DE29800455U1 - Gap filter device - Google Patents

Description

Gap filter device

The invention relates to a gap filter device according to the preamble of the main claim. Such a gap filter device is known (US-PS 3 178 023).

In such known gap filter devices, a cylindrical support body is used, which is wound with a filter wire in such a way that a filter coil is created. A small gap between the individual windings of the filter coil allows the medium to be filtered to flow through and thereby holds back the solid particles to be filtered out.

After some time, the filter coil becomes dirty and must be cleaned. To clean it, the filter wire is unwound from the support body. The solid particles adhering to the wire windings of the filter coil are released due to the gravitational and centrifugal forces acting on them. It is also possible to clean it using a special cleaning device that the filter wire runs through.

cleaning system. ,

When the cleaned filter wire is subsequently rewound onto another or the same support body, the filter wire is guided through one or more filter wire guide devices to ensure that the gaps between the individual windings are consistently the same size.

A filter coil pitch can be set as required.

Such filter wire guides are very cumbersome and expensive.

They are also susceptible to interference. &igr;

The invention is based on the object of avoiding these disadvantages and of creating a gap filter device that is inexpensive, has a simple structure and is less susceptible to failure. '

This object is achieved according to the invention by the characterizing features of the main claim. With such a design, it is avoided that the filter wire runs forward in a harmful manner and thus that the filter gap is not enlarged in an undesirable manner. During the winding of the filter coil, the filter wire is supported on the previously wound, adjacent coil winding due to the caster angle A-, and such support leads to an advantageous pre-alignment of the filter wire. This reliably prevents the filter wire from running forward in an undesirable and harmful manner on the support body.

Advantageous further developments of the subject matter of the main claim result from the features of the subclaims as well as from the description and the drawing. For example, according to claim 2 it is advantageous that two equivalent

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tive support bodies are arranged parallel to one another, because with such equipment a largely continuous filter operation is guaranteed. Furthermore, according to claims 4 and 5 it is advantageous that the invention can be used both with support bodies with threads and with support bodies without threads on their outer surfaces.

drawing

Several embodiments of the invention are shown in the drawing and explained in more detail in the following description.
Show it:

Figure 1 shows a first filter coil with filter wire to be wound on,

Figure 2 shows a detail of the construction according to Figure 1 along the line H-II in Figure 1 in section,

Figure 3 shows a variant of the detail according to Figure 2 and

Figure 4 two parallel supporting bodies with the surrounding filter wire.

Description of the embodiments

A gap filter device has at least one filter coil 1, in which a filter wire 2 is wound with tight turns 3 on a cylindrical support body 4. The support body 4 has a vertical support body axis 5 around which it can be rotated. It is hollow and, as can be seen in Figure 2, has a plurality of its outer surface radially

&THgr;5 penetrating holes 7.

For clarity, the "tight" windings 3 in Figures 1 and 2 are not shown as being so tight. Their actual arrangement can be better seen in Figures 3 and 4. Figure 1 shows that the filter wire to be wound is pre-tensioned so that it runs onto the support body 4 without sagging. And this running process takes place at a trailing angle A* of less than 90°, here for example 89° to the support body axis 5. Due to the trailing angle <£ and the filter wire pre-tension, the newly wound winding 3 is always supported on the already wound adjacent winding 3 during winding and only very narrow gaps 12 are created. This measure ensures that there are no large gaps between the individual windings 3 that could be caused by residual dirt on the filter wire 2 or by other irregularities.

The pitch of the filter coil is set according to the present invention so that it corresponds approximately to the width of the filter wire 2. Because the filter wire 2 is guided solely by the already wound, adjacent filter coil winding 3, a special filter wire guide is not required. However, if required, it is possible to use such a guide; it is shown in Figure 1 with the reference number 8. The support body or bodies 4 can be provided with a thread 9 on their outer surface 6, as shown in Figures 1 and 2. The pitch of the thread 9 is slightly larger than the outer diameter of the filter wire 2. When the filter wire 2 is wound, it then runs exactly into the threads of the thread 9, whereby the inventive caster angle <£ ensures that no thread is skipped.

If, however, the support body 4 is smooth and cylindrical on the outside, as shown in Figure 3 on an enlarged scale, the individual windings 3 are fixed by themselves on the outer surface 6. Here, only the caster angle tL· to be maintained ensures that no larger gaps are formed.

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How it works

Figure 4 shows a simplified version of a gap filter device 10. This device uses two identical support bodies 4, which are arranged next to one another with parallel support body axes 5, around which the support bodies 4 rotate. The filter wire to be wound up or unwound runs cleaned onto the left support body 4 to form a filter coil 1 there. The dirty filter wire 2 is unwound from the right filter coil 1. The use of the additional guide 8 can be advantageous here. The right filter coil 1 was previously in operation by filtering out solid particles to be filtered out, hereinafter referred to as dirt 11, from a liquid that was introduced into the support body 4 from above and which flowed outwards via the radial bores 7 and through the narrow gaps 12 between the individual turns 3 of the right filter coil 1. During this flow path, the dirt 11 was stuck to the windings of the filter wire 2. When the filter wire 2 is unwound from the right filter coil 1, the windings 3 of the filter wire 2 are pulled apart and the dirt 11 is "cleaned off", i.e. it detaches from the filter wire 2 and falls downwards into a not shown

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Container. The dirt 11 is removed by gravitational and/or centrifugal forces.

When the left support body 4 has wound the cleaned filter wire 2 into a complete filter coil 1, the left filter coil 1 is ready for operation and the liquid passage can be switched from the right to the left filter coil 1.

When the filter wire 2 is wound onto the support body 3, the caster angle d- according to the invention is maintained in order to form the filter coil 1 uniformly. Maintaining the caster angle A* also applies to a subsequent reversal of the winding direction if the left filter coil 1 is dirty.

Finally, it should be noted that instead of a solid wire, a wire rope can also be used, as shown in Figure 3. Such a wire rope with an open, unsealed surface allows additional flow of the liquid and also holds back the solid particles to be filtered out.

List of reference symbols

170 175 180 185 190

1 Filter coil 2 Filter wire 3 Windings 4 Support body .5 Support body axis 6 Shell surface 7 Drilling 8th guide 9 thread 10 Gap filter device 11 dirt 12 gap

Claims (5)

Protection claims 1. Gap filter device with a support body that can be rotated about a support body axis and with a filter wire that can be wound onto the support body to form a filter spool, characterized in that the filter wire (2) is stretched in a straight line under an appropriate pre-tension during winding and is adjusted to a caster angle (J-) of less than 90° with respect to the support body axis (5). 10 2. Gap filter device according to claim 1, characterized in that two support bodies (4,4) arranged parallel to one another are used, onto which the filter wire <2) can be wound alternately to provide a filter coil (1,1) ready for use. 3. Gap filter device according to claim 1 or 2, characterized in that the filter wire (2) to be wound onto the support body (4) is guided by means of a guide (B). 4. Gap filter device according to one of claims 1-3, characterized in that the supporting body or bodies (4, 4) is (are) provided on the outer surface (6) with a thread (10) which is intended to receive the turns (3) of the filter wire (2) to be wound up. 5. Gap filter device according to one of claims 1-3, characterized in that the supporting body or bodies
<4,4) has or have a smooth outer surface <6) which is intended to receive the turns (3) of the filter wire <2) to be wound.