JPH0671535B2 - Flat thin film laminated filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flat-plate thin-film laminated filter for separating microorganisms or fine particles from a liquid or gaseous raw fluid by using a porous thin film, In particular, the present invention relates to a flat-plate thin-film laminated filter having a special structure in which a porous thin film having innumerable continuous pores having a maximum pore diameter of 0.01 to 10 μm is utilized and the porous thin films are alternately laminated together with a support, a spacer and the like.

(Prior Art) Since the flat plate-like porous thin film has a high open area ratio of 60 to 80% and its mechanical strength is extremely weak, when it is used as a filter, it is usually supported on a support without bending the flat plate. It is placed at the same time and is sealed with a gasket.

However, if it is necessary to process a large amount of fluid in the semiconductor industry, pharmaceutical industry, etc., if the flat plate membrane is used as it is, the filter housing will become huge, and the risk of damage due to bending of the flat plate membrane will be increased. So-called pleated-type cartridge filters have been proposed with commercialization in mind.

Under the above circumstances, a so-called disposable type filter element has been recently developed, which has a structure in which a large number of small flat plate membranes are laminated together with a support or a spacer to avoid bending of the flat plate membranes. This type of filter also has drawbacks.

That is, the disposable type filter has a complicated structure,
The assembly process is difficult, and moreover, not only does it require a sealing structure to seal the membrane, but it is also a disposable product.
It is an unavoidable problem that the cost is inevitably increased as compared with the case where the above-mentioned flat plate membrane is used as it is or the case where an ordinary pleat cartridge filter is used.

Therefore, conventionally, the following improved structure has been proposed as a disposable type laminated filter.

For example, JP-A-56-129016 or JP-A-59-102111.
It is disclosed in the publication.

As for the former, as shown in FIGS. 11A and 11B and FIGS. 12A to 12C, the whole is immersed in a solvent on the upper and lower surfaces of the support 1 or the support 6 having a large number of ribs 1a formed by injection molding. The porous thin film 2 is adhered and laminated to form a laminated structure, and the protective plate 4 having the outflow portion 3 on the upper portion and the protective plate 5 on the lower portion are provided. Thin film
Porous thin films 2a and 2b having different shapes are bonded to the upper and lower surfaces of the support 1. The support 6 shown in FIG. 12 is a combination of an upper plate 6a and a lower plate 6b having different shapes.

In the latter, as shown in the same publication, a plurality of support plates are laminated at appropriate intervals, both sides of each support plate are covered with a porous thin film, and a spacer is provided between the laminations on the side of the raw fluid flow passage. At the same time, it adopts a bellows-like structure in which porous thin films are sealed at the outer and inner circumferences.

(Problems to be Solved by the Invention) However, according to the above-mentioned conventional example, there are the following problems.

That is, the former is a porous thin film 2a and a porous thin film having a shape different from that of the porous thin film 2a due to the structure for taking out a clean fluid from between the films.
2b is required, or in another form, the support 6 is a combination of the upper plate 6a and the lower plate 6b having different shapes, which increases the component cost or the assembly cost. Further, since the entire porous thin film 2 is immersed in the solvent, it causes unnecessary invasion to the porous thin film 2 or the supports 1 and 6 and is affected by the residual solvent. Is fixed to the ribs 1a on the supports 1 and 6, there is a problem that there is a substantial loss of the film area.

The latter has a bellows-like structure in which both sides of each support plate are covered with a porous thin film, spacers are provided between the stacks on the side of the raw fluid flow passage, and the porous thin films are sealed at the outer peripheral portion and the inner peripheral portion. Therefore, even if the outer or inner circumference is sealed first, as long as the membranes are sealed together, it is physically unnatural and difficult to seal the latter. Therefore, it cannot be said that the sealing property is extremely uncertain and the assembly method is complicated, which is a means contradictory to the cost reduction.

The present invention was developed in order to solve the above-mentioned conventional problems, and provides a disposable type flat-plate thin-film laminated filter having all the conditions such as reliability of sealing as well as component cost and assembly cost. Is intended.

(Means for Solving the Problems) In order to achieve the above object, the present invention encloses a support in a plate-like porous thin film made of a thermoplastic synthetic resin, and interposes this porous thin film with a spacer. Then, in a flat-plate thin-film laminated filter in which a plurality of layers are laminated, the above-mentioned support is included and two porous thin films having the same shape are superposed, and the porous thin film except for the vicinity of the clean fluid extraction opening is formed. Form a filter unit by sealing the peripheral parts of the conductive thin film.
On the outer surface near the opening of each porous thin film, the surface of the synthetic resin gasket is dipped with a solvent that does not dissolve the porous thin film. Of the filter unit and the gasket are liquid-tightly sealed by inserting the spacer into the continuous through hole, and the spacer is interposed between the filter units to form a laminated body by fitting the opening of the spacer to the outer peripheral surface of the gasket. I did it.

(Operation) Therefore, according to the present invention, the two porous thin films having the same shape are superposed on each other and the support is contained therein. Therefore, the porous thin film is reliably held against the filtration pressure, and the clean fluid A flow path is formed. Moreover, because the filter unit is formed by welding the peripheral portions of the porous thin film except for the vicinity of the clean fluid extraction opening of the porous thin film, not only the assembly is easy, but also the permanent sealing function is provided. Also, since a large number of filter units are laminated with a spacer interposed, the flow path of the original fluid can be effectively secured, and the reverse pressure from the clean fluid side can be reliably resisted. Further, on the outer surface near the opening of each porous thin film, the surface of the synthetic resin gasket is dipped and dissolved in a solvent that does not dissolve the porous thin film. Since the filter unit and the gasket are liquid-tightly sealed by entering the innumerable continuous through-holes, the assembling process is simplified and the sealing function is reliable. Mixing with a fluid (undiluted solution, contaminated gas) can be avoided, and microorganisms and fine particles in a liquid or gas fluid can be separated and discharged from an outlet.

(Embodiment) FIGS. 1 to 4 show an embodiment of a flat-plate thin film laminated filter according to the present invention. FIG. 1 is a sectional view of a full filtration type, and FIG. 2 is a cross-flow type. A sectional view, FIG. 3 is a sectional view showing another example of the full filtration type, and FIG. 4 is a sectional view showing another example of the cross flow type.

In the drawing, 11 is a flat plate-like porous thin film having a number of continuous pores with a maximum pore size of about 0.01 to 10 μm, and the porous thin film 11 in this example has a circular shape, and further, FIG. In all filtration type), a clean fluid (filtrate) extraction opening 11a is opened in the center, and in FIG. 2 (cross flow type), two clean fluid extraction openings 11b, 11c and a central opening are provided on the left and right planes. Form 11d. Two identically shaped porous thin films 1
A circular sheet-shaped support 12 is included in the layers 1 and 11 and overlapped with each other, and the clean fluid extraction openings 11a to 1 of the porous thin film 11 are stacked.
Peripheral edges 11e, 11f of the porous thin film 11 except for the vicinity of 1c
Are welded and sealed by means such as a hot press to form a filter unit 13. Multiple filter units 13
Is a spacer 1 having an opening 14a and having a rib surface.
4, and the ring-shaped gasket 15 provided integrally with or separately from the spacer 14 and the porous thin film 11 is adhered to the outer surface in the vicinity of the clean fluid extraction opening with a small amount of solvent. Then, the laminated body 16 is formed.

The above-mentioned support 12 or spacer 14 is a mesh, non-woven fabric, woven fabric, or other porous body formed by a continuous processing method that is more productive than injection molding, or has uniform unevenness on the surface formed by extrusion molding or the like. It can be easily obtained by selecting a sheet plate or the like having, and punching out a relatively inexpensive material.

Further, the spacer 14 is provided with the gasket 15 integrally or separately, but in the present example, the gasket 15 is provided as a separate body fitted in the opening of the spacer 14. The outer surface of the porous thin film 11 in the vicinity of the clean fluid extraction opening is welded with a solvent to ensure the sealing, but when the synthetic resin materials are usually adhered to each other by a solvent, the mutual Materials that are compatible with each other are selected, and solvents that dissolve each other are used, but this principle is not applied to the solvent adhesion of the porous thin film 11 in this embodiment.

That is, the porous thin film 11 is not dissolved, but using a solvent that dissolves the target synthetic resin gasket 15, the surface of the gasket 15 is dissolved, and then the porous thin film 11 is pressed, the surface of the gasket 15 The melted resin is a porous thin film
It enters 11 innumerable continuous holes and is securely adhesively sealed.
Further, if a solvent having a boiling point as low as possible is used, there is almost no problem of toxicity due to residual solvent and deterioration of members with time, and substantially the same effect as thermal welding can be obtained. When enumerated as a specific combination, for example, in the case of a porous thin film of cellulose acetate, the gasket may be polysulfone or polycarbonate, and trichlorethylene may be used as the solvent. By using a porous thin film having relatively high solvent resistance such as polyamide, polypropylene, polyethylene, and fluororesin, a wide range of solvents and gasket materials can be selected.

Further, protective members 17 and 18 having ribs on the inner surfaces are provided at both ends of the laminated body 16 in the laminating direction, and a raw fluid inlet 19 and a clean fluid outlet 20 are provided on one or both of the protective members. FIG. 1 shows an example in which the protective member 17 is provided with a clean fluid outlet 20, and FIG. 2 is an example in which the protective member 17 is provided with a raw fluid inlet 19 and clean fluid outlets 20, 20.

Further, as shown in FIG. 3, a support cylinder 21 having a communication hole 21a is provided in the clean fluid extraction opening 16a formed in the laminate 16, and the support cylinders 21 are provided at both ends of the laminate 16 in the laminating direction. It adheres to the protective members 17 and 18 to exert the reinforcing function of the laminated body 16.

The support cylinder 22 shown in FIG.
The support cylinder 22 is formed with a combination of a and the protruding cylindrical portion 24a of the protection member 24, and the communication hole 22a is formed in the support cylinder 22.

The laminated body 16 and protective members provided at both ends of the laminated body 16 in the laminating direction are housed in the upper and lower housings 25 and 26, and a filter 27 is provided.
Are configured. Specifically, in the ninth figure, the outlet 25a of the upper housing 25 and the outlet 20 of the protective member 17 are turned off.
The lower housing 26 and the upper housing 25, which are assembled via a ring 30 and have an inflow portion 26a and a protrusion 26b, are provided with a filter 27.
Assemble.

Next, the operation of the above embodiment will be described.

Supports by stacking two identically shaped porous thin films 11, 11.
Since 12 is included, the porous thin film 11 is reliably held against the filtration pressure, and a filtration flow path is formed, and the porous thin film 11 except for the vicinity of the clean fluid extraction opening 11a. Since the filter unit 13 is formed by welding the peripheral portions 11e and 11f of the porous thin films 11 and 11 to each other, not only is it easily assembled, but also a permanent sealing function is exhibited, and a large number of filter units 13 are installed. Since the spacers 14 are laminated with the spacers 14 interposed therebetween, the passage of the original fluid is effectively secured, and the back pressure from the clean fluid side can be reliably counteracted. Further, since the gasket 15 provided integrally with the spacer 14 or provided separately is welded to the outer surface of the porous thin film 11 in the vicinity of the clean fluid extraction opening with a solvent to form the laminated body 16, the assembly process is simplified. As well as
Mixing of the clean fluid and the raw fluid can be avoided, and microorganisms and fine particles in the liquid or gaseous raw fluid can be reliably separated and discharged from the outlet.

Next, FIGS. 5 to 8 are sectional views showing various aspects of another embodiment of the present invention.

The same parts as those of the present embodiment and the above-mentioned embodiments are designated by the same reference numerals and the description thereof will be omitted.

In the drawing, a support 12 is included in a flat plate-like porous thin film 11 made of a thermoplastic synthetic resin, and the porous thin film 11 is laminated with a spacer 14 interposed to form a laminate 16, and the laminate 16 is formed. The protection members 17 and 18 are provided at both ends in the stacking direction of 16, and a filtration cylinder 28 having a pre-filter function of the porous thin film 11 provided on the protection member is provided at the outer peripheral position in the horizontal direction of the stack 16 for filtration. The cylindrical body 28 forms a large number of openings 28a. By providing the filter member 29 on the outer periphery of the filter cylinder 28, the pre-filter function of the porous thin film 11 is increased.

When the above-mentioned laminated body 16 and the protective members 17 and 18 provided at both ends in the laminating direction of the laminated body 16 are housed in the upper and lower housings,
A product similar to the filter in FIG. 9 can be manufactured.

(Effects of the Invention) As is clear from the above, according to the present invention, there are the following excellent effects.

In other words, it has become possible to provide a disposable flat-plate thin-film laminated filter that satisfies all the conditions such as the reliability of sealing as well as the cost of parts and assembly.

Specifically, as a sealing means for avoiding the mixing of the clean fluid and the raw fluid, by heat-welding the membranes and adhering the gasket and the porous thin film with a small amount of solvent, a safe and reliable sealing is achieved. Sex can be done easily.

Further, as compared with the conventional sealing means, it is not necessary to immerse the entire porous thin film in a solvent, and a necessary minimum amount of solvent may be used, so that various problems due to the residual solvent are significantly reduced and excessive Invasion of the support and the porous thin film by the solvent is minimized, and in particular, the problems of the hydrophilic agent in the porous thin film and the outflow of various resin additives can be solved at once.

Furthermore, since the support and the spacer are continuously molded without using injection molding, it is possible to reduce the thickness, reduce the overall thickness of the laminated body, and make it compact as a whole. effective.

[Brief description of drawings]

1 to 4 show an embodiment of a flat-plate thin film laminated filter according to the present invention. FIG. 1 is a sectional view of a full filtration type, FIG. 2 is a sectional view of a cross flow type, and FIG. 3 is a cross-sectional view showing another example of the full filtration type, FIG. 4 is a cross-sectional view showing another example of the cross-flow type, and FIGS. 5 to 8 show respective aspects of other embodiments of the present invention. The sectional view shown in FIG. 9, FIG. 9 is a sectional view showing an example of the filter in which the flat-plate thin-film laminated filter according to the present invention is housed in the housing, FIG. 10 is a perspective view of the filter unit separated, and FIG. 10B is the same unit. Perspective view of
FIG. 10C is an exploded perspective view of the filter according to the present invention, and includes FIGS. 11A and 11B and FIGS. 12A to 12C.
FIG. 4 is a cross-sectional view showing a part or the whole of a conventional example. 11 ... Porous thin film 11a, 11b, 11c ... Extraction opening 11e, 11f ... Edge 12 ... Support, 13 ... Filter unit 14, 23 ... Spacer 15 ... Gasket, 16 ... Laminate Body 17, 18, 24 …… Protective member 19 …… Original fluid inlet, 20 …… Clean fluid outlet, 21,22…
… Support tube 25 …… Upper housing 26 …… Lower housing, 27 …… Filter

Claims (7)

[Claims] 1. A flat-plate thin-film laminated filter in which a support is included in a flat plate-shaped porous thin film made of a thermoplastic synthetic resin, and a plurality of the porous thin films are laminated with a spacer interposed therebetween. Encapsulate and superimpose two identically shaped porous thin films, and seal the peripheral portions of the porous thin films except for the vicinity of the clean fluid extraction opening of the porous thin film to form a filter unit, On the outer surface near the opening of each porous thin film, the surface of the synthetic resin gasket is dipped with a solvent that does not dissolve the porous thin film. Liquid-tightly seal the filter unit and the gasket by inserting it into the continuous through hole of the spacer, and fit the opening portion of the spacer on the outer peripheral surface of the gasket so that a space is provided between the filter units. Flat film laminated filter, characterized in that to constitute a laminate with intervening. 2. A flat filtration thin film laminated type of full filtration type according to claim 1, wherein protective members are provided at both ends of the laminated body in the laminating direction, and one of the protective members is provided with a clean fluid outlet. filter. 3. A cross-flow type flat plate according to claim 1, wherein protective members are provided at both ends of the laminated body in the laminating direction, and one of the protective members is provided with a raw fluid inlet and a clean fluid outlet. Thin film laminated filter. 4. The flat-plate thin-film multilayer filter according to claim 1, wherein the maximum pore size of the porous thin film is 0.01 to 10 μm. 5. A support cylinder having a communication hole is provided in the raw fluid outlet opening formed in the laminate, and the support cylinder is fixed to protection members provided at both ends of the laminate in the stacking direction. Item 3. A full-filtration type or cross-flow type flat-plate thin-film laminated filter according to items 4 to 4. 6. The support cylinder according to claim 5 is constituted by a combination of a projection cylinder part of each spacer and a projection cylinder part of a protective member, and a communication hole is formed in this support cylinder. Alternatively, a cross-flow flat-plate thin-film laminated filter. 7. The full filtration type according to claim 1, wherein the laminated body and protective members provided at both ends in the laminating direction of the laminated body are housed in upper and lower housings to constitute a filter. Alternatively, a cross-flow flat-plate thin-film laminated filter.