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Title:
RISER FOR A FILTER UNIT FOR HIGHLY VISCOUS FLUIDS, AND FILTER UNIT
Document Type and Number:
WIPO Patent Application WO/2015/004157
Kind Code:
A1
Abstract:
Riser (20) for a filter unit (100) for highly viscous fluids having a plurality of disc filter elements (10) which in each case have at least one centre recess, by way of which they are mounted on the riser (20), at least one flow channel (13) extending in the centre recess from a hollow main body (12) which is wrapped around by the filter medium as far as the riser (20), and the riser (20) having at least one bearing section (22) which has a bearing collar (23) for supporting the disc filter elements (10), and having at least one inner flow channel (21), through which flow can pass axially, and having a receiving section (25) above the bearing section (22), on which receiving section (25) the disc filter elements (10) are stacked, and having a head section (29) which lies above it and to which at least one securing element is to be fastened, wherein at least one axial flow channel (26), in which the flow channels (13) open, is formed in the receiving section of the riser (20) between its outer side and the inner side of the centre recess through free cross-sectional regions.

Inventors:
WÖSTMANN STEFAN (DE)
Application Number:
PCT/EP2014/064651
Publication Date:
January 15, 2015
Filing Date:
July 08, 2014
Export Citation:
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Assignee:
NORDSON HOLDINGS S R L & CO KG (DE)
International Classes:
B29C48/69; B01D29/41
Foreign References:
EP1112771A12001-07-04
US20100264100A12010-10-21
US3581902A1971-06-01
US2770370A1956-11-13
US20100113653A12010-05-06
Attorney, Agent or Firm:
TARVENKORN, Oliver (Münster, DE)
Download PDF:
Claims:
Patent Claims

1 . Riser (20) for a filter unit (100) for highly viscous fluids having a plurality of disc filter elements (10) which in each case have at least one centre recess, by way of which they are mounted on the riser (20), at least one flow channel (13) extending in the centre recess from a hollow main body (12) which is wrapped around by the filter medium as far as the riser (20), and the riser (20):

having at least one bearing section (22) which has a bearing collar (23) for supporting the disc filter elements (10), and

having at least one inner flow channel (21 ), through which flow can pass axially,

having a receiving section (25) above the bearing section (22), on which receiving section (25) the disc filter elements (10) are stacka- ble, and having a head section (29) which lies above it and to which at least one securing element is to be fastened, characterized in that at least one axial flow channel (26), in which the flow channels (13) open, is formed in the receiving section of the riser (20) between its outer side and the inner side of the centre recess through free cross-sectional regions.

2. Riser (20) according to Claim 1 , characterized in that the centre recess is round and is enclosed by a hub (1 1 ) which is adjoined by the filter media of the disc filter elements (10).

3. Riser (20) according to Claim 2, characterized in that the riser (20) has a polygonal cross section in the receiving section (25), the circumcircle diameter of which polygonal cross section corresponds to the hub diameter, the flow channels (26) being formed between the side faces of the riser (20) and the inner wall of the hub (1 1 ).

4. Riser (20) according to one of Claims 1 to 3, characterized in that at least one groove which forms a hollow channel in the flow channel (26) is made in the receiving section (25) on the outer circumference of the riser (20).

5. Riser (20) according to at least one of Claims 1 to 4, characterized in that the flow channel (26) through at least one recess (24) on the bearing collar (23) merges into the inner flow channel (21 ) of the bearing section (22).

6. Filter unit (100) for highly viscous fluids, having a plurality of disc filter elements (20) which in each case have at least one centre recess, by way of which they are mounted on a riser (20), at least one flow channel (13) extending in the hub centre recess from a hollow main body (12) which is wrapped around by the filter medium as far as the riser (20), and the riser (20):

having at least one bearing section (22) which has a bearing collar (23) for supporting the disc filter elements (10), and

having at least one inner flow channel (21 ), through which flow can pass axially,

having a receiving section (25) above the bearing section (22), on which receiving section (25) the disc filter elements (10) are stacked, and having a head section (29) which lies above it and to which at least one securing element is to be fastened, characterized in that at least one axial flow channel (26), in which the flow channels (13) open, is formed in the receiving section of the riser (20) be- tween its outer side and the inner side of the centre recess through free cross-sectional regions.

7. Filter element (100) according to Claim 1 , characterized in that the centre recess is round and is enclosed by a hub (1 1 ) which is adjoined by the filter media of the disc filter elements (10).

8. Filter element (100) according to Claim 6 or 7, characterized in that the hub (1 1 ) has a receiving hole with a polygonal cross section, and in that the riser has a round cross section in the receiving section, the diameter of which round cross section corresponds to the in-circle diameter of the hub hole, the flow channels being formed between the side faces of the polygonal cross section on the inner wall of the hub (1 1 ) and the outer shell of the riser (20) in the receiving section (25).

9. Filter element (100) according to one of Claims 6 to 8, characterized in that, in the receiving section, at least one groove which forms a hollow channel in the flow channel (26) is made on the inner circumference of the hub (1 1 ) and/or on the outer circumference of the riser (20).

10. Filter element (100) according to at least one of Claims 6 to 9, characterized in that the flow channel (26) through at least one recess (24) on the bearing collar (23) merges into the inner flow channel (21 ) of the bearing section (22).

Description:
Riser for a filter unit for highly viscous fluids, and filter unit

The invention relates to a riser for a filter unit for highly viscous fluids with at least one riser and a plurality of disc filter elements according to the preamble of Claim 1 , and to a filter unit having the features of the preamble of Claim 6.

A filter unit of this type is known, for example, from DE 42 12 928 A1 and is usually inserted into a screen cavity of a screen carrier of a filtering apparatus in such a way that fluid which flows into the screen cavity from the outside passes through the filter media of the disc filter elements. In the main body which is spanned by the filter media, the fluid flows in the direction of a centre recess which is arranged, in particular, inside a central, annular hub. Here, the hub has at least one flow channel which can be flowed through from the outer side in an approximately radial direction to the inner side. The individual disc filter elements are stacked on the riser and are sealed among one another. The stack is secured on the riser, with the result that the assembly comprising disc filter elements is sealed towards the outside and a flow is possible only through the filter media to the inner hole of the hubs.

These disc filter elements which have been proven per se require very complicated manufacture of the riser, however, because it has to be drilled through not only centrally, in order to form an inner flow channel, but rather, in particular, the openings in the pipe wall of the hollow section of the riser also have to be arranged exactly in such a way that they coincide with the hole pattern of the openings of the flow channels in the hub. Furthermore, it has to be ensured during assembly that the flow channels of the hubs come into congruence in a positionally correct manner with the flow channels in the riser, or structural measures have to be provided, in order to force the positionally correct positioning. If the riser and disc filter elements are not positioned exactly with respect to one another, the cross sections of the flow paths are at least constricted or even closed completely.

It is an object of the present invention to improve a riser for a filter unit of the type mentioned at the outset, and a filter unit of the type mentioned at the outset, in such a way that the disc filter elements can be stacked on the riser around the centre recess independently of the arrangement of the flow channels and also independently of the height, without the need of an adaptation of the flow paths in the riser for this purpose.

According to the present invention, this object is achieved by both embodiments by virtue of the fact that at least one axial flow channel, into which the flow channel opens, is formed in the receiving section of the riser, that is to say in that region, in which the stacked disc filter elements are to be arranged, between the outer side of the riser and the inner side of the hub. Therefore, according to the present invention, a flow channel which lies on the inside is no longer formed at least in the receiving section of the riser, or at least no longer exclusively a flow channel which lies on the inside. Rather, an axial flow channel which extends over a large part of the receiving section is formed when the disc filter elements are mounted on the riser. Here, a disc filter element is provided, in particular, which has a central hub, that is to say a tubular and, in particular, cylindrical sleeve or else a relatively thick-walled, annular element, the centre recess being provided in the centre and in each case the filter media adjoining from the outside.

It is also conceivable to dispense with a separate hub element if there are, for instance, perforated plates which are so solid and dimensionally stable that they do not require any separate support on the inner edge via a hub element.

According to the invention, the flow channel for axial throughflow of the riser is therefore formed simply by virtue of the fact that the cross-sectional area of the riser in the receiving section does not coincide with the cross section of the inner recess in the hub, so that free cross-sectional areas result in between and therefore form cavities, through which flow can pass axially. In the case of incident flow of the disc filter elements from the outside, the fluid therefore exits as usual through the hub of the disc filter elements to the inside, but, in contrast to the prior art, then does not pass through radial holes into the interior of a hollow region within the riser, but rather flows downwards along the outer side of the riser.

The flow resistance at the transition between the disc filter element and the riser is therefore no longer determined by the position and size of openings in the riser. As long as the flow channels of the hub open only somehow in the flow channels which are formed between the hub and the riser outer side, there is a connection, without it being necessary for the hole patterns to be adapted exactly to one another.

In contrast to the prior art, it is also possible according to the invention, in particular, to provide different spacings of the flow channels in the hubs in the axial direction, by disc filter elements with flatter or higher hubs being used, even in combination with one another.

According to one preferred embodiment, the flow channels are formed by virtue of the fact that the hub has a round receiving hole and the riser has a non-round, in particular polygonal cross section in its receiving section, the circumcircle diameter of which polygonal cross section corresponds to the internal diameter of the hub. As a result, the position of the disc filter elements is fixed in a positively locking manner in the receiving section by means of the hub. Axial flow channels are then formed above the receiving section in the non-covered regions of the cross section.

The receiving section is preferably triangular, with the result that a total of three axial flow channels are then formed on the riser as flow channels.

The said flow channels preferably end in each case in at least one recess on the bearing shoulder in that bearing section of the riser which lies at the lower end, which recesses are in turn connected to an inner flow channel in the bearing section. The said recesses extend in the radial direction on the bearing shoulder to the outside only to such an extent that, outside them, there is still a sufficient overlap section of the hub of the first disc filter element, which hub bears against the bearing shoulder, with the result that there is a sealing action between the bearing shoulder and the hub.

As an alternative, the flow channels can also end at a little axial spacing from the bearing shoulder and then merge through radial holes into the flow channel which lies on the inside. In addition to a polygonal cross-sectional shape of the riser, it is also possible to form the flow channels by way of axial grooves in a receiving section of the riser, which receiving section is otherwise round. As viewed in cross section, the homogeneous arrangement of grooves distributed over the circumference again leads to a quasi- polygonal cross section, face sections of more pronounced roundness remaining, however, at the corners, which face sections make improved guidance of the hub which is in contact and likewise improved sealing of the flow channels among one another possible, in order to avoid cross-flows and to force directed axial flow through the filter unit.

Finally, it is possible in a kinematic reversal to provide the inner walls of the hubs with grooves or to configure them to be non-round, in particular polygonal, whereas the associated receiving section of the riser remains round on its outer side.

Additional hollow channels can be formed on the bottom of the flow channels, which additional hollow channels increase the cross section, through which flow can pass, or the hollow channels themselves form the flow channels, through which flow can pass axially, on the riser.

Finally, grooves and/or non-round cross sections can be provided both on the hub and the riser in the receiving section, in order to form flow channels between them.

In the following text, the invention will be explained in greater detail with reference to the exemplary embodiment which is shown in the drawing, in which, in detail:

Fig. 1 shows a perspective view of a mounted filter unit,

Fig. 2 shows a perspective view of a riser,

Fig. 3 shows a detail of the lower region of the riser in a perspective view,

Fig. 4 shows the riser from below,

Fig. 5 shows a filter unit in a diagrammatic sectional view from the side, and

Fig. 6 shows a radial section through the filter unit along the line VI-VI in

Figure 5. Fig. 1 shows a finished filter unit 100, to be precise from the underside, on which a bearing section 22 of a riser 20 protrudes out of a stack of disc filter elements 10. The bearing section 22 is intended to insert the filter unit 100 into a hole in a screen carrier and to bring it into connection with the flow channels of a filtering apparatus.

The disc filter elements 10 are supported in a bearing shoulder 23 of the riser 20, which bearing shoulder 23 has an enlarged diameter with respect to the bearing section 22 and a receiving section 25. In the region of the bearing section 22, the riser 20 is of hollow configuration with an inner flow channel 21 .

At the non-visible end of the filter unit, the stack of disc filter elements 10 is secured by way of a baffle plate which is guided in the head section 29 of the riser 20 and which makes it possible to prestress the assembly of disc filters 10 in the axial direction against the bearing shoulder 23, in order to bring about the sealing action.

Fig. 2 shows the riser 20 without the disc filter elements. Here, the division into three pieces can be seen clearly:

the lower bearing section 22 with the inner flow channel 21 ,

the receiving section 25 which is intended to receive the stack of disc filter elements 10, and

the head section 29 at the other end, which head section 29 provides, for example, threaded holes and/or key faces, in order for it to be possible to mount the filter element 100 and to attach securing elements, by way of which the stack of disc filter elements 10 is to be pressed onto the bearing shoulder 23.

In Fig. 2, in the receiving section 25, a considerable reduction of the cross section is to be noted in comparison with the head section 29 which has the same circumcircle diameter as the receiving section 25. There is a triangular cross section in the receiving section 25 and, in addition, grooves 27 which extend axially are formed in the side faces of the riser which is triangular there.

As Fig. 3 shows, in particular, the flow channels 26 which are formed between the riser 20 and the hub 1 1 open into recesses 24 on the inner side of a bearing shoulder 23. Here, the recesses 24 are connected to the inner flow channel 21 in the bearing section 22. Fig. 4 shows the riser 20 from below with a view into the inner flow channel 21 of the bearing section 22 and its bearing shoulder 23. The inner flow channel 21 branches into three recesses 24, at which in each case one of the flow channels 26 opens.

Fig. 5 shows a lateral section through the filter unit 100. A stack of disc filter elements 10, of which only two are shown here for the sake of clarity, bears tightly against one another and is attached to the bearing shoulder 23. Sealing rings which are inserted in each case and are composed, for example, of a non-ferrous metal seal among one another between the hubs 1 1 of the disc filter elements 10 and also with respect to the bearing shoulder 23. The flow path is therefore possible only through the respective disc filter element 10, to be precise through the cavity 12 which is spanned by the filter medium and the flow channel 13 which extends in the radial direction through the hub 1 1. The flow channel 13 of the disc filter element 10 opens into the flow channel 26 which forms the flow channel, through which flow can pass in the axial direction, of the filter element 100 as far as the recess 24 in the bearing shoulder 23. There, the fluid can enter into the inner flow channel 21 and then flows out at the lower end of the riser 20.

The reverse flow direction is likewise possible, the incident flow from the outside being advantageous in the case of high pressures and highly viscous fluids, in order to prevent widening and possible tearing of the filter medium.

Figure 6 is a radial sectional view through the filter unit 100, to be precise along the line VI-VI in Figure 5. Of the disc filter elements 10, only the hub 1 1 which lies on the inside with the flow channels 13 and part of the filter media which adjoin the hub 1 1 are visible here.

In the centre recess within the hub 1 1 , the triangular contour of the riser 20 and the free cross-sectional regions including the grooves 27 which form the flow channels 26 which lie on the outside can be seen.