JP6195160B2 - Filter elements for high viscosity polymers - Google Patents

Description

  The present invention relates to a filter element suitable for filtration treatment for high viscosity polymers.

  Conventionally, a leaf filter using a metal filter medium has been used in the filtration processing of a high viscosity fluid such as a molten polymer. For example, a support coarse mesh between two plate-like sintered filter media configured in a disk shape. There are some which are integrated with each other via a retainer. The leaf filter is stacked and accommodated in a predetermined housing container in multiple stages, for example, thereby increasing the filtration area per unit volume and constituting a large-capacity filtration device.

  That is, in the configuration, the fluid to be treated is supplied from the upstream primary side (for example, the outer peripheral side of the filter element), and is obtained by removing fine foreign substances contained in the polymer by treating the fluid with the filter medium. The cleaned fluid is collected in the center pole from, for example, a hub member provided at the central portion thereof and fed to the next process. (For example, Patent Documents 1 and 2). Moreover, with the structure, the mesh retainer forms a filtration chamber having a predetermined volume between the upper and lower filter media, thereby providing a smooth flow of the processing fluid.

  Patent Document 3 discloses a retainer used for such a leaf filter, which is formed by a chemical etching process of a metal plate, and a row of a plurality of adjacent through holes in the circumferential direction is formed in a plurality of annular rows concentrically. This shows that a metal support member in which two etching disks are overlapped and joined is used, and the retainer is disclosed as directly supporting the filter medium. (Patent Document 3)

  Japanese Utility Model Publication No. 6-29612   JP 59-120220 A   JP 2009-279517 A

Problems to be disclosed by the invention

  However, the filter elements according to the former Patent Documents 1 and 2 use a mesh retainer made of a coarse mesh as a constituent member, and the woven wire material constituting the mesh is arranged in a direction that impedes the flow of the fluid to be processed, or the pressure It has been pointed out that this leads to increased losses.

  Further, Patent Document 3 is an excellent retainer for improving this and providing a filter product with excellent efficiency. However, in the filter element disclosed in Patent Document 3, a filter filter medium is directly applied to the retainer. This is intended to reduce the size of the entire apparatus.

  However, in that case, if the fluid to be treated is a high-viscosity fluid such as a molten polymer such as polyethylene or polypropylene, it is necessary to apply a high filtration pressure, usually exceeding 2 MPa, to the filter medium. The retainer may be extremely bent and deformed by the through-hole or the edge portion of the retainer, resulting in the worst damage. Therefore, it is necessary to improve the problem that the purity of the polymer is lowered and the quality of the resulting resin molded product is seriously affected.

  Further, as a means for improving this, it is conceivable to interpose a conventionally used metal porous plate, but the contact with the retainer in contact with the normal porous plate becomes a contact between the planes, There is a problem in that the molten polymer remains in the gap between the contact surfaces, causing segregation. This segregation is also a cause of greatly reducing the quality of the resin molded product obtained in the same manner as described above, and corresponds to an important defect factor in the filtration operation.

  An object of the present invention is to provide a filter element suitable for obtaining a higher quality polymer material in the filtration treatment of a highly viscous molten polymer on the premise of employing such an etching retainer.

Means for solving the problem

That is, the invention of claim 1 of the present application uses a filter medium for filtering a high-viscosity polymer and a metal porous plate supporting the downstream surface as a laminated member. A metal filter element provided with a metal retainer for forming
The retainer connects the through-hole rows by a half-etching process and a through-hole row in which a plurality of vertically elongated through-holes extending in the circumferential direction are formed adjacent to each other in the circumferential direction by a full etching process of a metal plate. With the grooved annular part recessed in the side on the alternate surface toward the outer peripheral side, concentrically and in multiple stripes,
The annular portion is provided with a flow path consisting of a stepped portion recessed in one side thereof, alternately on both sides,
The retainer and the perforated plate are filter elements for a high-viscosity polymer, wherein the retainer and / or the perforated plate are in contact with each other at a ridge that bulges toward the contact surface.

Further, the invention according to claim 2 is such that the substantial contact area between the retainer and the perforated plate is set to 30% or less of the apparent contact area by the ridge, In the related invention, each through hole in the through hole row of the retainer is provided with a separation distance of 7 mm or less, and the total aperture ratio is set to 60 to 90%. groove depth t of the groove with the annular portion of the retainer, a filter element of the, wherein the benzalkonium such formed less than half of the total thickness T.

Effect of the invention

  Thus, according to the filter element according to the present invention, the flow of the processing fluid in the element is made smooth by the arrangement of the retainer, resulting in a decrease in pressure loss, and by the high-pressure filtration by interposing the perforated plate. By preventing deformation and breakage of the filter medium and reducing the contact area with the retainer, the occurrence of stagnation in the filtration overtreatment is reduced, and the effect is excellent.

  It is a top view which shows a part of metal filter element in a cross section.   It is sectional drawing which shows the XX 'cross section of FIG.   It is an expanded sectional view which expands and shows the principal part of FIG.   It is a perspective view which shows a part of structure of the retainer of a component.   It is a schematic diagram explaining the contact state of a retainer and a perforated plate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 to 3 show an embodiment of a filter element 1 (hereinafter simply referred to as “element”) according to the present invention. FIG. 1 shows a part of a filter medium 2 forming a surface layer thereof. FIG. 2 is a cross-sectional view showing the XX ′ cross section of FIG. 1. FIG. 3 shows a main part viewed from a cross section different from that of FIG. 2, and shows the structure of the central hub part A and the outer peripheral part B of the right part of the element 1.

  In this form, the element 1 has, for example, a donut-shaped annular shape having an outer diameter of about 30 to 500 mm and a predetermined filter thickness, and is provided with filter media 2 and 2 that exhibit a filtration function on both sides thereof, The filter media 2 and 2 are directly supported by metal porous plates 3 and 3 disposed on the downstream side. Then, the filter medium 2 and the metal porous plate 3 are used as a laminated member 10, the two are arranged on the upper and lower surfaces to face each other, and a metal retainer for forming a filter chamber 11 between the laminated layers. 4 is configured.

  In this embodiment, as shown in FIG. 2, a hub fitting 6 provided with a discharge port 6A for discharging the clean fluid that has been filtered by the filter medium 2 to the next process is provided on the inner peripheral portion A thereof. In addition, the outer peripheral portion B includes a joint portion 5 that joins the laminated members 10 together without leakage by a method such as welding, brazing, or fitting of a rib fitting.

  In the present invention, for example, a filter material 2 made of, for example, a fiber material, a powder material, or a foamed sheet is used in consideration of heat resistance and corrosion resistance of stainless steel, nickel or a nickel alloy, ceramic, and the like. Specifically, fiber materials include woven fabrics, felts, non-woven fabrics, meshes, and sintered bodies obtained by laminating these sheets. In addition to powder sintered bodies made of powder materials, foam structure sheet products, and the like, these may be combined as appropriate. It is constituted by a laminated plate-like porous material that is laminated or composited.

  In addition, the filtration accuracy is arbitrarily set according to the purpose of use of the element 1, the type of the fluid to be processed, and the processing conditions. For example, fine pores of about 0.01 to 100 μm and a thickness of 0.05 to 3 mm Set within the range.

  In particular, the nonwoven fabric sintered body made of stainless steel fibers is not only excellent in corrosion resistance, but also easily welded, pressure-sintered, or machined, and excellent in strength and toughness as compared with the sintered thickness, and is also free of voids. It increases the porosity and is suitable for the present invention. Many such porous sintered filter media have been introduced in known literatures so far, and can be arbitrarily selected.

  Element 1 has annular filter media 2 and 2 thus obtained arranged on the outer surface side, and on the downstream side thereof, metal porous plates 3 and 3 that directly support the filter media 2, and further, between the laminated layers Is provided with a retainer 4 for the filtration chamber 11, and is integrally assembled by seal connection of the outer peripheral connection part 5.

  In FIGS. 1 and 2, spacer metal fittings S in which metal strips are radially arranged are fixed to one side of element 1, and when a plurality of elements 1 are stacked in multiple stages by this spacer S, It is configured to ensure a sufficient flow path. Further, in FIGS. 2 and 3, the hub metal fitting 6 has a discharge port 6A formed radially with a predetermined dimension over the entire circumference thereof, and both of them are joined by a step portion on which the inner edge of the porous plate 3 is placed. In addition, the filter medium 2 is fitted with a rib metal fitting 12 formed by bending a metal strip into a U-shaped cross section on the inner peripheral edge of the filter medium 2.

  Next, the porous plate 3 supporting the filter medium 2 is a porous metal plate (including a sheet) provided with an opening 3A through which the filtered clean fluid is passed, such as a stainless steel porous plate. The opening 3A is formed by, for example, punching, or formed by, for example, drilling or corrosion etching. The shape is an annular shape like the filter medium 2, and the thickness of the structure, the diameter of the opening 3A, and the numerical aperture can be arbitrarily set according to the purpose of use or processing conditions, and are not particularly limited. Absent.

On the other hand, in the present invention, for example, as shown in FIG. 4, the retainer 4 has a plurality of longitudinally extending through holes 4 </ b> A extending in the radial direction and formed on the circumference of the through hole rows 4 a 1, 4 a 2,. The through-hole row 4a is configured to be provided concentrically and in multiple lines via grooved annular portions 4B1, 4B2,. The forming is obtained by a chemical etching process on a predetermined metal plate, and the former through hole 4A is pre-masked so as to completely penetrate between both surfaces thereof, and is fully etched to dissolve and remove a limited portion. The grooved annular portion 4B is similarly subjected to a half-etching process in which only a certain depth is partially dissolved from the one surface side.

  The size and number of the through-holes 4A can be arbitrarily set. For example, a longitudinally elongated opening having a width of about 0.1 to 7 mm and a length of about 1 to 15 mm is preferable. Moreover, the through-hole row | line | column 4a is comprised by arranging the plurality adjacently along the periphery. The distance between the holes 4A in the through-hole row 4a is continuously formed to be, for example, 7 mm or less, preferably about 0.5 to 3 mm. A plurality of the through-hole rows 4a are concentrically arranged via the annular portion 4B. By forming, a disk-shaped retainer 4 is configured.

  More preferably, the opening rate (area ratio of the opening surface) of the through-hole 4A in the retainer 4 is preferably 60 to 90%, for example, and when the separation distance exceeds 7 mm, sufficient flow of the processing fluid is achieved. It is difficult to plan.

The retainer 4 has a structural thickness of about 0.1 to 5 mm, for example, and the size of the retainer 4 is the same as that of the filter medium 2 or, as shown in FIG. In order to ensure, it is possible to use a slightly narrower one so as to remove the outer peripheral portion.
The through-hole 4A is exemplified by a vertically long rectangular shape extending in the radial direction, but is not limited to this, for example, a fan-shaped through-hole opening so as to expand radially from the inner periphery to the outer periphery. As shown in FIG. 1, the through holes can be provided at positions where the through holes are displaced from each other between the through hole rows.

  The annular portions 4B1, 4B2,... Of the retainer 4 are each provided with a concave groove 7 that is recessed on one surface side, and in the present invention, the formation is formed on alternate surfaces toward the outer peripheral side of the retainer 4. It is supposed to be provided. The processing is performed by half-etching of the etching, that is, by processing to a certain depth, and this concave groove 7 functions as a flow passage that circulates through each of the through-holes 4A in the radial direction in contact therewith. For example, FIG. The processing fluid can flow out along the arrow direction.

  Therefore, a smooth flow is provided from the outer peripheral side of the element 1 along the discharge port 6A of the hub fitting 6 on the inner peripheral side. In order to improve the flow, the concave groove 7 has a width of 5 mm or less, for example. As shown in FIG. 4, it is recommended to have a slightly gentle cross-sectional shape, and to form the concave grooves 7 on alternate surfaces toward the outer peripheral side of the retainer 4. The formation depth t of the groove 7 is preferably ½ or less of the total thickness T of the retainer 4 so that sufficient strength as a structural material can be provided.

  Such an etching method has been introduced in various literatures and has been publicly known. For example, after applying a photoresist in advance to a part to be etched to form a film having a predetermined thickness, a solution is sprayed to limit the etching method. It is common to dissolve and remove the formed portion, and the full etching and half etching processes are performed.

The photoresist applied to the stainless steel perforated plate includes, for example, water-soluble casein or PVA having photosensitive characteristics such as ammonium dichromate, and after sensitizing this to form a resist pattern, Furthermore, a ferric chloride solution can be sprayed and dissolved chemically. The treatment temperature is preferably, for example, about 40 to 70 ° C., and other etchants include about 65 ° C. HCL (50 vol%) + HNO ³ (5 vol%) + H ³ PO ⁴ (2.5 vol%). ) And FeCL ³ (34-38 g / L), and those by electrolytic treatment thereof can also be used for the stainless steel. Treatment methods applied to other metal materials are appropriately conditioned and set.

  Next, the porous plate 3 interposed between the filter medium 2 and the retainer 4 will be described in more detail. The porous plate 3 directly supports the filter medium 2 and the through holes 4 a of the retainer 4. It subdivides and functions as a thing which suppresses the deformation | transformation and laceration which the said filter medium 2 curves, for example by the pinching pressure in the edge of the through-hole 4a.

  At that time, for example, a metal sheet such as stainless steel can be formed by punching from one side to provide a plurality of openings 3A of about 0.5 to 5 mm on the entire surface. Further, in the present invention, the surface (lower surface) side in contact with the retainer 4 is swelled to reduce the contact area between the two, and for example, the processing fluid (polymer) is prevented from staying in the minute gap between the two. it can.

  As an example of this contact state, FIG. 5 shows a state in which the perforated plate 3 bulges in a curved surface on the surface in contact with the retainer 4 and contacts at the peak portion. In the same state, for example, such a ridge can be formed on the surface of the retainer 4, and if necessary, both of them can be bulged.

  The bulging shape as shown in FIG. 5 can be formed by, for example, a pinching plasticity phenomenon when the perforated plate is punched out. That is, as a metal plate to be used, for example, a material that is relatively soft and has a relatively large stretch characteristic is selected, and when the press blade is punched by press working, the periphery of the press plate swells as the press blade is inserted. For example, a porous plate 3 having a thickness of about 0.3 to 2 mm is used.

  Further, the peak portion can be formed by, for example, grinding or roller processing without using such punching processing, and further, by providing the peak portion on the contact surface side of the retainer 4, the substantial contact area is reduced. This is preferable.

  Further, FIG. 5 shows the flow of the processing fluid associated with such a contact state by arrows, and the opening of the perforated plate 3 is narrowed down in a drum shape along the thickness cross-sectional direction and widened to open the opening 3A. It is easy to concentrate in the center of Therefore, the substantial contact area is greatly reduced to 30% or less compared to the apparent area drawn by extending the wall surface of the opening 3A of the perforated plate, and the polymer of the fluid to be treated is within the gap. The problem of remaining indefinitely can be prevented.

In addition, the description so far about this filter element 1 is the form which the hub metal fitting 6 is provided in the inner peripheral side A of the element 1 like FIG.1 and FIG.2, and the outer peripheral side B adheres the lamination | stacking member 10 of both front and back. However, the present invention is not limited to this, and includes, for example, the following.
(1) As disclosed in Patent Document 2, the inner peripheral side A and the outer peripheral side B are reversely configured, the inner peripheral side is fixed, and a hub metal fitting is provided on the outer peripheral side B. Including those configured without providing
(2) The filter medium 2, the perforated plate 3 and the retainer 4 may be simply laminated so as to be separable, or may be one obtained by sintering or adhering any or all of the adjacent ones,
(3) Further, the filter medium 2 can employ various forms of filtration materials using fibers and powders made of organic or inorganic constituent materials.

Industrial application fields

  As described above, the filter element of the present invention has adjacent through holes formed by etching as a perforated plate disposed in the middle thereof, and the annular portions provided with multiple steps and alternately provided with the steps. The processing fluid is caused to flow radially toward the central hub portion, and the perforated plate and the retainer are in contact with and supported by the narrow bulging portion, thereby preventing inflow into the gap. In particular, it can be suitably used as a leaf filter for filtration treatment of highly viscous resin materials.

DESCRIPTION OF SYMBOLS 1 Filter element 2 Filter filter medium 3 Perforated plate 4 Retainer 4a Through-hole 4A Through-hole row 4B Annular part 10 Laminated member

Claims (4)

A pair of filter media for filtering high-viscosity polymer and a porous metal plate that supports the downstream surface of the filter medium is used as a laminated member, and a metal retainer is installed to form a filtration chamber between the two facing each other. A metal filter element,
The retainer connects between the through-hole rows by a half-etching process and a through-hole row in which a plurality of vertically elongated through-holes extending in the circumferential direction are formed adjacent to each other in the circumferential direction by a full etching process of a metal plate. With the grooved annular part recessed in the side on the alternate surface toward the outer peripheral side, concentrically and in multiple stripes,
The filter element for a high-viscosity polymer, wherein the retainer and the metal porous plate are in contact with each other at a peak portion where the retainer and / or the porous plate bulges toward the contact surface.     The filter element according to claim 1, wherein a substantial contact area between the retainer and the perforated plate is set to 30% or less of an apparent contact area by the ridges.     The filter element according to claim 2, wherein the through holes in the through hole row of the retainer are provided with a separation distance of 7 mm or less, and the total aperture ratio is set to 60 to 90%.       4. The filter element according to claim 2, wherein a groove depth t of the grooved annular portion is formed to be ½ or less of a total thickness T thereof.

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