane module is depressurized and suctioned using a vacuum pump from the gas outlet 7, specific gas components of the gas outside the gas permeable membrane module are selectively separated by the gas permeable membrane 5, and the gas permeable membrane Infiltrate inside the module. Then, the permeated gas flows inside the gas permeable membrane module as shown by the arrow in FIG. 3, and the permeated gas is obtained from the gas outlet 7.

The air permeable sheet 2 has a rough surface on the communicating body 1, and is used to protect the gas permeable membrane 5 from the rough surface.When the gas permeable membrane 5 is suctioned under reduced pressure by a vacuum pump, the gas permeable membrane 5 is formed on the surface of the communicating body 1. This is to prevent it from digging into unevenness.

In addition, the module frame 4 constituting the outer wall is provided with a groove 4a on the inner side adjacent to the communication body 1, and this groove 4a efficiently transmits the degree of vacuum to the inside of the module when vacuum suction is performed using a vacuum pump. The permeate gas is guided to the gas outlet 7.

Then, the gas-permeable membrane 5 is adhesively sealed with double-sided tape 6 to keep the inside of the gas-permeable membrane module airtight and prevent gas from entering from other than the gas-permeable membrane 5 when vacuum suction is performed using a vacuum pump. .

FIG. 5 is a comparison diagram showing the lifespan of the gas permeable membrane module of the present invention and a conventional gas permeable membrane module due to deterioration in oxygen concentration.

As shown in the figure, when the air permeable sheet 2 is integrally molded or adhered to substantially the entire surface on both sides of the communicating body 1, the temperature is 60°C and the relative humidity is 95°C, compared to the conventional gas permeable membrane module, according to experiments conducted by the inventors. % doubles the lifespan.

However, the life of the gas permeable membrane module was determined to be until the oxygen concentration became 28% or less.

In this way, according to this embodiment, the breathable sheets 2 are placed on both sides of the communicating body 1, and the entire surface is bonded by pressing them together with the impregnating agent 3. Therefore, unlike the conventional products, the breathable sheets 2 As a result, the gas permeable membrane 5 swells, and the gas permeable membranes no longer come into contact with each other or are subject to tension, thereby extending the life of the gas permeable membrane module.

Since the gas permeable membrane 5 does not bulge, the module pitch 4b of the gas permeable membrane module can be reduced, so that if the performance is equivalent to that of a conventional product, it can be made smaller.

Embodiment 2 FIG. 4 is a cross-sectional view of a gas permeable membrane module in a second embodiment of the present invention.

In the figure, 1 is a communication body, 4 is a module frame forming an outer wall, 4a is a groove for passing permeated gas,
5 is a gas permeable membrane, and 6 is a double-sided tape, which are substantially the same components as in the first embodiment.

Reference numeral 2a denotes a communicating body whose surface is smoother than that of the communicating body 1 in order to protect the gas permeable membrane 5.

The operation of the gas permeable membrane module configured as described above is the same as that of the first embodiment, and by making the part of the breathable sheet 2 into a communicating body 2a with a smooth surface, it can be operated as the same as that of the first embodiment. The same effect can be obtained and the same performance can be obtained.

On the other hand, by forming the entire communication body 1 into a dense communication structure that does not damage the gas permeable membrane 5, the communication body 1
I thought that it might be possible to eliminate the need for a, and tried a test, but the flow resistance (pressure drop) was large and the gas permeable membrane module performance (oxygen enriched flow rate,
The result was that the oxygen concentration (oxygen concentration) was significantly impaired. Therefore, the communicating body 1 needs to be sufficiently roughened. Furthermore, in order to protect the gas permeable membrane 5, it is practical to use the breathable sheet 2 or the communicating body 2a with a smooth surface.

Effects of the Invention As described above, the present invention improves the conventional products by substantially integrating a breathable sheet or a communicating body and a communicating body with a smoother surface on both sides of the communicating body. It is possible to eliminate the fear that the air-permeable sheet or the communication body, which is smoother than the communication body, will swell. In this way, since there is no fear that the gas permeable membranes will come into contact with each other, the module pitch of the gas permeable membrane module can be reduced, the device can be made smaller, and its life can be extended.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of two stacked gas-permeable membrane modules according to the first embodiment of the present invention, FIG. 2 is a perspective view of the same gas-permeable membrane module before the gas-permeable membrane is attached, FIG. 3 is a longitudinal sectional view of the same gas permeable membrane module. FIG. 4 is a cross-sectional view of a gas permeable membrane module according to a second embodiment of the present invention. FIG. 5 is a life comparison diagram of the gas permeable membrane module of the present invention and a conventional gas permeable membrane module. Fig. 6 is a cross-sectional view of two conventional gas permeable membrane modules stacked together, Fig. 7 is a perspective view of two conventional gas permeable membrane modules stacked together before the gas permeable membrane is attached, and Fig. 8 The figure is a longitudinal sectional view of a conventional gas permeable membrane module. 1... Connecting body, 2... Breathable sheet, 2a...
A communicating body with a smooth surface, 3... Impregnating agent, 5... Gas permeable membrane.

Claims (1)

[Claims] 1. A gas-permeable membrane that selectively separates the atmosphere or a mixed gas, a communicating body that holds the gas-permeable membrane from the inside and has air permeability, and a module frame that forms an outer wall. A breathable sheet or a communicating body having a smoother surface than the communicating body is integrally molded or adhered to substantially the entire surface between the communicating body and on both sides of the communicating body sandwiched between the gas permeable membranes. A gas permeable membrane module interposed therebetween.