JPH1176721A - Laminated metal filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated metal filter used for filtering high viscosity fluid such as molten polymer and particularly enabling low pressure drop through it. SOLUTION: A laminated metal filter that filter medium made of metal 2 and a supporting member 3 for directly or indirectly supporting the filter medium made of metal 2 are laminated is formed. The supporting member 3 consists of a netlike body that meridians 11 and parallels 12 using metal fine wires are interwoven, and at least one of the meridians 11 and the parallels 12 is formed into a corrugated line in which bent parts 16 of recessed parts 14 and projected parts 15 are repeated, and the corrugated line is interwoven with the other metal fine wires crossing the corrugated line skipping one or more bent parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated metal filter which is suitably used for filtering a high-viscosity fluid such as a molten polymer, and in particular, can reduce pressure loss.

[0002]

2. Description of the Related Art In the field of chemical fibers, the quality of spinning and film formation is improved by removing foreign substances in a molten polymer by a metal filter.

At present, as a filter used in such an application, for example, as a leaf-shaped filter, Japanese Utility Model Publication No.
As proposed in Japanese Patent Application Laid-Open No. 4-980, etc., as illustrated in FIG. 6, a metal filter medium A having a predetermined filtration characteristic and a support member B such as a mesh member that supports directly or indirectly on the downstream side thereof. Are stacked and arranged, and a disk-shaped filter medium integrated by welding the outer periphery of the filter medium A is often used.

[0004] In this case, the supporting member B is a plain weave made of, for example, a thin metal wire of about 0.8 mmφ in order to secure strength for supporting the filtration pressure applied to the filter medium A and an outflow passage through which the filtered molten polymer passes. A relatively coarse mesh such as a mesh is used.

In the conventional filter as well, the filter material A is used to prevent the convex portion C of the mesh member, which is the bent portion of the thin metal wire, from pressing the filter material and locally crushing the pores of the filter material to cause clogging. In some cases, an interposing member D such as a punching plate or a powder sintered body is disposed between the support member B and the support member B.

[0006]

In the case where the fluid to be treated is, for example, a molten polymer of a chemical fiber, which is liable to change with time, the fluid to be treated filtered through the filter medium is smoothly discharged, and the flow resistance is reduced. However, it has been found that it is important to improve the support member and improve the performance.

That is, when the filter medium is directly supported by the mesh, the filter medium is directly supported by the convex portion formed at the intersection of the mesh with the meridian and the latitude line. Crossing requires increasing the number of intersections and reducing the load pressure applied per intersection.

However, such a structure increases the number of wires, and accordingly, the effective passage area occupied in the outflow passage is reduced, so that the outflow of the fluid to be treated is obstructed and sometimes the stagnation occurs. This makes it difficult to obtain a high-quality filtered molten polymer.

In order to increase the number of outflow passages, simply increasing the line spacing to reduce the number of used passages reduces the number of supporting points for supporting the filter medium, and increases the contact pressure with the filter medium. The filter holes are clogged, and sometimes the filter medium itself cannot withstand the filtration pressure, resulting in deformation and breakage.

[0010] Further, such a conventional supporting member is manufactured by mechanical weaving (plain weaving), and processing foreign matter and impurities generated at the time of net forming remain in the intersections and the like, making it difficult to completely remove the foreign matter. There is also a problem that it is exfoliated during the filtration treatment and is mixed with the fluid to be treated, thereby deteriorating the quality.

As other support members other than the net-like body, for example, a corrugated metal flat wire formed into a spiral state (for example, Japanese Utility Model Publication No. 1-148713), and inverted metal flat wires are arranged in the outflow direction and assembled. Thing (for example,
No.-4210) is also known, but such a support member requires labor for assembling, increases the weight and makes it difficult to handle, and in the former support member, the convex portion comes into contact with the filter medium in a flat surface. This increases the chance of stagnation, and is not suitable for filtering a molten polymer or the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laminated metal filter which can solve such a problem on the basis of skipping a bent portion of a corrugated wire and crossing and weaving fine wires.

[0013]

Means for Solving the Problems The invention of claim 1 of the present invention is a laminated metal filter comprising a metal filter medium and a support member for directly or indirectly supporting the filter medium. The support member is a meridian using a fine metal wire, a net-like woven weft, and at least one of the meridian and the weft, a concave portion, using a corrugated line formed in a wavy pattern that repeats a bent portion of a convex portion, Further, the corrugated line is characterized in that one or more of the bent portions are skipped and woven with the other thin metal wire crossing the bent portion.

[0014] This makes it possible to increase the crossing pitch of the fine metal wires, to reduce the number of the fine metal wires, and to reduce the number of the fine metal wires, as compared with a conventional mesh body in which the fine metal wires are crossed at each bent portion. The area of the outflow passage is reduced by reducing the number of meridians, the number of latitude lines, and the number of intersections while maintaining the number of convex portions on one surface of the support portion, that is, the bent portion, and having substantially the same support strength. It increases the flow resistance of the fluid and makes the flow smoother. In addition, since the number of filters used can be substantially reduced, the filter itself is also reduced in weight, and therefore, two opposing characteristics of reducing the outflow resistance of the filtrate and improving the filtration pressure resistance are not sacrificed without sacrificing one of them. According to a second aspect of the present invention, an interposition member made of a punching plate or a metal powder sintered plate is disposed between the metal filter medium and the support member. Thus, due to the filtration pressure, the projections at the intersections of the thin wires of the support member locally press the filter medium, thereby reliably preventing the occurrence of indentations and the like, thereby increasing the support strength and expanding the outflow passage.

The invention according to claim 3 is characterized in that the support member is woven by crimp weaving. At this time, since the corrugated line and the weft line use corrugated lines that have been previously shaped in a wavy form, there is no generation of foreign matter during weaving, there is no biting at intersections, etc., and by washing the corrugated lines in advance Useful for cleaning filters.

[0016]

FIGS. 1 and 2 show an embodiment in which a laminated metal filter 1 of the present invention is used as a leaf filter. The laminated metal filter 1 comprises a hollow disc-shaped filter medium 2, A support member 3 formed of a hollow annular mesh body for supporting the filter medium 2; and an interposition member 4 between the filter medium 2 and the support member 3 for preventing direct contact between the filter medium 2 and the support member 3. Has been arranged. The insertion member 4 is supported by a convex portion of the support member 3 so as to prevent deformation and blockage of the filter hole of the filter medium 2 due to the filtration pressure, that is, to prevent blindness.

Further, the outer peripheral edge of the filter medium 2 and the interposing member 4
The portion beyond the outer peripheral edge of the support member 3 is pressed and the periphery of the pressed portion is welded and joined by melting.
The inner peripheral edge of each filter medium 2 is reinforced by a reinforcing ring 6 having a U-shaped cross section, and an inner ring 9 having a horizontal hole 7 is arranged between the reinforcing rings 6 on both sides. The inner peripheral edge of the insertion member 4 may be welded to the inner ring 9.

Such a laminated metal filter 1 is shown in FIG.
Are arranged in a filter tank (not shown) and stacked through a spacer 10 shown by a one-dot chain line, and a processing liquid, for example, a high-pressure polymer is allowed to flow, so that the liquid to be processed passes through the filter medium 2 and the insertion member 4 and is supported. It flows inside the member 3 and is collected through the lateral hole 7.

The filter medium 2 is preferably a plate-shaped sintered body obtained by randomly entanglement of fine metal fibers such as stainless steel, nickel steel, or the like, having predetermined filtration hole characteristics, and sintering them. As a filter medium 2, a sintered body of a metal powder,
Alternatively, a sintered body of a mixture of a metal powder and a short metal fiber may be employed. Furthermore, depending on the type of the liquid to be treated and the processing conditions, such as a laminate of multiple layers of sintered bodies with different specifications such as filter holes and materials, and a laminate of a fine mesh wire mesh on the surface to protect the filter media surface layer Various settings can be made.

Although a punching plate having a plurality of small holes is used as the insertion member 4, a plate-shaped sintered metal powder having pores larger than the filter medium 2 may be used.

As shown in FIGS. 3 and 4, the support member 3 is made of a mesh formed by weaving a meridian 11 and a weft 12 using a thin metal wire, such as a stainless steel wire or a nickel wire. A heat-resistant metal is preferable, and a round wire or a deformed wire having a thickness of 0.3 to 3.0 mm is used. Note that the specifications of each part of the thin metal wire can be variously changed depending on the use or state to be used. Furthermore, the arrangement pitch P1 of the meridians or latitudes
1, P12 may be the same or different,
Further, it is usually preferable that the number per inch is about 2 to 5 pieces. When the number decreases, it is preferable to increase the thickness and improve the strength of the thin metal wire itself.

As at least one of the meridian 11 and the weft line 12, a crimped crimping line 20 is used which is preliminarily formed into a wave shape in which a bent portion 16 consisting of a concave portion 14 and a convex portion 15 is viewed from one side of a thin metal wire. I have. By using such a corrugated wire 20, it is possible to enhance the shape maintenance as a net-like body, and it is possible to further increase the pitch interval.

When the corrugated wire 20 is used for both the meridian 11 and the weft wire 12, the mesh can be woven by a so-called crimping machine which is assembled by fitting the corrugated wire 20 and the corrugated wire 20 before the fitting. By sufficiently washing, it is possible to prevent foreign matter from remaining on the surface and intersection of each line of foreign matter due to weaving as compared with the conventional machine automatic weaving method of bending and weaving.

The pitch P16 between the bent portions 16 of the corrugated wire 20 formed by the concave portions 14 and the convex portions 15 is preferably as small as possible for the fine metal wire. When it is about 6 to 2.5 mm, it is about 2 to 5 mm. In addition, the uneven pitch of the bent portion can be changed for one thin metal wire, and can also be changed for a meridian and a latitude line. Further, in order to withstand a predetermined filtration pressure, the total amplitude height H is preferably formed to be, for example, about 1.5 to 2.2 times the wire diameter d, and to have an average inclination angle θ of 30 to 80 °. preferable. At this time, the fact that the height H includes the above 2.0 or less is based on the assumption that local cross-sectional deformation due to pressurization at the time of forming the bent portion is performed. The pitch of the bent portion can be changed for one thin metal wire, and can be different for a meridian and a latitude.

The corrugated line 20 is woven with one or more of the bent portions 16 and intersected with the other thin metal wire, in this example, another corrugated line 20a to form a net-like body.

The interval at which the intersecting thin metal wires fly over the bent portion 16 is one or more. In the case of FIG. 3, the two bent portions 16, 16 are skipped between the parallel thin wires. I have. That is, the third bent portion 16 intersects with another next corrugated line 20a at the third bent portion 16, with the bent portion adjacent to one intersection of the corrugated lines being the first. The number of the bent portions 16 to be skipped between the parallel thin wires is usually about 2 to 10, and the cross pitch is such that the holding strength of the support member 3 does not decrease in consideration of the diameter d of the thin metal wire. Note that the dashed-dotted square in FIG.

Further, the number of skipped portions of the bent portion is determined by a meridian,
In addition to the case where the number of latitude lines is the same, the arrangement may be made different in the line direction or the position may be changed. Meridians at intervals,
In the case of using different parallel lines, it is also possible to reduce the number of support points without significantly reducing the number of support points.
This can contribute to weight reduction and flow characteristics.

As described above, since the woven fabric is formed by skipping the bent portions 16, the weight can be reduced, and since the number of bent portions can be formed as compared with the related art, the wire itself has high pressure resistance. ing. Therefore, it is possible to suppress the decrease in the number of the bent portions as a whole, and to reduce the load pressure acting on the bent portions, and there is no insertion member as in the metal laminated filter 1 shown in FIG. Occurrence of indentation on the filter medium can sometimes be reduced.

For this reason, the number of support portions (the number of convex portions) for directly or indirectly supporting the filter medium per unit area of the support member is smaller than that of a conventional mesh body in which each bent portion intersects without being skipped. ) Can be reduced without significantly reducing the number of meridians and parallels and their intersections, while maintaining the same supporting strength, increasing the area of the outflow passage, reducing the flow resistance of the fluid, Be smooth. Further, since the number of used filters can be substantially reduced, the weight of the filter itself can be reduced, and the handling is facilitated.

It should be noted that such a supporting member can be applied to various shapes and types in accordance with various filters such as a plate shape and a cylindrical shape in addition to the leaf shape.

[Specific Example] A filter medium 2 as shown in FIG.
A laminated metal filter having a support member 3 and an interposition member 4 is formed by using a sintered body obtained by randomly entangled and sintering fine stainless steel metal fibers as a filter medium 2, and using a punching plate as the interposition member 4. Made. The support member 3 was woven by a crimp molding machine using corrugated wires made of stainless steel having a diameter of 2 mm as the meridian 11 and the weft 12.

The corrugated line 20 has a pitch P1 between the bent portions.
6 = 3mm, H = 3.8mm crimp (with corrugations)
The molding is performed, and the molded wire rod thus formed is subjected to a meridian 11,
A net product was obtained by intersecting and fitting the weft lines 12 at every two bends 16.

As a result, the weight of the supporting member 3 was reduced to 30 g. Further, the corrugated wire itself has the same high pressure resistance strength as the conventional plain weave net, because it has many irregularities formed in the same manner as the conventional plain weave. Therefore, the load pressure applied to the projections can be reduced, and the occurrence of indentations on the filter medium can be reduced.

A filtration test was conducted by mounting 60 sheets of the leaf filter 1 in which the outer peripheral edges were melt-bonded to prevent leakage, to a filter device of a test plant with a spacer 10 interposed.

The fluid to be treated is a molten polymer of P and P (polypropylene) and has a treatment flow rate of 1000 to 1
200 kg / Hr. , And the magnitude of pressure loss before and after the filtration was measured.

As a comparative sample, a filter using a plain woven net product by mechanical automatic weaving conventionally used as a support member was also tested and compared.

(Comparison product) The comparison product is a plain woven mesh (6 mesh) made of stainless steel wire (wire diameter 2 mm) and has a thickness of 4 mm.
mm.

As a result, the total pressure loss of the invention was 67.9.
kg / mm ² G, which can be reduced by 10% or more compared to the comparative product, and there was no deformation due to the filtration pressure.

[0039]

As described above, the laminated metal filter according to the present invention uses a corrugated wire in which a bent portion is formed in advance as a supporting member, and skips the bent portion at the intersection of a meridian and a latitude. Due to the arrangement, the number of filter media used can be reduced without substantially reducing the number of filter media supporting points, and as a result, the outflow characteristics of the fluid to be treated can be improved.

Moreover, while reducing the overall weight,
Since it is easy to remove impurities remaining at the intersections of the support members, which has been pointed out in the past, it has high reliability, and the present invention can be applied to various types of filters. It is expensive.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an upper half together with spacers.

FIG. 3 is a plan view illustrating a support member.

FIG. 4 is a sectional view illustrating a support member.

FIG. 5 is an enlarged sectional view showing another embodiment of the filter.

FIG. 6 is a sectional view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laminated metal filter 2 filter material 3 support member 4 insertion member 11 meridian 12 latitude line 14 concave portion 15 convex portion 16 bent portion P16 uneven pitch

Claims (3)

[Claims] 1. A laminated metal filter comprising a metal filter medium and a support member for directly or indirectly supporting the filter medium, wherein the support member is formed by weaving meridians and wefts using thin metal wires. And at least one of the meridian line and the weft line, a corrugated line formed in a wavy shape in which a bent portion of a concave portion and a convex portion is repeated, and the corrugated line has one of the bent portions. A laminated metal filter characterized in that it is woven with the other fine metal wire that intersects with the above-mentioned metal wire. 2. The method according to claim 1, wherein the metal filter medium and the supporting member are
The laminated metal filter according to claim 1, wherein an interposing member formed of a punching plate or a sintered metal powder plate is disposed. 3. The laminated metal filter according to claim 1, wherein said support member is woven by crimp weaving.