EP2498893A1

EP2498893A1 - Filter

Info

Publication number: EP2498893A1
Application number: EP10774141A
Authority: EP
Inventors: Markus Dewes
Original assignee: Hydac Filtertechnik GmbH
Current assignee: Hydac Filtertechnik GmbH
Priority date: 2009-11-10
Filing date: 2010-10-27
Publication date: 2012-09-19
Also published as: WO2011057716A1; CN102648035B; JP2013509996A; DE102009052613A1; JP5698252B2; US20120199529A1; CN102648035A; US8945388B2

Abstract

The invention relates to a filter comprising at least one first (2) and at least one second filter medium (3), said filter media defining therebetween a flow space (4) in which a device (5) for separation and flow guidance is inserted and divides the flow space such that a functional space (25, 26) is disposed adjacent to the first (2) or the second filter medium (3), respectively. The first filter medium (2) defines a hollow space (21) toward the outside and the second filter medium (3) defines a hollow space (22) toward the inside, and each of the hollow spaces (21, 22) can be connected to at least one fluid duct (23, 24). The filter is characterised in that the flow space (4) comprising the two functional spaces (25, 26) thereof can be connected to at least one further fluid duct (27) that is separated in a fluid-tight manner from the other fluid ducts (23, 24).

Description

filter

The invention relates to a filter having at least a first filter medium and a second filter medium, which define a flow space between them, into which a device for separation and flow line is inserted and subdivided such that in each case one functional space encloses the first or the second filter medium adjacent, wherein the first filter medium defines a cavity to the outside and the second filter medium, a cavity inwardly, and wherein the cavities are each connected to at least one fluid guide. Such a filter has become known from DE 31 03 723 A1. The known filter for liquids has two concentric depth filter tubes, which are arranged between a first and a second cover with their end faces so that they are connected in parallel between an inlet and a drain, and in the two between see Depth filter tubes an annular space is formed. In the annular space, a spacer is arranged, which consists essentially of a cylindrical tube part with corrugated wall and fixes the position of the two depth filter tubes to each other. Due to the corrugated wall of the pipe part of the annulus is divided into approximately equal flow channels and inlet channels. The inlet channels are turned towards the inner depth filter tube and open at the bottom and thus also connected to the inlet. The drainage channels are turned towards the outer depth filter tube and open to the top. The thickness of the annulus can be kept comparatively small in this type of spacer, the flow resistance remains relatively low. The known filter operates as a depth filter, in which the two depth filter tubes are connected in parallel with each other, whereby a relatively long service life is achieved. The inflowing into the housing through the inlet pressure fluid flows past the outer edge of the first cover in the annular space between the housing and outer filter tube. A part of this pressure medium flows radially through the outer depth filter tube and passes cleanly into the drainage channels, where it flows upwards and between the first cover and the upper end to the outlet. Another part of the uncleaned pressure medium flows from below into the inlet channels of the spacer. From there it flows radially through the inner filter tube and also via a perforated plate cylinder to the drain.

Filters are known in a variety of embodiments and sizes for a variety of applications for filtering and cleaning liquid or gaseous fluids. There are known in the prior art filter devices in which a single hollow cylindrical filter element is arranged in each case in the interior of a filter housing. Through an inlet of the filter housing dirty liquid is supplied, which flows through the filter medium from outside to inside. The filtered liquid is then removed via a fluid outlet in the filter housing for further use. Such filters have a bypass valve as a possible bypass device in order to avoid malfunctions during operation, in particular when there is an increase in the pressure difference between the fluid inlet and the fluid outlet in the case of a filter medium contaminated by contamination. In such a case, uncleaned fluid can then be passed on directly to the fluid outlet. Furthermore, WO 02/062447 A1 discloses filters in which, during normal operation, ie when the bypass valve is closed, the fluid to be cleaned first flows through a first filter medium from outside to inside. Coaxially to the first filter medium, a second filter medium is arranged, which in turn surrounds an inner second cavity, from which the fluid can flow off via a fluid outlet of the filter housing. Upon opening of the bypass valve due to a clogging of the first filter medium enters the impure fluid via the bypass valve in the first filter cavity, flows through the second filter medium from outside to inside and then exits in such a purified from the fluid outlet of the filter housing. In normal filter operation, in addition to coarse filtration by means of the first filter medium, fine filtration can be achieved by means of the subsequent second filter medium. There are also known filters which predetermine two flow paths parallel to one filter medium each for the fluid entering a filter housing. A first and second filter medium are preferably arranged coaxially with each other in a common filter housing. The filter media are in each case simultaneously impinged with uncleaned fluid from the outside thereof, so that a filter surface increase of 50% or more over known single-element solutions results for the filter media simultaneously flowed through during operation. In order to achieve a longer service life of the filter or to clean different fluids with one and the same filter, however, the known technical constructive measures are not fully suitable.

In view of this problem, the invention has the object to provide a filter whose space is used efficiently and allows simultaneous filtration of various fluids during a filtration operation, with an improved fluid passage through the filter achieved and the performance should be improved sol l. According to the invention this object is achieved by a filter having the features of claim 1 in its entirety. According to the characterizing part of patent claim 1, the flow space with its two functional spaces can be connected to at least one further fluid guide, which is separated from the other fluid guides in a fluid-tight manner. This results in the advantage that the first filter medium and the second filter medium optionally switchable in series or in parallel, and / or with a single fluid stream or with a first fluid stream and at least one second fluid stream separated from the first fluid stream, and / or in the same or opposite direction can be flowed through. As a result, the filter according to the invention can optionally be used for the separate filtering of different unfiltrates or for the stepwise filtering of a non-filtrate. Due to the different flow directions or charging options with unfiltered material and the emptying of filtrate from the filter, a wide variety of possible uses for the filter according to the invention result.

By means for the separation and flow conduction of a first fluid flow for the first filter medium from a second fluid flow through the second filter medium, a first fluid flow can simultaneously be conducted to the first filter medium and a second fluid flow that is equal to or different from the first fluid flow reach the second filter medium , In this case, it is possible to use the first filter medium for a preliminary or coarse filtration of a fluid flow and, after passage, subject the filtrate with the aid of the second filter medium to a further filtration, in particular fine filtration. Optionally, the service life of the filter can be extended in this way. With a filter according to the invention, it is also possible to carry out a simultaneous filtration of two different fluids or media. be taken, in which the flow guide the first fluid flow separated from the second fluid flow leads to the respectively assignable filter medium for a separate filtering process. It follows from this structural measure the possibility to expand the purpose of the filter by two or more different fluid streams can be filtered simultaneously with this.

The filter media may be formed as a surface, such as planar layers with the means located therebetween for the separation and flow conduction of the two fluid streams. However, it can also be advantageous to arrange the at least first and second filter medium concentrically with one another, for example in the manner of a cylindrical filter cartridge. The flow space formed by the device for separation and flow line is provided cylindrically between the filter media.

The means for flow line and separation allows, for example, a non-filtrate, which seen in a flow of the first filter medium from outside to inside, seen in the radial direction of the filter, this flows through so far can be derived from the filter. A second filtrate, which is formed from the inside to the outside to the flow of the second filter medium, can be simultaneously separated from the first filtrate separated by the means for separating and flow of fluid streams from the filter thereof. The flow space formed between the filter media can be subdivided into two or more regions which are functionally separated from one another. The functionally separate region can be formed, for example, by juxtaposed channels, which are optionally open to the first filter medium and to the second filter medium. The channels can serve both for the removal of filtrate and for the supply of unfiltered material to the first and second filter medium. The mutually separate channel guides may be formed, for example, of wave-shaped individual channels, which extend between two boundary walls. The boundary walls in turn adjoin the respective inner and outer walls of the filter media and may have a porous or perforated structure. The channels, after passage of the fluid through the boundary walls, further conduct the fluid separately. The respective fluids may all be in the form of non-filtrate or mixed as filtrate and as unfiltrate. The fluid streams may have different flow directions in the channels relative to one another or identical flow directions. For example, is it

Fluid flows at different temperatures, so the inventive device for separation and flow of the first and second fluid stream allows a guide of these streams in the countercurrent principle for the purpose of heat transfer to the respective colder medium.

In order to enable a filtration to be carried out with two or more filter stages, it is advantageous to form the first filter medium with a filter fineness different from the second filter medium. Thus, by means of the separation and flow line, the first fluid stream present as a non-filtrate can be led to the first filter medium, for example, and the fluid partially filtered by the first filter medium can be forwarded from the first filter medium to the second and optionally further filter media. In this way, the flow-guiding device enables a series connection of at least two filter media in a single filter housing.

Depending on the material properties of the fluid to be filtered, the filter media can be configured in many ways. Thus, the nonwovens used can consist of polymeric fibers or filaments. The materials used are preferably polyolefin, in particular polyethylene and / or polypropylene, and also polyesters, in particular PBT and / or PET. The filter media can be prepared in a known manner, such as spunbond nonwoven or staple fiber nonwoven fabric in the wet-laid or dry-laid process. In addition, the filter layers can also be produced by meltblown processes or be formed as nanofibers. In addition to so-called filter papers are Mineralfaservliese or glass fiber nonwovens used. For mineral fibers, for example, nonwovens based on aluminosilicate, ceramic, dolomite fibers or fibers of basalt and the like can be used. All glass types such as E-glass, S-glass, M-glass or C-glass can be used for glass fiber nonwovens. The filter media may also be pleated or have a different surface shape.

It may also be advantageous to change the pore size or filter fineness of the filter media over their depth. Thus, the filter fineness on the inlet side for unfiltered material may be lower than on the outlet side of the filtrate of the respective filter medium.

In a particularly preferred embodiment of the filter, the two filter media or further filter media are arranged axially between a bottom part and a cover part of the filter and in this way the filter can be modularly constructed. The filter can be taken from a first and a second filter medium with the means for flow line a filter housing together and used there again.

In the following the filter according to the invention will be explained in more detail with reference to the drawing.

It show in principle and not to scale the Fig. 1 in the manner of a longitudinal section a view of the structure of a filter according to the invention;

Fig. 2 is a partial perspective view of a perspective view

Device for flow line, can be used in a between the filter media limiting flow space after the

Fig. 1.

In FIG. 1, a filter 1 for the separate filtering of different unfiltrates or for the stepwise filtering of a non-filtrate is shown in a detail in a perspective, principal and not to scale view. The filter 1 has a first filter medium 2 and a second filter medium 3. The filter media 2, 3 are preferably nonwovens made of polymeric fibers with two different filter fineness, the second filter medium 3 preferably being intended to have a greater filter fineness than the first filter medium 2.

In the embodiment shown in Fig. 1, the filter media 2, 3 as a tubular, in particular cylindrical components ausgebi. The first filter medium 2 and the second filter medium 3 have the same axial lengths L and are arranged at a constant radial distance from one another in the filter 1. A disk-shaped planar bottom part 14 has a peripheral edge 16 and a further, in the radial direction to a longitudinal axis 8 of the filter 1 inwardly offset edge 1 7. The peripheral edge 16 and the edge 1 7 have the same height and are not shown Adhesive bonded to an end portion of the outer first filter medium in a sealed manner. The second filter medium 3 is fixed in the same way with its end portion between the bottom part 14 upstanding edges 18, 19. A cover part 1 5, which is opposite to the bottom part 14 at the other axial end of the filter 1, is formed comparable annular. The cover part 1 5 has a width which corresponds to the thickness of the two filter media plus the radial distance of the filter media 2, 3. In the same way as in the bottom part, the edges 1 7, 1 8, 19 and the outer peripheral edge 16 are arranged on the cover part 15 and serve for the positive and cohesive fixing and spacing of the two filter media 2, 3. The bottom part 14 has openings 20 between the two filter media 2, 3, through which fluid flows 6, 7 can be introduced or discharged between the filter media 2, 3 around the entire circumference of the bottom part.

The first filter medium 2 defines an annular first cavity 21 to the outside, the second filter medium 3 a likewise annular second cavity 22 to the inside. The two cavities 21, 22 are connected to a respective fluid guide 23, 24, more precisely, the first cavity 21 to the first fluid guide 23 and the second cavity 22 to the second fluid guide 24. However, it is also conceivable, both cavities 21, 22 to a joint fluid guide 23 or 24 to connect.

FIG. 1 shows the various flow directions or charging options with unfiltered material and the emptying of filtrate from the filter 1. The first fluid stream 6 can be guided, for example, from the radially outer peripheral surface or side 12 of the filter 1 to the first filter medium 2 and after the passage of the first filter medium 2 onto the clean side 13 in a device 5 for flow conduction and separation to the bottom part 14 and are derived from there through the openings 20. A second fluid flow 7 can simultaneously be directed radially outward from the inside 12 'of the filter 1 onto the second filter medium 3 and, after passage of the second filter medium 3 in the device 5 for flow conduction and separation through the openings 20 through the bottom derive part 14, and thus provide another connection. The second fluid flow 7 can also be formed by the filtrate of the first filter medium 2, so that the first and second filter medium 2, 3 are connected in series in this mode of operation of the filter 1.

The device 5 for flow line and separation of a first fluid flow 6 and a second fluid flow 7 is shown in fragmentary form in FIG. The device 5 is preferably made of plate-like, formed in the manner of a corrugated or web plate thin-walled channel guides 9, with side by side and parallel to a longitudinal axis 8 of the filter 1 extending single channels 10. The individual channels 10 have in the embodiment shown, each a substantially dreiek- kigen cross section. The individual channels 10 are bounded by a respective boundary wall 1 1, which are arranged opposite one another relative to the individual channels 10. The boundary walls 1 1 are fluid-permeable in the sense that they can pass particles and carrier liquid of the fluid streams 6 and 7.

The device 5 for the flow line can be formed from an inert plastic material or metal material acting opposite to the fluid streams to be filtered. It allows the separate receiving and discharging of fluid streams 6, 7 with respect to the filter media 2, 3. The boundary walls 1 1 can be formed from flat, perforated plates, and the individual channels 10 from a to a corrugated profile 1 1 'converted Plate made of sheet metal or a thermoplastic. For the sake of simplicity, however, the pertinent perforation or perforation is omitted in FIG. The plates and the molded corrugated profile can be bonded together by adhesive bonding or by gluing. The boundary walls 1 1 and the channel guides 9 or individual channels 10 may also, as FIG. 2 illustrates, be integrally formed as an injection molded component made of thermoplastic material. The filter media 2, 3 can be cohesively or by gluing or positive and non-positive by appropriate shaping with close tolerances with the device 5 to connect the flow line and separation with this. Thus, a manageable unit of the two filter media 2, 3 and the device 5 to the flow line and fluid separation may be formed. The individual channels 10 may be formed rectangular or square instead of the triangular cross-section through the corrugated profile 1 1 '.

By the device 5, more precisely, its corrugated profile 1 V, a first functional space 25 and a second functional space 26 are defined, each consisting of channel guides 9 and individual channels 10. By means of the functional spaces 25, 26 arranged between the boundary walls 11, the flow space 4 is subdivided accordingly in the inserted state of the device 5 for separation and flow conduction, wherein the first functional space 25 adjoins the first cavity 21 and the second functional space 26 the second cavity 22 is. Via the openings 20 at the bottom end of the filter 1, the two functional spaces 25, 26 can be connected to a further fluid guide 27, wherein two further fluid guides for the first functional space 25 and the second functional space 26 can be provided. The further fluid guide 27 is fluid-tightly separated from the fluid guides 23, 24 configured here as an inlet and formed as a drain.

The fluid flow directions in the embodiment shown in FIG. 1 are rectified in the individual channels 10, which is filtrate which has formed after passage through the first filter medium 2 and the second filter medium 3. The device 5, according to FIG. 2, can be used concentrically in the cylindrical flow space 4 in such a way that the respective inner side of the filter medium 2 and the outer side of the filter medium 3 can be supported on the adjacent perforated boundary walls 11 in a pressure-stable manner, this being the zelkanäle 10 stiffening intermediate wall material counteracts the extent so far acting from the outside pressure and the pressure acting from the inside fully. In this way, a particularly stiffened filter unit can be achieved as a tradable component.

Instead of the concentric arrangement shown in FIG. 1, it is also possible in the sense of a stack filter to form filter medium 2 and filter medium 3 as plate material, wherein the then formed flow space 4 is in turn filled by the associated device 5. In addition to a shown arrangement with only two filter media 2, 3, of course, there is the possibility of further, not shown, filter media in a concentric or stapeiförmiger arrangement to a filter 1 to assemble comparable. It is also possible, through the openings 20 in the bottom part 14, to charge the two filter media 2, 3 equally with a non-filtrate. In reverse to the arrow direction shown, the unfiltrate stream can then be supplied to the filter medium 2 from inside to outside via the flow space 4, again through the device 5, or pass therethrough transversely to the direction of the longitudinal axis 8 the filter medium 3. Likewise, it is possible to feed only one filter medium 2 or 3 in such a way with unfiltered material through the opening 20 and the other filter medium 3 or 2 as before, as described, then feed the other corresponding openings 20 for Filtratabfuhr.

Claims

P a t e n t a n s r ü c h e

Filter with at least a first (2) and at least a second filter medium (3), which delimit a flow space (4) between them, into which a device (5) for separation and flow management is inserted and divides it in such a way that a functional space ( 25, 26) is adjacent to the first (2) or the second filter medium (3), the first (3) filter medium (2) having a cavity (21) to the outside and the second filter medium (3) having a cavity (22) to the outside limited on the inside, and wherein the cavities (21, 22) can each be connected to at least one fluid guide (23, 24), characterized in that the flow space (4) with its two functional spaces (25, 26) is connected to at least one further fluid guide ( 27) can be connected, which is separated from the other fluid guides (23, 24) in a fluid-tight manner.

Filter according to claim 1, characterized in that the first and second filter medium (2, 3) and the flow space (4) are arranged concentrically to a longitudinal axis (8) of the filter (1).

Filter according to claim 1 or 2, characterized in that the flow direction for a filter element that is arranged too extreme

(2) on the filter (1) from the outside to the inside and for the adjacent filter medium (3) from the inside to the outside in the common flow space (4).

Filter according to one of claims 1 to 3, characterized in that the device (5) for flow conduit has separate channel guides (9) which are used to transport the individual fluid streams (6, 7) from the respective first and second filter medium (2,

3) coming within the flow space

(4) serve.

5. Filter according to claim 4, characterized in that the separate channel guides (9) are formed from wave-shaped individual channels (1) which extend between two boundary walls (1 1), each adjacent to the respective inner and outer walls the filter media (2, 3).

6. Filter according to claim 5, characterized in that the boundary walls (1 1) are perforated.

7. Filter according to one of the preceding claims, characterized in that the first filter medium (2) and the second filter medium (3) have different filter finenesses.

8. Filter according to one of the preceding claims, characterized in that the first filter medium (2) and the second filter medium (3) are formed from a fibrous, non-woven fleece.

9. Filter according to one of the preceding claims, characterized in that the first and second filter media (2, 3) are formed from a pleated filter material.

10. Filter according to one of the preceding claims, characterized in that the first filter medium (2) has a larger pore size or mesh size on its side (12) facing the fluid (6) to be filtered than on its clean side (13).

1 1 . Filter according to one of the preceding claims, characterized in that the filter (1) has a cylindrical shape.

12. Filter according to one of the preceding claims, characterized in that the first filter medium (2) and the second filter medium (3) between a base part (14) and a cover part. (1 5) of the filter (1) are arranged.

13. Filter according to one of the preceding claims, characterized in that a different unfiltrate is introduced to the first filter medium (2) than to the second filter medium (3).

14. Filter according to one of the preceding claims, characterized in that the first filter medium (2) forms a first filter stage and the second filter medium (3) forms a second filter stage for an unfiltrate.

15. Filter according to one of the preceding claims, characterized in that the device (5) for separation and flow management enables an opposite flow direction of filtrate and unfiltrate.