JPS62250920A - Filter element for fluid - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention can be applied in principle to German patent application no.
49, a filter element fitable or fitted into a filter casing with supply and discharge connections for fluid, comprising a plurality of circular to n-gonal shapes. formed from substantially congruent filter sections of, which filter sections are planarly connected to the drainage support layer and/or planarly supported on the support layer;
In addition, the filter section and the support layer are stacked and sealingly connected to each other at the periphery so that a certain amount of fluid can flow from the casing chamber through the filter element and into another casing chamber. Regarding.

PRIOR ART In the case of the known stacked filter elements consisting of flat sections, the internal and external seals of the various flow paths are combined with silicone-based packing materials, different membranes and support materials. This is done with a pressure distribution mask. Different materials that are mutually adapted with respect to their sealing properties do lead to satisfactory sealing, but this limits the use of filter elements of this kind in the field of corrosive media, since the presence in the filter element This is because not all materials have equally good properties with respect to corrosive media.

Corrosive media are used in particular when manufacturing microelectronic components.

Microelectronic devices (wafers), especially the next generation of increasingly smaller dimensions, can only be fabricated using particulate-free filtered chemicals. The yield of usable chips depends for this purpose on the purity of the etching medium, which is used in part under harsh conditions and in part is highly corrosive. When producing such elements under clean room conditions, the smallest possible dimensions are desired for the filters which are utilized immediately before the use of chemicals, since the space available under laminar flow conditions is desirable. This is because they are extremely expensive.

The subsequent assembly, which can never be eliminated, results in etching media, organic solvents and gases to be filtered through such filter elements.

Liquid: Sulfuric acid (concentrated) Chromic acid (maximum concentration) Caroic acid (sulfuric acid and hydrogen peroxide): 'Piranha Etch' Nitrate Acid Hydrofluoride Phosphate Trichloroacetic acid Hexafluorosilicate Ammonium hydroxide Perchloroethylene, Trichloroethane, Trichlorethylene , methylene chloride, monochlorobenxylene, butyl acetate, cellosolve acetone, cyclohexanone dioxane, tetrahydralane gaseous dirane, dichlorosilane, silicon tetrafluoride, boron trifluoride, carbon tetrafluoride, diborane, boron trichloride, trifluoride Boron Ammonia Hydrogen Arsenide The highly corrosive chemicals used up to temperatures of 80 DEG to 140 DEG C. severely limit material selection. Glasses or metals are not depicted due to the solubility of ions. Common industrial plastics are attacked oxidatively under the harsh conditions mentioned and contaminate chemicals with their decomposition products.

Polymers that are partially fluorinated themselves, such as PVF or P
VDF cannot be used for some of the above applications. These are dissolved or degraded after prolonged use. Therefore, usable polymer materials include:
Only a small area of inert highly substituted fluoropolymers remains: FTFE (poly-tetrafluoro-ethylene)20 e.g. Teflon, HOstaflOn FEP
(Verfluoroethylene-propylene copolymer): For example, Teflon FERo, Neoflon”, T
e f 1e xe ETFE (copolymer of ethylene trifluoroethylene), partially fluorinated: e.g. Tefzel
■、Ho5toflon KT■、Af□on■PPA
/TFA (Verfluoro-ethylene-vinyl ether copolymer): For example, Teflon PFA'', Ho5t
aflon TFA” (E)OTFF (Copolymer of I-chlorotrifluoroethylene and ethylene): For example ■ ■ Ac1ar IIHalar All these materials are difficult to process. PTFK cannot be processed thermoplastically. Yes, and other materials can only be processed at extremely high temperatures.

A membrane can be produced from FTPK as described in German Patent Application No. 2,123,316. According to known technology, these membranes can be used as filters,
For example, it can be processed into a candle filter.

To produce filters with higher efficiency or packing density and high chemical stability, extremely thin, approximately 80%
Planar membranes consisting entirely of voids require special measures and techniques both in post-processing and during use. The object of the present invention is to solve the problems that arise in this case.

This is because the known seals and presses using elastic packing members are unsuitable for such applications.

SUMMARY OF THE INVENTION It is therefore an object of the invention to construct a filter element of the type mentioned at the outset in a simple manner in such a way that press packings and special backing elements inside the filter element can be dispensed with. Ta.

Means for Solving the Problem The object according to the invention is achieved by providing a filter element for fluids of the type mentioned at the outset, in which a relatively large filter surface is surrounded by two upper and lower filter sections and a supporting layer. an annular closed sealing joint by welding or gluing inside, the inner annular surface bounded by it having a through hole for directing the fluid at right angles to the filter surface, and having a lantern-shaped In order to form layers and composite configurations, the mutually adjacent filter sections of each adjacent pair of filter sections are sealingly connected to each other by welding or gluing along their outer edges, the bonded sections having a supporting layer being sealed. The present invention is solved in that one side of all filter sections with a support layer opens into a housing chamber and the other side of all combined filter sections with a support layer opens into another housing chamber via a through opening.

Advantageous embodiments for filtering particularly highly corrosive chemicals are described in the embodiment section of the patent claims.

OPERATION The lantern-shaped form of this particular structure and the associated flexibility in selecting the filter materials to be used and the means to assist in filtration and fluid conduction make it possible to achieve maximum surface area with minimum volume. can. Components and materials (
) from a chemical point of view can be reduced to a minimum. With a minimum number of basic units, a large variability of area is guaranteed with a single component.

The invention will now be described in detail with reference to the illustrated embodiments.

The simplest bonded membrane made of fluorine polymer will be described below. PTFE is the most difficult to bond or weld. Special membranes made of PTFE are difficult to bond and weld due to their structure. FTFB as known for example from West German Patent Application No. 2123316
! The membrane consists of a fibrillar and knotted structure and a large number of air bubbles, which have thermally insulating properties and thus react particularly well with welding techniques. Severe welding conditions (
At high temperatures and pressure peaks) there is a risk of damage to sensitive membranes.

For the application according to the invention, a PTFK membrane 9 is preferably used which is already coated with one or two thin support layers to form a laminate.

In this case, a fabric 10 and a fleece 13 made of a chemically inert thermoplastic fluoropolymer with a softening point as low as possible are used. As drainage support layer, a fabric 11, likewise based on fluoropolymer, is used in somewhat larger dimensions.

In the same sense, selectively engraved and optionally perforated sheets 12 are used.

According to FIG. 2, first the two filter sections 9 are superimposed on the stacked welded fabric 10 and sealed in the central region with the annular weld seam 17, and in order to drain the filtrate into the inner annular region. A useful through hole 16 is provided.

In this embodiment, the filter section 9 has a rectangular shape with the integrated welded fabric 10. These are stacked on a pair of electrodes as shown in FIG. Individual welds 17' are then made at the outer periphery to form a lantern-shaped layer and composite configuration.

In order to be able to handle the filter element 8 as a disposable unit during assembly and disassembly, the filter element 8 has on one side a closure member 18 covering the central through hole 16;
The closure member has a support layer 10 located below it at its outer periphery.
The filter section 9 has a sealing connection. Similarly, the other side of the filter element 8 is provided with another closing member 19 with a central connection opening 19' and is joined to the filter element 8 at 17 at the outer periphery or in the central region. All through holes 16 of the filter element 8 are connected to the connecting tube piece 1 of the closure member 19.
It opens at 9'.

As can be seen from FIGS. 8 and 9, the housing 1 consists of two housing parts 2 and 3, which are likewise designed for the filtration of highly corrosive media, for example of PTFE. In addition to the connection pieces 4 and 5 for inflow and outflow, outflow and outlet openings 6 and 7 are provided.

In order to ensure handling of the filter element 8, the relatively rigid closure members 18 and 19 are interconnected by a number of panning rolls 20, which stabilize the filter element 8 in the axial and radial directions. In this case, in order to optimize the packing density and to obtain a defined flow path, the individual filter sections 9 are provided with drainage support layers 10, 11, which differ from the simple drawings according to FIGS. 1 to 7. Closely attached to 12.13.

In the variant embodiment of FIG. 4, the filter sections 9 are supported on both sides by welded fabrics 10 and are constructed in a laminated manner, while adjacent filter sections 9 do not have integrated welded fabrics. However, in the lantern-shaped layer and composite configuration, both filter sections 9 are supported on both sides by welded fabrics 10.

In one variant embodiment of FIG. 5, the welded fabric 11 is arranged between the filter sections 9 without being joined and is joined to the filter sections 9 or the closure part 18, 19 exclusively at the welded edges 17 and 17'.

In the variant embodiment of FIG. 6, a liquid-imprinted sheet with through holes arranged crosswise relative to its longitudinal grooves is used as the support layer.

In the variant embodiment according to FIG. 7, there is additionally a filter section 9 and a fleece 13 as a laminate supported by a welded fabric 11.

FIG. 7 corresponds to FIG.

Among the flat forms, particularly in expensive filter materials, for example, as shown by the squares in Figures 8-10,
An n-gon shape without cuts is a preferred embodiment. However, in general a large number of contour shapes are possible, for example a circular or cylindrical embodiment according to FIG. In this case too,
For ease of handling and stabilization, the filter element 8' has two parts connecting the two closure members 18', 19'.
They are connected by two panda rolls 20. 10th
The filter element 8 according to the figure can be simply connected to the connecting pipe 4 after removing the casing part 2, so that the casing can be divided into two chambers 14 (retentate chamber) and 15 (permeate chamber). can.

12-14 show advantageous embodiments. In order to waste as little as possible from the very expensive material of the filter element, the upper and lower closing parts 18,19 are constructed as thin sheets or as a final filter membrane with perforated sheets 12. The latter only has a protective function for membrane 9. A connecting adapter 19'' as an outflow pipe piece is welded or glued directly to the lower closure member 18.

The filter element 8 is formed from a membrane 9 provided with perforated sheets 12 on both sides according to FIG. 14, in which case each individual module M (for example shown on the left side of FIG. 14) is can be manufactured and individually tested.

In order to be able to stabilize the filter element 8 in the casing and to achieve the most favorable packing density, the filter element 8 is held at intervals by reusable clamps 24 at the top and bottom. Reusable press plate 2
It is covered by 1.22. For tightening, the bolt 24 is fixed in the longitudinal direction and can be easily fitted into the support groove 23, which is open on one side of both press plates 21 and 22. The lower press plate 22 has a through hole 22' for the connection adapter 19'.
has. Therefore, only the filter element 8 with the connection adapter 19# forms a consumable part. The filter element 8 shown in FIGS. 12-14 can be fitted into the casing of FIGS. 8 and 9. The individual elements according to FIGS. 1 to 7 and 14 are shown in close contact with one another in the operating state and with large spacings for purposes of illustration only.

It has been found that for special fields of application, instead of static filtration, it is possible to carry out dynamic filtration, in which the retentate is constantly circulated in the retentate chamber 14. In this case, the filter layer overflows in layers around the closed core 17. For this purpose, it may be advantageous to arrange the closed core 17 and, accordingly, the outlet connection pieces 4.19' and 19'' eccentrically, that is to say close to the outer circumference of the filter element 8.

Instead of a reusable casing 1, the filter element 8 can also be enclosed in an encapsulated disposable casing.

Connection adapter 19" for casing 1 or filter element 8
The O-ring seal 25 located therein can be formed from an elastic sealing element surrounded by PTFE, so that for the filtration of highly corrosive media the entire filter unit can also be formed from PTFE.

In this case, using a corresponding welding aid, PTF
It is possible to transfer the technique described for E to other, directly non-weldable materials. The welding aid may consist of an annular welding sheet which is positioned within the annular region to be joined and which causes the fixation of materials that cannot be directly welded.

The above-mentioned lantern-shaped joining technology can be applied to, for example, polyamide P, polysulfone, polypropylene, polyvinylidene difluoride,
It is self-evident that it can be carried out using materials such as polyester or polyurethane which can be welded by themselves.

[Brief explanation of drawings]

FIG. 1 shows an axial section through a filter element configured in the form of a lantern; FIG. 2 shows the basic unit of two filter sections, one with a centrally arranged sealing connection and the other with a supporting layer. , FIG. 6 is a detailed view of a portion of the upper closure member, FIG. 4 is a detailed view of an embodiment in which the structure of the filter section with support layer differs from that in FIGS. 1 to 6, and FIGS. 5 and 6. 7 is a detailed sectional view of the basic element of another embodiment, FIG. 8 is a front view of the casing housing the fill element, and FIG. 9 is a detailed view of the basic element of the other embodiment. FIG. 10 is a perspective view of the filter element shown in FIGS. 1, 8 and 9; FIG. 12 is a schematic sectional view of an advantageous embodiment of the filter element, FIG. 13 is a bottom view of the filter element according to FIG. 1, and FIG. 14 is a detailed view of the filter element. 1... Casing, 2, 3... Casing part, 4
゜5.6.7... Connection part, (5'... Outlet), 8
...filter element, 9...filter intercept, 10.1
1... Supporting layer (fabric), 12... Supporting layer (sheet)
, 13... Support layer (fleece), 14... Retained liquid chamber, 15... Permeated liquid chamber, 16... Through hole, 17.17
'... Welding area, 18.19... Closing member, 19'
, 19"...Connection adapter, 21.22...Press plate, 22'...Through hole, 23...Support groove, 24
...Tighten with the holding member (tighten with bolt), 25...0
Ring packing 290,000 rH Ni! ? 12,,,,,. 13,,,,, #18... Closing member 2gδ d&# JiEi':1II 8',,,,. 25 ,,,,, (J 1.y Gua, Tsuki. Ni!ff 2Mζノ3

Claims (1)

Claims: 1. A filter element fitable or fitted into a filter casing with supply and discharge connections for fluid, comprising a plurality of circular to n-gonal, substantially formed from filter sections of generally congruent shape, which filter sections are connected in a planar manner to a draining support layer and/or supported in a planar manner on the support layer, and the filter section is formed in a planar manner by a draining support layer and/or is supported in a planar manner on the support layer, and the fluid is removed from the casing chamber in a fixed amount. In the type in which the filter section and the support layer are stacked and sealingly connected to each other at the periphery, in order to allow the flow to flow through the filter element into another casing chamber, there are two upper and lower parts in each case. The filter section (9) and the support layer (10, 11, 12, 13) have an annular closed sealing joint (17') by welding or gluing inside the relatively large surrounding filter surface; The inner annular surface thus confined has through-holes (16) for directing the fluid at right angles to the filter surface, and each adjacent filter section forms a lantern-shaped layer and a composite configuration. A pair of mutually adjacent filter sections (9) have their outer peripheral edges (17'
) are also sealingly connected to one another by welding or gluing, with one side of all the joined filter sections (9) having a supporting layer opening into one housing chamber (15) and having a supporting layer. A filter element for fluids, characterized in that the other side of all connected filter sections (9) opening into a further casing chamber (14) via a through hole (16). 2. Filter element according to claim 1, in which the through opening (16) is arranged in the central region. 3. Filter element according to claim 1, wherein the filter section (9) and/or the support layer (10, 11, 12, 13) are made of a weldable plastics material. 4. Weldable support layer (10, 11, 12, 13) made of plastic on one or both sides of the filter section (9)
The filter element according to any one of claims 1 to 3, wherein the filter element is laminated. 5. The filter element according to any one of claims 1 to 4, wherein the filter section (9) is formed based on a polymer highly substituted with fluorine. 6. Support layer is fleece (13), woven fabric (10, 11),
6. Filter element according to claim 1, wherein the filter element is formed from an engraved and perforated sheet (12) or a grid. 7. The filter according to any one of claims 1 to 6, wherein the support layer (10, 11, 12, 13) is formed based on a polymer highly substituted with fluorine. element. 8. The through hole (10) of the filter section (9) is closed on one side by the closed closure member (18) and on the other side by the through hole (16).
) is covered by a closing member (19) which further guides the closing member (18, 19), the two closing members (18, 19)
8. The filter element according to claim 1, wherein the filter element is sealingly joined to the outer periphery or central region of the filter section (9) adjacent to the filter section (9). 9. Filter element according to claim 1, characterized in that the membrane (9) is covered on both sides with perforated and stamped drainage sheets (12). 10. Filter element according to claim 1, wherein the closure members (18, 19) are formed by a thick sheet. 11, connecting adapter (19, 1) as part of the filter element (8) to the closure member (19) having the through hole (16);
12. A filter element (21, 22) on which the filter element (8) covers the closure member (18, 19); , the press plate (21,
22), which is mechanically stabilized by a clamping holder or clamping bolt (24) that fits into a supporting groove (23) open on one side.
The filter element according to any one of the preceding items.