CN1104553A - Flat filter and filter supporting element for it - Google Patents

Abstract

The invention relates to a filter support element (1) for supporting filter media in flat filters, comprising a dimensionally stable composite body which has sheets (3 to 11) arranged in layers one above the other, which have a coarse-meshed net structure. According to the invention, the mesh width and/or the thicknesses of the wire-shaped elements increase in the direction of flow and the uppermost net structure sheet (4) has a considerably smaller mesh width than the smallest dimension of the finest particle of the filter medium (2). The invention also relates to a flat filter in whose filter chamber the support element according to the invention is inserted in such a way that between the trough (13) receiving the support element and the support element (1) there remains no dead space.

Description

Flat filter and filter supporting element for it

The present invention relates to the supporting member of supporting filter medium in flat filter, relate to the flat filter of using this supporting member simultaneously.

For elimination solid impurity from polymer solution and polymer melt, need make the polymer penetration that to filter through filtering the hole of medium.In filter process, they can lose in a large number the pressure that should always be sent to the orientation on the housing of flat filter along flow direction.Should accomplish to make to the supporting of filtering medium and the structure that supporting force is introduced filter housings and flow freely in the clear by filtering the hole of medium.

In prior art, people's attempt reaches this purpose by the bearing plate that uses punching.They normally are equipped with the metallic plates such as steel plate in many holes.The metallic plate of these punchings is carrying the filtration medium by cancellated intermediate layer, and this intermediate layer is made up of wire, and places on the web plate that stays between all eyelets of each perforated board.The shortcoming of this structure arrangement is have the dead band in the flow region between bigger all eyelets.In order to reduce the amount in this dead band, people make the web plate stenosis that is present between all eyelets by the upper and lower sides of all eyelets on the perforated board being done the taper amplification.Though this way can not have problems at the downside of metallic plate, its upside can make mesh distortion placed on it even damage top mesh because of cutting and sharp cutting edge of a knife or a sword are arranged.Below each perforated board, be provided with cavity to collect filtrate and to flow to outlet.The wall friction power that acts on the whole liquid flow section causes a kind of flow stream velocity to distribute, and this distribution comprises very big disadvantageous difference, causes producing the difference on the corresponding holdup time.

The perforated board of prior art also requires in their edge a contact zone that does not punch is arranged, and will cause stagnation because therefore polymer melt can not flow out from the hole here.In this zone,, in the mobile territory of polymer solution or polymer solution, still be formed with the place that their are stagnated because the hole shape of eyelet can not match with the shape of housing usually fully not paying under the big cost situation.

For the hole that remedies perforated board and the difference or the protection fine mesh woven wire that filter the radius between the particle of medium can not deform because of liquid stream penetrates in the hole; the intermediate layer that people's silk screen that wire is enough thick is formed places on the hole of perforated board, makes it can not to be out of shape because of the stress that pressure reduction produces.Then will be not the thinner silk screen of the equal utmost point place these thicker silk screens above, up to the fineness of mesh reach filter medium can be supported can pass these meshes thereon and not till.

For prevent these silk screen assemblys, laterally moving of can causing all holes break-through on the perforated board, the shape of these silk screens should make it press close to the wall of filter housings, and, require to leave the gap during owing to assembling, only allow slightly mobile joint thereby form one with its.Yet, filter medium and can infiltrate through these joints.Because it is also gapped with respect to housing wall to filter medium, the polymer solution of process filtration or melt are owing to the existence of joint can be flow through around filter.In order to prevent this point, people use becket, and preferably the aluminium ring surrounds these nets.The edge of the upper-arm circumference wrapping wire net that these beckets take the shape of the letter U with cross section seals them mutually, and the edge that perforated board does not punch is also sealed.In known all embodiment, there is which floor stacked silk screen to be encapsulated in together.Yet this method with becket U-shaped upper-arm circumference wrapping wire network edge can be between the U-shaped arm and be positioned within mesh there and form cavity, and will be full of the solution or the melt of stagnation in this cavity.

DE-OS 16 60 435 discloses a kind of silk screen assembly, has wherein avoided the shortcoming relevant with becket, because the silk screen edge is welded to one another together.But this can not overcome because of the shortcoming that must use perforated board to produce, and perforated board is can produce to make dead band that filtrate is detained.

DE-AS 19 24 449 has disclosed the clad metal wire cloth of gas and fluid permeable, and it is used as filter and has the metal wire structure of multilayer.

DE-AS 18 16 118 has disclosed the device that the fibrous filtration medium of a kind of wire to sintering pressurizes, wherein the orientation of wire fiber be at random and length also be arbitrarily.

DE-AS 12 98 507 has disclosed a kind of as wire fibrous braid liquid filter, the composite members form, that strengthen.This composite members which floor wire cloth is made of, and they connect together each other firmly by the method for diffusion.This composite members is also as filter.

DE-OS 17 61 352 discloses another kind of filter, and this filter is used for spinning head and squeezer, and it filtering fineness which floor wire cloth identical or different, intraconnection is made of.

DE-GM 69 19 686 has described a kind of fibrous filter element of wire that is interconnected firmly by inside, this filter element is designed so that its porosity progressively reduces along the direction that flows through, and its method is to adopt the filter course of different-thickness and/or different fibre density.

What above-described prior art was related all is filter, because their specification, they all are not suitable for the supporting member as flat filter.

The filter support that the purpose of this invention is to provide flat filter as previously described, it can be permeated and not comprised the dead band with the short holdup time.The present invention also aims to provide a kind of flat filter of using supporting member of the present invention, this supporting member reliable operation and do not have the dead band.

Filter support of the present invention is realized that by characteristics as claimed in claim 1 flat filter of the present invention is then realized by characteristics as claimed in claim 15.

Because feature is a) to d) combination, the invention provides a kind of filter support, it can be permeated with short dead time, do not contain such zone, fluid that is filtered in this zone or filtrate are stagnated or are flowed very slowly, thereby cause chemistry or physical change, particularly be harmful to the variation of quality, for example particularly generation of hot tearing of fire damage.In order to obtain these good effects, the dimensionally stable composite members that importantly forms filter support will have coarse net order stratum reticulare, and " coarse net order " speech here is meant the size of the fineness of mesh, and it guarantees that filter support itself does not have filtering effect.

Another is to filter medium must have a particular sequence or order on flow direction mesh fineness to important point of the present invention.Specifically, even directly the top stratum reticulare of carrying filtration medium wants the little the thinnest particle that filters medium that gets can not enter composite members.

In other words, the present invention provides one to filter medium and be supported filter support on it in the filtrate (liquid side, this supporting member can be kept out the power that pressure differential produced that is taken place by the filter thing in filtering the medium process of osmosis, these filter medium and form a discharge areas, allow filtrate in whole filter scope, to flow through in this zone, thus the dead band, promptly (for example) locate to make the dead band of flow stagnation to avoid in zone and angle, recess or the nest hole etc. of the flow stagnation of structural member back of the body place formation.

Flat filter provided by the present invention comprises one by filter support of the present invention, and the profile phase of the shell bottom-valley, filter chamber of its outline and flat filter adapts to and not have a space at interval.So can spaced space with regard to guaranteeing to filter flowing of medium or the dead band occur, thereby can avoid the shortcoming of prior art.

Another important aspect of the present invention is that the cross section of wire-like element of stratum reticulare of forming the composite members of dimensionally stable is designed to fairshaped.This point can cause in the filter support occurring desirable flox condition, laterally laminar flow, particularly have flowing of horizontal shunting and be not separated but stay the periphery of wire element with longitudinal component, thereby prevented the formation in dead band.

Claim 2 and 3 relates to further improvement of the present invention, and they help to form stable laminar flow at flow direction.In addition, this thicker mesh structure support directly carries the structure of filtering medium, thereby avoid since flow resistance by filtering the distortion that the medium applied pressure is caused, this be because this mesh structure pressure introduced forms by very thick mesh, as the substructure of the bearing support of reality.

If the clean net width that one deck of direct supporting filter medium has is 0.042mm, the cross section that forms the wire element of this layer is then to be very useful about 0.036mm.Be to the maximum at diameter under the situation of the less filter of 120mm and the medium filter that diameter is 250mm to the maximum, the diameter of the filter support substructure of being made up of wire is about 1mm, and clean mesh width is 2mm.Even have under the larger-diameter situation at filter, cross section wiry also can be between about 1 to 3mm, and clean mesh width can be between 2.8 to 16mm.If the gradient segmentation at flow direction mesh width changes or changes continuously, thereby causes distortion so that thinner mesh structure can not be pressed into the coarse net order that is arranged in following structure, this also is favourable.

Supporting member of the present invention can also have any exterior contour.Yet preferably cooperate the flat filter bottom-valley, for example rotational symmetric mainly be the supporting member of the contour shape of taper, perhaps preferably have the supporting member of square-section or the supporting member of pyramid tee section.

Wire, particularly Yuan wire, its same wire-like element that is suitable for as stratum reticulare with the porous metals web frame.Under with situation wiry, the stratum reticulare preferred design becomes fabric, and this fabric can be welding, that sew up, knitting or braiding, also can be above several combination.

Flat filter of the present invention comprises one as mentioned above by supporting member of the present invention, and the exterior contour of supporting member cooperates with the bottom-valley profile phase and do not have space interval.In a preferred embodiment of the present invention, in same filter housings, have two filter chambers at least, one of them particularly encircles the form of colyliform round another with the form of ring, minimum point in the housing bottom bottom-valley of a filter chamber preferably has two recesses that each have an exit passageway at least, they along housing bottom uniformly-spaced to be provided with.

As mentioned above, the geometry of the filter support of insertion flat filter is preferably rotated symmetry and pyramid shape.

A favourable purposes according to flat filter of the present invention is that claim 20 is described.

Below with reference to the accompanying drawing that usefulness is described as an example the present invention is described in detail.Wherein,

Fig. 1 is the vertical cross section according to flat filter of the present invention.

Fig. 2 is the vertical sectional view of the flat filter after the bottom among Fig. 1 is changed slightly.

Fig. 3 is the vertical sectional view of another embodiment of flat filter of the present invention, and the flat filter among the figure comprises two filter chambers.

Fig. 4 is the plan view of two flat filter among Fig. 3.

Fig. 5 is along A, A ', B, the cutaway view of B ' line.

Shown in Fig. 1 is first embodiment of flat filter of the present invention.This flat filter comprises a rotational symmetric housing 14, and the filtration medium 2 that places above the supporting member 1 is being set in its cylinder-shaped upper part zone.Bottom 13 tapered the dwindling of housing 14 and form an outlet opening 15.Supporting member 1 is packed in the bottom-valley that is surrounded by bottom 13.The exterior contour of supporting member 1 is identical with the exterior contour of bottom-valley, does not therefore have the space to exist between bottom-valley and supporting member 1.Described outlet opening 15 is positioned at the minimum point of bottom-valley.

Can be used as the material that filters medium 2 and comprise perforated plate, the sintered body of beating pore, filter screen, or the heap loose or compacting of granular and/or fibrous material formation or the like.

Described supporting member 1 is made up of the composite members of dimensionally stable, this composite members forms a three-dimensional structure, and this three-dimensional structure comprises that (for example) is stacked and be fixed to a net and each stratum reticulare stratum reticulare 4-11 fastened to each other by wire, the particularly round mutual layering of wire.Under situation wiry, fixedly realize by (for example) sintering or welding.

The mesh width of top stratum reticulare 4 is also littler than the minimum dimension of the smallest particles that filters medium 2.Layer 4 is responsive because of its mesh carefully compare, and it covers than coarse net target zone 3 by one, and layer 3 itself also fixes with the composite members of dimensionally stable, and protection fine mesh layer 4 with exempt assemble and cleaning process in contingent damage.

The layer 5-layer 10 that the filter support of being made up of the composite members of dimensionally stable 1 is designed to link to each other with top layer 4, their mesh width and/or thickness wiry differ from one another, and the width of the thickness wiry of 5-11 layer and/or mesh increases gradually along the direction that flows at least.

In the embodiment shown in Figure 2, told three outlet openings 16 from the minimum point of filter housings bottom, rather than image pattern 1 has only an outlet opening 15 like that.

Fig. 3 to Fig. 5 shows a pair of flat filter, and the filter chamber 20 that separates in this filter housings and 21 li have inserted the filter of two independent operations, one of them annular filter chamber 21 be centered around filter chamber 20 around.In two filter chambers 20 and 21, be installed with supporting member 1 and 1 ', its structure is identical with the described supporting member of Fig. 1, only supporting member 1 ' be designed to annular.The paddy shape bottom design of filter chamber 21 become bicone shape 13 ', and contain 6 recesses 19, these 6 recesses uniformly-spaced are provided with along the round wire of a closure, and respectively are connected with an exit passageway 17 of using for filtrate in their minimum point.

Claims (20)

1; a kind of in flat filter the supporting member (1) of supporting filter medium (2); it comprises having mutually stacked layer (3-11); the composite bed spare of dimensionally stable; in the layer (3-11) a large-meshed net structure is arranged; and connect together firmly mutually; they are made up of the element of the wire-shaped with streamline section; this wire-like element is fixed at their contact point place to form the three-dimensional composite bed spare of dimensionally stable; it is characterized in that; has one among the stratum reticulare (5-11) at least along the stratum reticulare of flow direction under the top stratum reticulare (4) that directly carries filtration medium (2); the thickness of its wire-like element and/or the width of mesh increase along with flow direction; wherein; directly the carrying mesh width that filters the top stratum reticulare (4) of medium (2) is significantly smaller than and filters the most fine grain minimum dimension in the medium (2), and directly the carrying top stratum reticulare (4) that filters medium (2) has than the heavy wire linear element and than the large mesh width by one at least; the stratum reticulare (3) that is fixed on other layer is protected.

2, filter support as claimed in claim 1 (1) is characterized in that, along the layer (5-7) of flow direction below top stratum reticulare (4), the thickness of its wire-like element and/or mesh width increase continuously along flow direction.

3, filter support as claimed in claim 1 (1) is characterized in that, along the layer (5-7) of flow direction below top stratum reticulare (4), the thickness of its wire-like element and/or the width of mesh increase along the flow direction segmentation.

4, as the described filter support of claim 1-3, it is characterized in that, selected stratum reticulare (5-7) has bigger wire-like element cross section and/or mesh width on flow direction, and the every other stratum reticulare (8-11) that forms supporting member (1) substructure (12) is generally identical with selected stratum reticulare (5-7) on the thickness of its wire-like element and/or mesh width at least with regard to it.

As the described filter support of claim 1-4, it is characterized in that 5, that described supporting member (1) has is rotational symmetric, the shape of cone particularly.

As the described filter support of claim 1-4, it is characterized in that 6, it is one leg-of-mutton that described supporting member (1) has, particularly a rectangular cross section.

As the described filter support of claim 1-6, it is characterized in that 7, stratum reticulare (3-11) is made up of wire, wire is fixed by sintering or welding at the contact point place.

8, filter support as claimed in claim 7 is characterized in that, described wire is the circular metal silk.

As claim 7 or 8 described filter support, it is characterized in that 9, described stratum reticulare (3-11) is the wire cloth that arbitrarily engages.

As claim 7 or 8 described filter support, it is characterized in that 10, described stratum reticulare (3-11) is the wire stitches thing.

As claim 7 or 8 described filter support, it is characterized in that 11, described stratum reticulare (3-11) is the wire knitted fabric.

As claim 7 or 8 described filter support, it is characterized in that 12, described stratum reticulare (3-11) is a wire braid.

As the filter support of one of claim 9-12, it is characterized in that 13, described stratum reticulare (3-11) is the combination of wire cloth, sutures, knitted fabric and braid.

As the described filter support of one of claim 1-6, it is characterized in that 14, it is made up of porous metals composite bed spare.

15, a kind of flat filter has at least one filter chamber, and at least one filters medium (2), at least one supporting member (1) and a housing (14), the bottom of described housing (14) has a bottom-valley (13,13 ') at least, and the minimum point of bottom has an outlet opening (15 at least, 16,17), it is characterized in that it comprises the described supporting member (1 as one of claim 1-14,1 '), the exterior contour of supporting member and the exterior contour of bottom-valley are suitable and do not have space interval.

16, flat filter as claimed in claim 15 is characterized in that, the bottom-valley of the bottom of housing (13) have the shape of cone, is limited by surface line straight or song around it.

17, flat filter as claimed in claim 15 is characterized in that, the bottom-valley of described housing bottom (13) have the shape of pyramid, is limited by surface line straight or song around it.

18, as the described flat filter of one of claim 15-17, it is characterized in that in a common housing, it comprises two filter chambers (20 at least, 21), one of them filter chamber (21) center on another filter chamber (22) with the form of ring, the particularly form with torus.

19, flat filter as claimed in claim 18, it is characterized in that, minimum point in the bottom-valley of the housing bottom of described filter chamber (21) has two recesses (19) at least, two recesses (19) at least respectively have an exit passageway (17), this recess (19) along housing bottom with spaced set.

20, utilize as the described flat filter of one of claim 15-19, by the part or all of synthetic filaments of spinning technique production or many components silk of solution or melt, the filter housings of flat filter (14) then is a part of inserting spinning head and spinneret assembly in process of production.

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