JPH0611079Y2 - Microfiltration filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention removes fine particles in highly corrosive fluids or highly reactive fluids used in processes such as semiconductor industry, electronic industry, and chemical industry. The present invention relates to a microfiltration filter for.

(Prior Art and Problems Thereof) Filtration modules in the field of microfiltration are classified into hollow fiber type, coil type, pleated type and laminated type. In either case, the filter element is of a cartridge type, and the function as a filter is exerted by being integrated with a housing that houses the element. The material of this housing is generally roughly divided into metal and synthetic resin, but is selected according to various conditions such as the type of fluid, activity, temperature and pressure.

Filters used in processes such as the semiconductor industry in recent years, particularly filters in the field of precision filtration, require surface smoothness of fluid passages, and particularly in the semiconductor industry, strictness is imposed, and all piping systems are reviewed. Under these circumstances,
Prevention of particulate generation from the filter element and surface roughness of the inner surface of the housing are important matters in the microfiltration filter.

By the way, the fluid introduced from the inlet portion 21a of the housing 21 is filtered by the filter element 22 provided therein, and taken out as a clean fluid from the housing outlet portion 21b. At this time, the downstream side 22b of the filter element 22 always has a structure that is reliably sealed with an O-ring 23 (see FIGS. 4 to 7), a flat packing, an adhesive agent, etc., so that it is contaminated with non-clean fluid. It will communicate with the housing outlet part 21b without being blocked. On the other hand, the upstream side 22a of the filter element 22 does not need to be as described above, and whether the upstream side 22a of the filter element 22 and the inner surface of the housing 21 are provided in a non-contact state (see FIG. 4), or In order to maintain the above-described sealed structure on the downstream side 22b, a cushioning material 24 (see FIG. 5) such as rubber or spring is provided, or, as shown in FIGS. 6A and 6B, the housing inlet portion 21a is provided. Protrusions 25 or ridges 26 are provided in the vicinity, and the protrusions 25 or ridges 26 and a part of the upstream side 22a of the filter element 22 are brought into contact with and supported, and the ridges 26 have slits 26a. Has been processed.

However, as shown in FIG. 4, when the inner surface of the housing 21 and the upstream side 22a of the filter element 22 are not in contact with each other, the upstream side 22a sealing mechanism is damaged and the seal is damaged due to an impact during transportation in the product form. There is a possibility that the O-ring mounting portion having a function may be detached, and finally the function as a filter may not be exhibited. Further, there is a problem that the O-ring mounting portion may be detached from the back pressure.

Further, as shown in FIG. 5, a cushioning material 24 such as rubber or spring is used.
When the filter element 22 is held by interposing the filter element 22 between the upstream side 22a of the filter element 22 and the inlet portion 21a of the housing 21, the number of parts increases as well as the drawback in FIG. 4 is solved. In the case of a highly active fluid such as a halogenated organic solvent, a strong acid or a strong alkali, it is necessary to select the material of the buffer material 24, resulting in a problem of cost increase.

Further, referring to FIGS. 6A and 6B, the housing 21
If the material is a synthetic resin, the protrusions 25 and the protrusions 26 can be easily formed by injection molding, but if the housing is a metal such as stainless steel, as shown in FIG. Since burrs are unavoidable because mechanical processing such as drilling is required, there is a problem that the deburring process is extremely difficult and the cost is increased. In particular, this is an extremely important problem in the fields of the food industry, the chemical industry, etc., as well as the semiconductor industry, the electronics industry, where smoothness of the inner surface of the housing is required. Furthermore, the scattering of the metal pieces by the highly corrosive fluid may also pass through the filter media.

Further, as shown in FIG. 7, this type of filter is connected to a pipe through a joint, but a joint cylinder portion 27 for joint connection is inserted into the inlet / outlet portions 21a and 21b of the housing 21,
The inner surface of the housing 21 and the tubular joint portion 27 are welded and fixed a
Therefore, as in the case of FIG. 6, there are serious problems such as occurrence of burrs inside the housing 21 and a violation of maintaining the inner surface smoothness.

The present invention was developed in view of the above-mentioned conventional problems, and has a function of holding a filter element, improves safety against back pressure, and can be mass-produced at low cost. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention forms a projecting tubular portion by projecting a connecting tubular portion provided in the upper and lower housings to the inside of the housing. An annular recess projecting outward is provided at the position of the upper and lower housings surrounding the projecting tubular part, and a projecting part having a flow path is provided at the upstream side position of the filter member housed in the housing. The distal end portion of the above is inserted into the above-mentioned projecting tubular portion, and the outlet tubular portion provided at the downstream side position of the filter member is attached to the above annular recessed portion through the O-ring.

Further, the connecting cylinder is inserted into the insertion opening formed at the center of the annular recess of the upper and lower housings, and the connecting cylinder and the annular recess are welded and fixed to each other from the outer surface of the upper and lower housings. , A flat plate-like porous thin film laminated filter element, the material of the parts constituting this filter element is a fluororesin or a fluororesin copolymer, and the flat plate-like porous thin film has a pore diameter of 0.01 to 5 μm and an opening ratio.
20% or more and a fluororesin or fluororesin copolymer having a thickness of 50 to 200 μm.

(Operation) In the present invention, the connecting cylinder portion provided in the upper and lower housings is protruded to the inside of the housing to form the protruding cylinder portion, and the protruding cylinder portion is surrounded by the upper and lower housings. A protruding portion having a flow path is provided at an upstream side position of the filter member housed in the housing, and a tip portion of the protruding portion is inserted into the protruding cylindrical portion, and Since the outlet cylinder portion provided at the downstream side position of the filter member is attached to the annular concave portion through the O-ring,
The non-clean fluid that has flowed in from the connecting cylinder portion on the inlet side of the housing passes through the flow path of the projection portion at the upstream side position of the filter member and diffuses in the space on the upstream side of the filter media. Those that have passed through the filter media due to the primary pressure exceeding the membrane resistance are collected as a clean fluid in the outlet tubular portion on the downstream side of the filter member and are integrated in the connecting tubular portion on the downstream side of the housing.
In this case, since the outlet cylinder is attached to the annular recess via the O-ring, the clean fluid and the non-clean fluid have a completely sealed structure and exhibit a sealing function.

(Embodiment) FIGS. 1 to 3 show an embodiment of a microfiltration filter according to the present invention. FIG. 1 is a front view of the microfiltration filter, and FIG. 2 is a vertical sectional view of FIG. FIG. 3 and FIG. 3 are partial enlarged perspective views of the filter element as viewed from the upstream side.

Insertion ports 1a, 2 of the upper housing 1 and the lower housing 2
a, and the step portions 3a and 4a of the connection tubular portions 3 and 4 are engaged with the insertion openings 1a and 2a to connect the outer surfaces of the housings 1 and 2 and the step portions of the connection tubular portions 3 and 4, respectively. The parts 3a and 4a are welded X. The connecting tube portions 3 and 4 are provided so as to project into the inside of the housings 1 and 2 to form protruding tube portions 5 and 6. The upper and lower housings 1 and 2 surrounding the protruding cylinders 5 and 6 are provided with annular recesses 7 and 8 which are concentrically projected outwardly from the protruding cylinders 5 and 6, respectively. Further, the fastening portions 3b,
4b and male screw portions 3c and 4c for connecting the joint are provided.

Filter member 9 housed in the upper and lower housings 1 and 2
In this example, a flat plate-like porous thin film laminated filter element is used.

Explaining this filter element according to FIG. 2, a large number of flow paths 10a are formed in a disc-shaped support plate 10,
The front and back surfaces of the support plate 10 are covered with a flat plate-shaped porous thin film 11, the support plate 10 and a ring-shaped coupling 12 are sequentially laminated, and a central channel 1 provided in the center of the coupling 12 is provided.
2a and the flow channel 10a are communicated with each other, and further, the central flow channel 12a and the outlet tube portion 16 are communicated with each other. The holding plate 13 at the upstream side position of the filter member 9 is provided with a protrusion 15 having a flow path 14, and an insertion step 16 formed at the tip of the protrusion 15 is inserted into the above-mentioned protruding cylinder portion 6, In addition, the outlet tube portion 18 provided on the holding plate 17 at the downstream side position of the filter member 9 is connected to the annular recess 7 via the O-ring 19.
Then, the projecting tubular portion 6 is fitted into the outlet tubular portion 18 and hermetically sealed.

The above-described upper and lower housings 1 and 2 have exactly the same structure, and the filter member 9 is internally provided by butt-welding the both. This filter member 9
The material of all the parts constituting the is a fluororesin or a fluororesin copolymer, and the flat plate-shaped porous thin film 11 has a pore diameter of 0.
It is a fluororesin or fluororesin copolymer having a pore size of 01 to 5 µ, a porosity of 20% or more, and a thickness of 50 to 200 µ. For the flat plate-like porous thin film 11, a polymer such as cellulose acetate, nitrocellulose, polyamide, polyvinyl chloride, polyvinyl alcohol, polymethylmethacrylate, polysulfone, or polyethersulfone is appropriately selected and used. In this case, the other element constituent parts are not limited to the fluororesin or the fluororesin copolymer, and an appropriate material is arbitrarily selected.

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

The non-clean fluid that has flowed in from the connection tubular portion 4 on the inlet side of the lower housing 2 passes through the flow path 14 of the protrusion 15 at the upstream side position of the filter element and diffuses in the space on the upstream side of the filter media. Those that have passed through the filter media by the primary pressure exceeding the membrane resistance are collected as a clean fluid in the outlet tubular portion 18 on the downstream side of the filter member 9, and are collected on the outlet side of the connecting tubular portion 3 on the downstream side of the housing 1, A clean fluid can be obtained efficiently. In this case, the outlet cylinder 18
Since it is attached to the annular concave portion 7 via the ring 19 and the protruding tubular portion 6 is fitted to the outlet tubular portion 18, the clean fluid and the non-clean fluid have a completely sealed structure, and the filter by heat cycle is used. O-ring 19 due to element contraction
Since leakage from the can also be prevented, the sealing function can be reliably exerted, and the fluid can be precisely filtered with high precision.

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

That is, the filter element mounted in the housing is securely held, and the sealing function on the downstream side of the filter element is effectively exerted, so that the durability as a filter is good, and compared with the conventional filter. In addition, the safety against back pressure can be remarkably enhanced, and further, the present invention can be mass-produced at low cost and has an excellent economical effect.

[Brief description of drawings]

1 to 3 show an embodiment of a microfiltration filter according to the present invention. FIG. 1 is a front view of the microfiltration filter, FIG. 2 is a longitudinal sectional view of FIG. FIG. 4 is a partially enlarged perspective view of the filter element as seen from the upstream side. FIGS. 4 to 6 are vertical sectional views showing respective conventional examples, and FIG. 7 is a sectional view showing one of conventional housings. Is. 1, 2 ...... upper and lower housings 3, 4 ...... connection cylinders 5, 6 ...... protruding cylinders, 7, 8 ...... annular recesses, 9 ...... filter members, 14 ...... flow paths, 15 ...... Protrusion, 16 ... Insertion step, 18 ... Exit tube, 19 ... O-ring.

Claims (5)

[Scope of utility model registration request] 1. A connecting tubular portion provided on the upper and lower housings is projected into the inside of the housing to form a protruding tubular portion, and the protruding tubular portion is projected outward at a position of the upper and lower housings surrounding the protruding tubular portion. In addition to providing the annular recessed portion, a protrusion having a flow path is provided at a position upstream of the filter member housed in the housing, and the tip portion of the protrusion is inserted into the protruding cylindrical portion, and the filter is provided. A microfiltration filter, characterized in that an outlet cylinder provided at a position downstream of the member is mounted in the annular recess via an O-ring. 2. A utility model in which a connecting cylinder is inserted into an insertion opening formed at the center of an annular recess of the upper and lower housings, and the connecting cylinder and the annular recess are welded and fixed to each other from the outer surface of the upper and lower housings. The microfiltration filter according to claim 1. 3. The microfiltration filter according to claim 1 or 2, wherein the filter member is a flat plate-shaped porous thin film laminated filter element. 4. The microfiltration filter according to claim 3, wherein the material of the parts constituting the filter element is a fluororesin or a fluororesin copolymer. 5. The utility model registration according to claim 3, wherein the flat plate-like porous thin film is a fluororesin or fluororesin copolymer having a pore size of 0.01 to 5 μm, a porosity of 20% or more and a thickness of 50 to 200 μm. Microfiltration filter.