JPH08332306A - Degassing membrane and module - Google Patents

Abstract

PURPOSE: To simply produce a degassing module by integrally providing a degassing layer composed of an air permeable and liquid impermeable membrane to both surfaces of a passage layer composed of a fluid permeable member such as a nonwoven fabric, a fabric or a knitted fabric. CONSTITUTION: Degassing layers 2 each composed of a air permeable and liquid impermeable membrane are integrally provided to both surfaces of a passage layer 1 composed of a fluid permeable member such as a nonwoven fabric, a fabric or a knitted fabric. That is, the air permeable and liquid impermeable membranes are integrally provided to both surfaces of the passage layer 1 before the end parts of the degassing layer 2 are sealed. By this constitution, the point at issue at a time of the sealing of end parts is solved. The end parts of the air permeable and liquid impermeable films may be sealed at the same time when the films are integrally provided to both surfaces of the fluid permeable member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degassing membrane and a degassing module for degassing a gas dissolved in a liquid.

[0002]

2. Description of the Related Art In general, a membrane type degassing module has a spacer, such as a net, as a flow path material placed inside two sheet-like materials that are gas permeable and liquid impermeable when forming a membrane material. The part was sealed with an adhesive or the like. Alternatively, the ends of two gas-permeable and liquid-impermeable sheet-shaped materials are sealed with an adhesive or the like to form a hollow bag-shaped membrane, and a spacer such as a net is inserted therein as a channel material. It was

[0003]

However, in the prior art, when the flow path material is put into the gas-permeable and liquid-impermeable membrane as described above and the end portion is sealed with the adhesive, curing is performed. Until then, there is a problem that the seal part cannot be moved, heat is required for curing, and it takes time.

When the end sealing is performed by heat fusion, two gas-permeable and liquid-impermeable membranes and one channel material 3 in total.
The problem is that it must be taken out from the fusing device so that the sheets are sent to the fusing device at the same time so as not to shift, and the internal flow path material does not shift or wrinkles in the gas permeable liquid impermeable film. is there. Further, when the flow path material is inserted by sealing the ends of two gas-permeable and liquid-impermeable membranes, the process and apparatus become more complicated, and even after the flow path material is inserted, gas permeation is prevented. Since the transparent and liquid impermeable membrane is not joined to the internal flow path material, the flow path material may shift during transport and storage, or wrinkles may occur inside, and also a gas permeable and liquid impermeable film. There is a problem that wrinkles easily occur.

Further, when it is used as a degassing membrane, a channel material is required not only inside the membrane but also outside the membrane, but the external channel material has the same problem as the membrane channel material. .

[0006]

DISCLOSURE OF THE INVENTION In view of the problems of the deaerating membrane as described above, the present invention has an integral structure on both sides of a flow path layer made of a fluid flow member such as a non-woven fabric, a woven fabric or a knitted fabric. And a degassing membrane provided with a degassing layer composed of a gas-permeable and liquid-impermeable membrane. That is, before sealing the end portion of the degassing layer, a gas-permeable and liquid-impermeable membrane is integrally provided on both surfaces of the flow path layer, thereby solving the problem at the time of sealing the end portion. . A gas-permeable and liquid-impermeable membrane may be integrally provided on both surfaces of the fluid flow member, and at the same time, the membrane edge may be sealed.

A gap retaining layer made of a gap forming material may be provided outside at least one surface of the deaeration layers on both surfaces. According to the present invention, similarly, the above-mentioned degassing film is formed in a strip shape and the end is closed, the degassed fluid flows through the flow path layer, and the atmosphere outside the degassing layer is A degassing module that is formed to be depressurized, and the degassing film is formed in a band shape and the end portion is closed, and the internal atmosphere of the flow path layer is depressurized to form the degassing layer. There is provided a degassing module configured to allow a fluid to be degassed to flow outside thereof.

The fluid flow member used as the flow path layer in the degassing membrane of the present invention has a continuous space through which the liquid to be degassed or the degassed gas can flow. For example, non-woven fabric, knitted fabric, woven fabric, expandable material, porous sintered body,
Examples thereof include a net formed by extrusion molding of a heat-meltable resin or a plurality of beads. As the non-woven fabric, an ordinary non-woven fabric can be used, but generally, the thickness is 0.05 mm to 5 mm, preferably 0.1 to 0.5 mm, and the basis weight is 0.1 g / m ^{2 to 5} kg / m ² , preferably 5 g / m ²
-100 g / m ² is used. For example, acrylic resin non-woven fabric (as an example, thickness 3mm, basis weight 300g /
m ² ), and a polypropylene resin non-woven fabric (as an example, a thickness of 3 mm and a basis weight of 150 g / m ² ).

As the woven cloth, generally, it is 5 to 5000.
A woven fabric of denier, preferably 100 to 1000 denier, for example, a plain woven fabric of 500 denier acrylic fiber or 200 denier vinyl fiber can be used. As a knitted fabric,
A knitted cloth or net having a thickness of 0.05 to 5 mm, preferably 0.1 to 0.5 mm, and an opening ratio of 30 to 98%, preferably 60 to 90% is used. For example, a polypropylene fiber of 500 denier knitted to 20 × 22 mesh / inch, a net having a stitch of 5 × 5 mm and a thickness of 0.5 mm can be used.

As the foamable material, a foam having continuous pores such as polyurethane foam and polyethylene foam can be used. As the porous sintered body, a porous material obtained by joining and integrating plastic beads using heat or an adhesive, for example, having a diameter of 100 μm
It is possible to use one obtained by sintering polyvinyl alcohol beads having a diameter of about m, or one obtained by sintering polyethylene beads having a diameter of about 300 μm.

As the material, a thermoplastic resin such as polyethylene, polypropylene, polyurethane, polyester, nylon, vinyl chloride or fluororesin can be used. The thickness of the flow path layer can take any value, but is, for example, 50 to 5000 μm, preferably 100 to 500.
It is possible to use a micrometer type. If the thickness is too small, there is a problem that the pressure loss when passing through the fluid becomes large, and if the thickness is too large, the moving distance of the gas molecules to be degassed becomes large and the degassing performance deteriorates.

As the gas permeable and liquid impermeable film used as the degassing layer in the present invention, a gas permeable resin layer (solid layer) or a composite of a polymer porous body and a gas permeable resin is used. What was done can be used. As the gas permeable resin, silicone resin or fluororesin,
Examples thereof include polytetrafluoroethylene (PTFE) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP). In addition, olefin resins such as polyethylene, polypropylene and polymethylpentene can be used.

The physical properties required for the degassing layer are that the permeation amount of the gas to be degassed is large and the permeability of the liquid in which the gas is dissolved is low or not present at all. The gas-permeable resin film can be used alone as a degassing layer in the form of a sheet, but its thickness is usually 3 to 400 μm, preferably 5
˜30 μm. If this thickness is too large, the amount of gas permeation decreases, and the degassing ability becomes insufficient. Therefore, it is preferable that the gas-permeable resin is as thin as possible within the range that satisfies the mechanical strength and durability required.

Next, the gas-permeable resin is impregnated, coated, or laminated on at least one surface of the polymer porous body to obtain a uniform and thin degassing layer, and the gas permeation amount is increased. Can be improved. The polymer resin in the polymer porous body used here is preferably one having heat resistance and corrosion resistance, and is a porous body of polyolefin resin such as polyethylene and polypropylene, polycarbonate, polystyrene, polyvinyl chloride, polyvinylidene chloride. Porous materials such as polyester, polytetrafluoroethylene, polytetrafluoroethylene / hexafluoropropylene copolymer, and fluororesin porous materials such as polyvinyl fluoride and polyvinylidene fluoride can be used. The porous membrane obtained by stretching fluoroethylene has a unique communicating porous structure composed of fibrils called fibrils and nodes called nodules, and is suitable for compounding with gas permeable resin. It is also preferable because it has excellent heat resistance and chemical resistance.

The average pore diameter of the polymer porous body is 0.01 to 1
It is 0 μm, preferably 0.1 to 1 μm. If this pore size is too large, it becomes difficult to form a thin layer, especially when the gas permeable resin is compounded by impregnation. Porosity is 5 to 95%,
Particularly preferred is 80 to 95%. If the porosity is too small, the gas permeation amount of the degassing layer will decrease, and if it is too large, the strength of the porous body will decrease. 5 to 1000 for thickness
The one having a thickness of μm is preferable, and the one having a too small thickness is not sufficient as a substrate for forming a composite with a gas-permeable resin.

As an example of a method of compounding a gas permeable resin with a polymer porous body, when the gas permeable resin is a silicone resin, an uncured silicone resin solution dissolved in an organic solvent such as toluene is used. A method of applying solvent and then performing solvent removal curing may be mentioned. When the gas permeable resin is a fluororesin, a method of applying a solution dissolved in an organic solvent such as alcohol, ketone, ester, amide or hydrocarbon and then removing the solvent can be mentioned.

When the gas permeable resin is a polyurethane resin, a method of mixing two components of a polyol and a polyisocyanate, applying the mixture in a fluid state before the completion of the curing reaction, and then curing by heating is mentioned. Specific methods of coating include a method using a gravure roll, a reverse roll, a doctor roll, a kiss roll, and a dipping method.

It is also possible to form a thin film of the gas permeable resin alone and then laminate this on the porous polymer body. The channel layer and the degassing layer can be integrated with each other by heat fusion or using an adhesive. For example,
Apply a urethane adhesive with a roll that has a gravure pattern on the flow path layer, and a gas permeable resin film on it.
Composite of gas permeable resin with polymer porous body (impregnation and / or
Or, laminated products etc. are roll-pressed. This process is continuously performed on the upper and lower surfaces of the flow path layer. In this case, an adhesive may be applied to the degassing surface such as a gas permeable resin film, and this may be pressure bonded to the flow path layer.

The degassing layers integrated on both sides of the flow path layer do not necessarily have to be made of the same material. For example, a degassing layer made of a nonporous gas permeable resin is provided on one surface of a sheet material. Alternatively, a degassing layer made of a composite film of a porous polymer and a gas permeable resin may be provided on the other surface. Other combinations may be used. FIG. 1 schematically shows the degassing membrane of the present invention. In the figure, 1 is a flow path layer and 2 is a degassing layer.

A gap forming material may be provided on the outer surface of the degassing layer on at least one side of the degassing membrane. This makes it possible to simplify the production of the degassing module, which is performed by stacking the degassing membranes. Here, a net, a knit, a non-woven fabric, a woven fabric, an extrusion bead, or the like can be used as the gap forming material, and polypropylene, polyethylene,
Polyurethane, vinyl chloride, nylon, polyester,
A fluororesin or the like is suitable, but not particularly limited. The gap forming material can be formed by a method such as attaching a net or a bead to the outer surface of the degassing layer, or attaching a net or a knit with an adhesive.

FIG. 2 shows such a degassing membrane. In the figure,
Reference numeral 1 is a flow path layer, 2 is a degassing layer, and 3 is a gap forming material. The degassing membrane of the present invention as described above is usually formed into a strip shape and the ends in the length direction and the width direction are closed to form a degassing element, which is formed by heat fusion or adhesion. Can be performed by joining. In the case of heat fusion, for example, the flow path layer material located in the middle portion of the sheet can be melted using a heat roll under the conditions of a temperature of 195 ° C., a pressure of 3 kg / cm and a speed of 1 m / min.

In the case of constructing a degassing module using such a degassing element, even if the fluid to be degassed flows through the flow path layer and the atmosphere outside the degassing layer is depressurized, or The internal atmosphere may be decompressed and the degassed fluid may flow outside the degassing layer. 3 and 4 show an example of the degassing module.

A degassing film 11 and a corrugated spacer 1 as shown in FIG.
2 are alternately stacked, and both ends of the spacer 12 and the degassing layer 2 of the degassing film 11 in the lengthwise direction are sealed 13 with an adhesive such as an epoxy resin or silicon resin. It is put in the housing body 15 made of vinyl chloride or the like, and both ends in the length direction are sealed to the housing body 15. Therefore, only the flow path layer 1 of the degassing membrane 11 is open at both ends of the degassing membrane 11 and the spacer 12 sealed in the housing body 15 in the longitudinal direction.

At both ends of the housing body 15 in the longitudinal direction, the inlet flange 16a and the outlet flange 1 of the housing are provided.
6b is attached, and liquid inlet 17 is provided on each flange.
a, there is an opening of the liquid outlet 17b. A vacuum port 17c is provided on the side surface of the housing body 15, and a space communicates with the vacuum port 17c to the outside of the degassing layer 2 of each degassing membrane 11.

Therefore, when the liquid to be degassed is introduced from the liquid inlet 17a and the liquid to be degassed is discharged from the liquid outlet 17b, the liquid to be degassed flows through the flow path layer 1 of each degassing membrane 11. . On the other hand, when a vacuum is drawn from the vacuum port 17c, the liquid in the flow path layer 1 is vacuum-sucked from the outside via the degassing layer 2, and the gas dissolved in the liquid is discharged to the outside of the degassing film 11 and then vacuumed. Mouth 1
It can be removed to the outside through 7c.

In the present invention, the structure of the degassing module is designed so that the liquid to be degassed flows outside the degassing membrane and the degassed gas flows through the flow path layer of the degassing membrane. You can also FIG. 5 is similar to FIGS. 3 and 4, but shows the degassing film 11 having the gap forming material 3 as shown in FIG. 2 and omitting the spacer 12. In this mode, it is not necessary to separately provide a spacer, and the product is stabilized and the number of steps is reduced.

FIG. 6 shows another embodiment. A strip-shaped degassing film (three-layer integrated film) 21 of the present invention, which is formed by fusing four sides in a strip shape, is arranged on a long spacer net 22 and wound around a core rod. At this time, both ends are sealed while applying a silicone or epoxy adhesive 23 with a width of 2 to 3 cm. This roll-shaped film is completely stored in a cylindrical housing such as vinyl chloride, and both ends are potted with the same adhesive to a width of about 3 cm, and after curing, about 1 cm from both ends are cut on both sides. As a result, the internal cross section of the three-layer integrated membrane (deaeration membrane) is exposed, and the flow path layer is
Fluid can flow in. After that, similarly to the case described with reference to FIGS. 3 and 4, an inlet flange, an outlet flange, etc. are provided to complete the degassing module. In using this module, the flow path layer is used as a liquid flow path, and the spacer side is used as a vacuum flow path.

[0028]

【Example】

(Example 1) Formation of degassing film Polyester knit with a thickness of 300 μm (weight per unit area: 30 g /
m ² ), a stretched polytetrafluoroethylene film having a thickness of 30 μm and a porosity of 80% was sandwiched between both sides of m ² ), and was laminated by heat bonding through rolls at 250 ° C. Further, the surface of this film was coated with a moisture-curable one-component silicone RTV rubber to form a silicone solid layer having a thickness of 30 μm. In addition, this coating was performed on both sides one by one. The obtained three-layer integrated film has a thickness of 350 μm as a whole.
It had a uniform thickness, was very thick, and was very easy to handle, and no pinholes were found on its surface. (Example 2) The same polyester knit as used in Example 1 was attached to one surface of the three-layer integrated film obtained in Example 1 with a silicone adhesive in a dot shape on the polyester knit to form a three-layer film. It was attached to the integral membrane. When cured at 60 ° C. for 6 hours, a four-layer integrated film having a total thickness of 650 μm was obtained. (Embodiment 3) The four-layer integrated film obtained in Embodiment 2 is made to have a length of 42.
A rectangular (rectangular) shape with a width of 0 mm and a width of 120 mm was fused and cut on all sides with a heat impulse sealer, and a sealed bag was cut into 30 pieces.
0 sheets were produced.

When 300 sheets of the bag-shaped four-layer integrated film 31 were piled up to a height of 200 mm, they were inserted into the vinyl chloride housing 32 as shown in FIG. 7 while being compressed. The entrance of the housing 32 was 120 mm × 120 mm and the length was 420 mm. Both ends of the stacked four-layer integrated film 31 inserted in the housing 32 were potted to a height of 30 mm as shown in FIG. Toray Silicone CY51-034 (100 parts by weight of main agent, 10 parts by weight of curing agent) was used as the potting solution 33 and cured at room temperature for 2 hours. After completely curing both ends in this way, both ends were sliced 10 mm from the end of the housing as shown in FIG.

As shown in FIG. 10, a cap 35 is put on both ends of the housing 32 to form a liquid inlet / outlet port 36. The cap 35 is an O-ring 3 with respect to the housing 32.
7 was used for sealing, and a through bolt 38 was tightened to fix. The degassing performance of the module thus manufactured is shown below. Performance at 25 ° C tap water, flow rate 1000 l / hr, inlet dissolved oxygen concentration (hereinafter referred to as DO) 8.1 ppm, vacuum degree 30 torr, outlet DO 0.7 ppm, pressure loss 0.5 kgf / cm ² . . (Comparative Example) For comparison, a degassing module was produced by the method disclosed in Japanese Utility Model Publication Nos. 7-13427 and 7-9430. See Figures 11-14.

Thickness 80 μm, pore diameter 0.1 μm, porosity 8
40% basis weight on one side of 0% expanded porous PTFE film
A non-woven fabric of polyester / polypropylene mixed woven fabric of g / m ² was laminated by using a heat roll, and a silicone rubber layer having a thickness of 30 μm was formed on this PTFE surface by coating. Two layers are stacked so that the layers face outward, and a polyethylene spacer net (thickness 2.0 mm, basis weight 100 g /
While sandwiching m ² ) 42, the end portion in the lengthwise direction was fused by a heat impulse sealer 43 to produce a continuous long envelope-shaped degassing film 45.

This envelope-shaped degassing film 45 was made to have a width of 80 cm and a length of 9 m, and both ends in the lengthwise direction were also sealed to form a completely sealed bag 46. Holes were made at six side end portions of the membrane 46 in the lengthwise direction, and six polyethylene tubes 47 for vacuum suction were attached by thermal bonding. In this way, the thickness of the degassing film 46 with the tube 47 attached to one side is 0.1.
A polypropylene spacer net having a weight of 5 mm and a basis weight of 10 g / m ² was stacked and wound around the core rod as in the case of FIG. Spiral membrane 4 with rolled-up outer diameter 123mm
6'is housed in a vinyl chloride pipe 48 as shown in FIG. 14, and is covered with a flange 49 to provide a liquid inlet / outlet port 50 on each flange 49. Further, the six vacuum tubes 47 were combined into one using the connector 51, connected to the connector of the flange portion, and the vacuum hose was connected to the outside.

The deaeration performance of this comparative example is shown in the following table together with the deaeration performance of Example 3. table Example 3 Comparative Example Module size (mm) 150 × 150 × 460 φ130 × 1000L Membrane area (m ² ) 26 13 Membrane packing efficiency (m ² / l) 2.51 1.03 ^* Outlet water DO (ppm) 0. 7 1.3 ^* Pressure loss (kgf / cm ² ) 0.5 0.1 Note) * 25 ° C tap water, 1000 l / hr, inlet DO 8.1ppm, vacuum degree 30 torr As shown in the table above, conventional type of comparative example In comparison with the above, the product of the present invention was a compact module having about 1/2 the size and excellent in degassing performance.

[0034]

According to the degassing membrane of the present invention, a degassing module having an excellent degassing efficiency per unit volume can be obtained, and a compact device can be provided as compared with the conventional one. . Further, the work of manufacturing the membrane-type degassing module from the gas-permeable and liquid-impermeable membrane and the flow path layer material can be made simple and easy, and the working time can be shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a degassing membrane of the present invention.

FIG. 2 is a cross-sectional view of another example of the degassing membrane of the present invention.

FIG. 3 is a sectional view of a degassing module.

FIG. 4 is a partially cutaway perspective view of the degassing module.

FIG. 5 is a cross-sectional view of another example of a degassing module.

FIG. 6 shows another method for producing a degassing membrane.

FIG. 7 is a process diagram of a degassing module of Example 3.

FIG. 8 is a process diagram of a degassing module according to a third embodiment.

FIG. 9 is a process drawing of the degassing module of Example 3.

FIG. 10 is a completed schematic cross-sectional view of the degassing module of Example 3.

FIG. 11 is a process drawing of a degassing module of a comparative example.

FIG. 12 is a process drawing of a degassing module of a comparative example.

FIG. 13 is a process diagram of a degassing module of a comparative example.

FIG. 14 is a process diagram of a degassing module of a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flow path layer 2 ... Degassing layer 3 ... Gap forming material 11 ... Degassing membrane 12 ... Spacer 13 ... Seal 15 ... Housing body 16a ... Housing inlet flange 16b ... Housing outlet flange 17a ... Liquid inlet 17b ... Liquid Exit 17c ... Vacuum port

Claims (7)

[Claims] 1. A degassing layer made of a gas-permeable and liquid-impermeable film is integrally provided on both surfaces of a flow path layer made of a fluid-flowing member such as a non-woven fabric, a woven fabric, or a knitted fabric. A degassing membrane characterized by being 2. The gas-permeable, liquid-impermeable membrane comprises:
The degassing membrane according to claim 1, which is formed of a silicone resin. 3. The gas-permeable, liquid-impermeable membrane comprises:
The degassing membrane according to claim 1, which is a composite of a polymeric porous body and a silicone resin. 4. The degassing membrane according to claim 3, wherein the polymer porous body is porous polytetrafluoroethylene. 5. The degassing film according to claim 1, wherein a gap holding layer made of a gap forming material is provided on at least one outer surface of the degassing layer provided on both surfaces of the flow path layer. 6. The degassing membrane according to claim 1, which is composed of a flow path layer and a degassing layer, is formed into a band shape and has closed ends, and the degassed fluid flows through the flow path layer. The degassing module is formed so that the atmosphere outside the degassing layer is depressurized. 7. The degassing film according to claim 1, which is composed of a flow path layer and a degassing layer, is formed into a band shape and has closed ends, and the internal atmosphere of the flow path layer is decompressed, A degassing module, wherein the degassed fluid is formed so as to flow outside the degassing layer.