EP2488271A1

EP2488271A1 - Filter device

Info

Publication number: EP2488271A1
Application number: EP10757035A
Authority: EP
Inventors: Ralf Wnuk; Martin Winter
Original assignee: Hydac Process Technology GmbH
Current assignee: Hydac Process Technology GmbH
Priority date: 2009-10-17
Filing date: 2010-09-14
Publication date: 2012-08-22
Also published as: US20120211410A1; RU2012119263A; JP2013508124A; WO2011044977A1; DE102009049712A1; CN102665850B; CN102665850A; KR20120096488A; CA2777614A1; JP5620500B2

Abstract

The invention relates to a filter device, in particular for fluids such as hydraulic oil, lubricating media, processing, surface or sea water, having at least one filter element (3) that has at least one effective filter surface (23), which is suitable for removing contaminants from a media flow crossing the filter surface, wherein an effective filter surface is designed as a flexible filter sock (23) that can be pulled onto a support body (13) of the filter element (3). The invention is characterized in that the filter sock (23), while enlarging the effective filter surface thereof, is designed to be longer in the axial direction of the filter element (3) such that the effective filter surface lies in folds upon pulling the filter sock (23) over the support body (13).

Description

filter means

The invention relates to a filter device, in particular for fluids such as hydraulic oil, lubricating media, process, surface or seawater, with at least one filter element having at least one effective filter surface which is suitable to receive contaminants from a media flow through the filter surface, wherein an effective Filter surface is provided in the form of a filter sock, which is aufziehbar on a support body of the filter element.

In systems and mechanical systems where fluid media are used as equipment, operational safety depends to a great extent on the perfect condition of the media concerned. Especially for higher-value systems, it is therefore necessary, also for economic reasons, to provide suitable filter devices for the media in question, be it gaseous media or fluids, in order to eliminate impurities occurring during operation. When operating fluids in question are loaded with contaminants containing solid particles or colloidal contaminants, special demands must be placed on the efficiency of the filter devices. Conventional filter devices for such applications are therefore structurally complex. This leads to a considerable complexity of relevant overall systems with correspondingly high manufacturing and operating costs. A filter device of the aforementioned type has become known from EP 0 656 223 AI. The known backwash filter, which is backwashed with the dirty liquid to be filtered, has in the filter housing circularly arranged to one another, longitudinally durchströmbare filter candles which are connected to the filter inlet or connectable and for flushing individually or in groups with one end to a with a mud outlet in connection flushing member can be connected. The filter cartridges each consist of a cross-sectionally star-shaped supporting body with six star points, which form at their free ends supporting edges for a filter fabric consisting of a fabric tube. The fabric tube forming the filter medium is pulled over the support body like a sock open on both sides. In filtration operation, the filter cartridges are connected at both ends to the filter inlet.

A filter cartridge with a substantially cylindrical support body for a filter device is known from DE 75 09 253 U. Further, a filter fabric surrounding the support body, a arranged on an end side of the filter cartridge nozzle for the filtrate and a arranged on the other end side and the filter cartridge final lid is provided. The filter fabric is mounted as a prefabricated stocking on the support body. So that the filter fabric can be applied as wrinkle-free as possible to the support body, it is expedient to arrange the rods of the support body slightly conical and form the filter fabric stocking correspondingly conical. The wire, which acts as a screw thread and surrounds the rods, permits sensitive tensioning of the conical stocking by rotating the support body about the longitudinal axis relative to the filter fabric stocking. In view of this, the invention has for its object to provide a filter device of the type mentioned is available, which is characterized by a particularly simple design and high filtration performance and regardless of the requirements to be met.

According to the invention this object is achieved by a filter device having the features of claim 1 in its entirety.

Due to the fact that, according to the characterizing part of claim 1, the filter sock is designed to be longer in enlargement of its effective filter area in the axial direction of the filter element so that the effective filter surface is wrinkled when the filter sock is pulled onto the filter element low design effort and in a very compact design a filter device high efficiency feasible. Through the use of an effective filter surface forming filter sock, which is aufziehbar on a respective support body, also manufacturing operations and assembly operations are very simple, so that a rational, cost-effective production of the respective filter element is made possible. Also, replacement operations of the filter medium are convenient and easy. In addition to the enlargement of the filter surface also result from the pleated shape of the filter sock spacings to the support body.

In a particularly advantageous manner, it can be provided here that the support body has a further filter surface as a further filtration stage and that the respective filter surfaces have mutually different filter finenesses. In a particularly advantageous manner can thereby be in one and the same filter element, combined into a filter combination, realize two filtration stages, so that both a prefiltration and a fine filtration is feasible in a filter element.

When arranged on the outside of the support body filter stocking can at a flow through the thus complemented filter element from outside to inside the filter sock in the sense of a coarse filtration stage lower filter fineness than the other filter surface of the support body, while at a flow through the filter element from the inside to the outside of the filter surface Support body forms the pertinent coarse filtration stage.

With particular advantage, the fineness of the filter surfaces can be tuned so that the pre-filtration stage retains particulate matter in particulate matter, which leads to no significant increase in flow resistance at the lower filtration fineness of the prefiltration and at the same time the risk of premature addition of the fine filtration stage due to the previously eliminated cleaning of the solid particles eliminated. Preferably, the further filter surface of the filter sock is arranged with a predetermined distance to the outside of the support body of the filter element, that in particular in the backwash, in which the media flow occupies a reverse flow direction for filtration operation, contamination from the filter surface are knocked out. Due to the fact that the filter sock forms a loose coating which is not firmly attached to the support body, the flow of the backwashing process can generate movements of the filter sock in the manner of a flapping motion, so that contaminants which have reached the filter surface of the filter sock are shaken out. This operating behavior is favored by the fact that the width dimension of the filter sock is selected such that at least during backwashing a corresponding distance from the filter surface is given.

In a particularly advantageous manner, the filter sock can be exclusively defined as a seamlessly finished filter fabric at least with its two mutually opposite ends at end regions of the filter element, wherein the filter fabric is single-layer or multi-layered and at least partially executed as satin, twill or linen fabric can be.

In this case, the filter sock can be formed from polypropylene, polyester or a lipophilic material, such as polyolefin polyester or copolyester, or from other nonpolar materials which can also be applied as a coating to the filter sock. Furthermore, hydrophilic and / or polar media can also be used here for the filter sock assembly.

In a particularly advantageous manner, the Fi lterelement may have a support body and the effective filter surface forming Spaltsiebrohrfilterelement conical shell shape, which follows the wound filter sock with its contour. Such a split screen tube filter element, which as

Winding body may be formed of metal or plastic, without other components, the structure of a kind of filter candle with thereon mounted filter sock bi lden. With particular advantage, the arrangement can be made such that the effective fi lter surface of the support body, so for example, the split Siebrohrfilterelementes, a filter fineness between 100 to 3,000 // m and that the effective fi lter surface of the filter sock a tuned thereto F lter feinheit between 10th to 1 50 μνη has. Instead of embodiments in which the filter element is flowed through from inside to outside in the filtration operation, the arrangement may also be made in alternative embodiments, that the filter element is arranged in a filter housing such that in filtration operation, the filter element from its outside an internal filter cavity can be flowed through.

In such exemplary embodiments, a prefiltration stage can be implemented in such a way that the filter housing has a swirl space such that the media stream to be filtered is initially guided around the filter element in part in a swirling flow, forming a cyclone. As a result, a particle separation by cyclone effect take place before the medium flows through the filter surface of the filter sock.

The filter device according to the invention, consisting of filter element with filter sock, can be used with particular advantage also in backwash filter devices in which, as shown for example in document WO 98/42426, at least one filter element arrangement can be backwashed by several filter element arrangements. while the other filter element assemblies serve to filter the media stream.

The invention will be explained in more detail below with reference to embodiments illustrated in the drawings. Show it:

Fig. 1 shows a schematically simplified longitudinal section drawn

Filter sock for the embodiments of the filter device to be described;

Fig. 2 is a schematically simplified longitudinal section of the filter element shown separately with a support body, by a forming a filter surface forming Spaltsiebrohrfilterelement is mounted on the filter sock of Figure 1;

a comparison with Figures 1 and 2 drawn on a smaller scale perspective oblique view of the filter element;

a highly schematically simplified and partly longitudinally cut perspective oblique view of a first embodiment of the filter device with filter element inserted therein according to Figures 2 and 3 ..;

an enlarged to illustrate the operation of the first embodiment and not drawn to scale partial section of a wall portion of the Spaltsiebrohrfilterele- mentes of the embodiment;

5 similar, however, more schematically simplified drawn partial representation to illustrate the operation of an alternative embodiment and FIG. 4 similar, greatly simplified schematically and partly longitudinally cut drawn perspective oblique view of a second embodiment of the filter device with filter element inserted therein according to FIG 2 and 3, which can be flowed through from the outside to the inside in the filtration operation.

Below, the invention with reference to FIGS. 1 to 5 is first explained using the example of a filter device in which designated in Fig. 4 by 1 filter housing a designated as a whole with 3 filter element is net, which designed in the manner of a so-called filter candle is and forms two filtration stages in operation. In this example, the filter element 3 has a slightly conically tapered towards the closed end 5 shape. However, the invention is equally feasible with filter elements cylindrical shape. As shown schematically in Fig. 4 is simplified, the filter element 3 in the housing 1 is arranged so that the inner filter cavity 7 is adjacent to a housing opening 9, which at an axial End of the filter housing 1 is located and forms the inflow opening during filtration operation. A lateral housing connection 1 1 forms the outlet for the purified medium in filtration operation. Further details of the embodiment of the filter element 3 to be described here are shown in particular in FIGS. 1 to 3 and 5 can be removed. As can be seen, a split fenestrated filter element 13 in the form of a conical support body surrounds the inner filter cavity 7 with the filter cavity 7 closed at the upper end 15 (Figure 2). The Spaltsiebrohrelement 13 is in the manner known per se in the form of a winding body with turns, which are designated in Fig. 5 with 1 7 and formed by strands of stainless steel or plastic, constructed so that between the turns 1 7 columns 19 are , which form the one effective filter surface, when the element 3 is flowed through in the direction indicated in Fig. 5 flow direction in the filtration process. The width of the column 1 9 is selected so that the effective filter area of the Spaltsiebrohrfilterelementes 1 3 corresponds to a filter fineness, which forms a pre-filtration stage, with a filter fineness, which may be in the range between 100 to 3000 / vm. As can be seen most clearly from FIGS. 2 and 3, the slotted screen tube filter element 13 has at the open end an annular flange 21 which forms an installation in the filter housing 1 in connection to the housing opening 9.

In order to complete the filter element 3, as shown separately and in the complete state in FIG. 3, a filter socket 23 shown separately in FIG. 1 is provided to form a fine filtration stage. This has an open end 25 with a closing ring 27. The filter sock 23 is mounted on this as a coating of the Spaltsiebrohrfilterelementes 13 so that the end ring 27 rests against the annular flange 21 of the Spaltsiebrohrfilterelementes 1 3 and is attached thereto, for example by gluing. The Spaltsiebrohrfilterelement 13 thus forms the support body for the complete filter element 3, wherein at the upper end 29 of the filter sock 23 in the drawing an end cap 31, the filter sock 23 off-. closes, with the associated end of the Spaltsiebrohrfilterelementes 1 3 is connected by a screw 33.

While the filter element 3 is shown in Fig. 3 with a smooth surface forming filter sock 23, preferably, as shown in FIGS. 1, 2 and 4, the length of the filter sock 23 is selected to be greater than the axial length of the Spaltsiebrohrfilterelementes. 1 3. With the filter sock 23 pulled up onto the slotted screen tube filter element 1 3, the sock 23 therefore creases, as shown in the drawing, whereby, as shown, pleats in the manner of a pleating can be formed. Compared with a smooth course of the surface of the sock 23, this results in a very large increase in area, ie an extremely large effective filter area of the effective filter surface formed by the filter sock 23, which serves as a post or fine filtration stage. Due to the formation of wrinkles or pleats, the filter sock 23 also does not contact the surface of the slotted screen tube filter element 1 3 flatly, ie, without the formation of gaps or clearances, which is important for the operating behavior, as will be explained below. For operation as a post or fine filtration stage of the filter sock 23 is preferably gebi Lelted by a seamless filter fabric, which is fixed only at the two ends 25 and 29. In this case, the filter fabric can be formed one or more layers, which may be an atlas, twill or canvas fabric. For a filter fineness, which is substantially higher than that of the Spaltsiebrohrfilterelementes 13, namely, for example in the range between 10 to 80 μιτι liegt, come for the warp threads of the fabric diameter in the range of 50 μνη and for the weft threads diameter in the range of 400 m in question , In addition to common materials for fi lter fabrics such as polypropylene or polyethylene, lipophilic materials such as polyolefin, polyester or copolyester may be provided for the filter sock, as well as other nonpolar materials. Such materials can also be applied to the fabric of the filter sock 23 as an additive in the form of a coating.

In filtration operation, in which the media flow enters through the opening 9 of the filter housing 1 in the inner filter cavity 7 of the filter element 3, the Spaltsiebrohrfilterelement 13, as already mentioned, forms an effective filter surface with the gaps 19 between the windings 1 7, see Fig. 5th In accordance with the filter fineness formed by the spacings of the turns 17, the slotted screen tube filter element 13 serves as a prefilter, which in particular retains solid particles, as indicated in FIG. Corresponding to the higher filter fineness of the effective filter surface formed by the filter sock 23, the fine filtration then takes place, so that contaminants remain in the gap between the slotted screen tube filter element 13 and the folds of the filter sock 23 and the cleaned medium emerges from the filter housing 1 via the connection 1 1.

The filter device according to the invention is particularly well suited for backwashing the filter element 3. For a backwashing process, the flow direction of the medium flow is reversed so that the flushing flow enters via the connection 1 1 in order to flow through the filter element 3 from outside to inside. On the inside of the Spaltsiebrohrfilterelementes 1 3 deposited solid particles are rinsed and rinsed through the housing opening 9. As already mentioned, the distance formed by the folds of the filter stocking 23 or the additional spacing formed by the selection of the dimensioning between the slotted screen pipe filter element 13 and the filter sock 23 is of importance, in particular with regard to the backwashing process. Due to the fact that the filter sock 23 rests loosely on the slotted screen tube filter element 1 3, movements of the filter sock 23, more precisely fluttering movements of the pleated folds, occur as a result of flow influence during the backwashing process. This will shaken off dirt on the filter sock 23 and this cleaned in such a way.

FIGS. 6 and 7 illustrate an alternative example, in which, as indicated in FIG. 6, during filtration operation, the direction of the media flow is directed from outside to inside. As shown in Fig. 6, the support body 13 is designed as a Spaltsiebrohrelement turn with turns 1 7. The slotted sieve tube element forms a fine filtration stage, while the filter sump 23, which is not visible in FIG. 6, forms an upstream prefiltration stage in this flow direction and takes over the coarse filtration.

As shown in FIG. 7, in this exemplary embodiment an optimized flow around the filter element 3 is realized in that the filter housing 1 forms a cyclone in the area of the flow inlet via the connection 1 1. For this purpose, the filter housing 1 at the port 1 1, via which the medium flows tangentially to the housing wall, so conically widened that a swirl space 41 is formed, in which the media stream to be filtered to form the cyclone in a swirling flow around the filament terelement 3 is guided around. The pertinent solution can be backwash by reversing the fluid direction. In particular during the backwashing of the filter sock 23, owing to its folds and / or due to a suitably elastic material structure, it can widen, so that the adhered dirt can be blasted off. In this way, a cleanable surface filter can be achieved.

Claims

Patent claims

1 . Filter device, in particular for fluids such as hydraulic oil, lubricating media, process, surface or seawater, with at least one filter element (3) having at least one effective filter surface (23) adapted to receive contaminants from a media stream passing through the filter surface , wherein an effective filter surface is designed as a flexible filter sock (23) which can be pulled onto a support body (1 3) of the filter element (3), characterized in that the filter sock (23) enlarges its effective filter surface in the axial direction of the filter element ( 3) is designed to be longer so that when pulling the filter sock (23) on the support body (13), the effective filter surface comes to lie in folds.

2. Filter device according to claim 1, characterized in that the support body (13) has a further filter surface (17, 1 9) as a further filtration stage and that the respective filter surfaces (23, 17, 19) have different filter finenesses.

3. Filter device according to claim 2, characterized in that the filter sock (23) on the outside of the support body (13) is arranged and that at a flow through the thus complemented filter element (3) from the outside inward of the filter sock (23) in the sense of Grobfiltrationsstufe has a lower filtration fineness than the other filter surface of the support body (13) and that at a flow through the filter element (1 3) from inside to outside the filter surface of the support body (13) forms the pertinent coarse filtration stage.

4. Fi ltervorrichtung according to claim 2 or 3, characterized in that the filter surface of the filter sock (23) in such a predetermined distance to the outside of the support body (13) of the filter element (3) is arranged, that in a flow through the filter element (3) from outside to inside contaminants are knocked out of the filter surface.

5. Filter device according to one of claims 1 to 4, characterized in that the fi lter stocking (23) as a seamlessly formed filter fabric at least with its two opposite ends (5, 1 5) exclusively fixed to end portions of the support body (1 3) of the filter element is.

6. Filter device according to claim 5, characterized in that the filter fabric one or more layers formed at least partially designed as satin, twill or linen fabric.

7. Filter device according to one of claims 1 to 6, characterized in that the fi lter stocking (23) made of polypropylene, polyester or a lipophilic material, such as polyolefin or copolyester or other non-polar materials is formed, which also as coating on the Filter stocking (23) are applicable.

8. Filter device according to one of claims 2 to 7, characterized in that the filter element (3) has a supporting body and desssen effective filter surface (1 7, 1 9) forming Spaltsiebrohrfi elterelement (1 3) having a conical shell shape, which is the wound up filter sock (23) follows with its contour.

9. Filter device according to one of claims 2 to 8, characterized in that the effective filter surface (1 7, 19) of the support body (1 3) of the filter element (3) has a filter fineness between 100 to 3000 μπ \ and that the effective filter surface of Filter sock (23) has a matched thereto filter fineness between 10 to 1 50 μιτι.

10. Filter device according to one of claims 1 to 9, characterized in that the filter element (3) in a filter housing (1) is arranged such that in the filtration operation, the filter element (3) from its outside to an inner filter cavity (7) can be flowed through.

1 1. Filter device according to claim 10, characterized in that the filter housing (1) such a swirl space (41), that the medium to be filtered medium flow is guided around the filter element (3) at least partially under Bi tion of a cyclone in a swirling flow ,

12. Filter device according to one of claims 1 to 1 1, characterized in that a filter element arrangement, consisting of filter element (3) with filter sock (23), in Rückspülfiltervorrichtungen their

Use is found in which at least one filter element arrangement (3, 23) is backwashable by a plurality of filter element arrangements, while the other filter element arrangements (3, 23) serve to filter the media flow.