GB2061124A

GB2061124A - Sieve

Info

Publication number: GB2061124A
Application number: GB8032448A
Authority: GB
Original assignee: Kloeckner Humboldt Deutz AG
Current assignee: Kloeckner Humboldt Deutz AG
Priority date: 1979-10-13
Filing date: 1980-10-08
Publication date: 1981-05-13
Also published as: SE8007164L; IT1188955B; IT8049874A0; DE2941538A1; IT8049874A1; DK430480A; JPS56100660A; FR2467023A1; DD153535A5

Abstract

A sieve, particularly for use in a centrifuge, comprises bars 1 which are connected by resilient elements 5 passing through recesses (e.g. holes or slots) at the ends of the bars. The bars are of a wear-resistant material such as metal ceramics or sintered metal. Resilient elements 5 are of metal, plastics or an elastomeric material. Spacing elements may be provided between adjacent bars. The bars taper downwardly to prevent solids blocking the sieve. <IMAGE>

Description

SPECIFICATION Sieve members The present invention relates to a sieve member such as a sieve or screen base, and more particularly to a sieve base for centrifuges which is assembled from individual hard metal ceramics or sintered metal elements which are highly wear-resistant.

In accordance with German Patent Specification No. 1 043 768, wear-resistant bodies are pressed into a plastics support or adhered to a support and are arranged in rows such that screen openings are formed between them. In the screen bases produced in this way, however, there is the disadvantage that when the screen bases are manufactured the final shape of them has to be taken into account since once the adhesion joint has set it is no longer possible to alter the shape. Therefore, special runs are required in order to produce different shapes and sizes of screen according to this known method and producing these special runs costs more in labour and capital costs and also takes more time.

It is an object of the present invention to simplify the manufacture of sieve members considerably.

According to the present invention there is provided a sieve member comprising a plurality of bar elements made of wear-resistant material, and a plurality of resilient connecting elements which engage in recesses in the bar elements. Sieve members having uniformly shaped elements may there fore be produced in any desired shape or size. Sieve members in accordance with the invention make it possible to prefabricate screen bases of a certain width and length and store them so that the parts desired may be withdrawn from storage and utilized as and when required. The standardization and the resilient connection of the wear-resistant elements not only considerably simplify the manufacture and assembly of these elements, but also save considerably on the cost in terms of labour, time and capital.

In preferred embodiments of the invention, the connecting elements comprise metal, plastics of elastomeric materials in wire, strip, tube or rod form.

These connecting elements are particularly suitable for manufacturing bases for drum-type sieves or screens.

The bar elements may be provided with recesses at their end regions, more particularly at their outer faces. The individual bar elements can then be connected together very rapidly and particularly easily to form screen bases.

In order to be able to set the desired width of the orifices of the screen base in each case, spacing elements may be provided between the wearresistant elements. These spacing elements and/or on the connecting elements. The spacing elements may also be part of a special resilient edge element.

The invention further includes a centrifuge device having a sieve member as described above.

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings of which: Fig. 1 shows a rod-shaped element for use in a sieve member in accordance with the present invention and having openings arranged at the end regions; Fig. 2. shows a section along the line A-B in Fig. 1; Fig. 3. shows a plan view of several elements joined together to form a joint; Fig. 4. shows a rod-shaped element for use in a sieve member in accordance with the invention having recesses arranged on its outer faces; Fig. 5. shows a plan view of two elements for use in a sieve member constructed in accordance with the invention and having intermediate spacing elements; Fig. 6. shows a section along the line C-D in Fig. 5;; Fig. 7. shows a combination of two elements firmly connected together for use in a sieve member in accordance with the invention; and Fig. 8. shows a section along the line E-F in Fig. 7.

As Figures 1 and 2 show, the wear-resistant element 1 is provided with openings 3 at its end regions 2 and is constructed in those regions so as to be rectangular in cross-section. The intermediate region 4 has a downwardly conical and tapering path, as is indicated more particularly in broken lines in Figure 2.

Wires 5 are passed through the openings 3 of the wear-resistant elements 1, as shown in Figure 3, these wires being connecting elements which are resilient to bending, and the elements 1 are simply threaded on to these wires. This means that the screen base can be produced very easily and rapidly with any desired length and width. In addition, the wear-resistant elements 1 can be matched very easily to the respective shape of screen base desired because of the elastic connections made by the wires 5. In practice these wear-resistant elements 1 correspond in their dimensions approximately to the sizes shown in Figures 1 to 3. These elements 1 may therefore be joined together in a particularly advantageous manner to form cylindrical or conical sieve drums of any desired size.The use of these screen or sieve bases manufactured to form sieve drums comprising hard metal ceramics or sintered metal is particularly advantageous because the service life of the screen bases is very long and therefore the screen bases only have to be exchanged or renewed infrequently in comparison to other materials.

In the case of the screen base shown in Figure 3, the respective width 6 of the screen openings corresponds exactly to the width of the element 1. Special spacing elements designed for setting the width of the screen openings may therefore be dispensed with and this is highly advantageous. Moreover, the downwardly tapered portion 4 which can be either conical or stepped is secured in the middle region of the elements 1 so that appropriate solids are unable to clog in the screen openings 6 during operation and can pass freely downwards. Thus prevention of the clogging of the screen openings 6 is ensured.

In the wear-resistant element 7 shown in Figure 4, slit or wedge-shaped recesses 8 are provided on the outer faces and strip-like, rod-shaped or tubular resilient connecting elements 9 are pushed into these recesses 8. As Figures 5 and 6 show the wearresistant elements 7 may have some other crosssectional shape, than the elements 1 shown in Fig ures 1 to 3. Furthermore, spacing elements 11 are provided between the wear-resistant elements 7 in order to set the width 10 of the screen openings.

Both the resilient connecting elements 9 and the spacing elements 11 are part of a resilient plastics mass 12 or are embedded thereinto., the said plastics mass projecting over the sides of the rows of elements 7.

A corrugated intermediate carrier, e.g. a metal strip 13, may be cast at the sides beneath the elements 7 as a further resilient connection. The width of the metal 13 provides the desired spacing in each case from a support framework or from the inner walls of the drum of the centrifuge, while the height may be determined by the strip width alone or in combination with a base member 14 provided on the element 1 or 7. By means of this corrugated arrangement of the metal strip 13 the screen base comprising the individual elements in one plane may very advantageously be bent to form a drum or cylinder of any desired diameter and thus the screen base may be used in any desired centrifuge.

In the above embodiments the resilient connection of the wear-resistant elements make it possible to exactly match the dimensions, shape and width of the screen openings to the respective screen base using uniform elements in very advantageous manner. The width of the screen openings is determined in each case by corresponding insertion of spacing elements between the wear-resistant elements.

These spacing elements may be either adhered to the wear-resistant elements or they may be part of the edge region of the plastics mass 12, or they may be threaded simply on to the flexible connecting elements or connected thereto. In addition the resi lientconnections of the individual elements make it possible to prefabricate screen bases of any desired width and length which may be simply stored and when necessary the required screen bases may be removed in the appropriate size and incorporated into the relevant machine.

As Figures 7 and 8 show, two of the wear-resistant elements shown in Figures 5 and 6 may be joined together or adhered to form one element 15 between which are arranged corresponding spacing elements 16 designed to set the width of the screen openings, and this is carried out in similar manner to that shown in the preceding Figures 5 and 6. As Fig. 8 shows, this embodiment provides a downwardly broadening screen opening which prevents clogging of the screen openings. The arrangement of the wear-resistant elements shown in Figures 7 and 8 also make it possible to manufacture or produce screen bases which have any desired size and have different shapes.

Various modifications may be made to the previ ously.described embodiments. Other different variations are possible in respect of size, shaping and connection of the individual elements to each other as well as in respect of the construction and arrangement of the mounting spacers between the elements. The connecting elements can comprise a material which is resilient under bending forces and/or tension and/or compression as required.

Finally, the wear-resistant metal ceramics or sintered metal elements may be connected to correspond ingly shaped metallic support constructions by adhesion, vulcanization etc., in orderto make the screen base capable of functioning when one of the elements breaks.

Claims

1. A sieve member comprising a plurality of bar elements made of wear-resistant material, and a plurality of resilient connecting elements which engage in recesses in the bar elements.

2. A sieve member according to Claim 1, wherein the bar elements comprise a hard metal ceramics material.

3. A sieve member according to Claim 1, wherein the bar elements comprise a sintered metal material.

4. A sieve member according to any preceding claim, where the connecting elements are resilient under bending forces.

5. A sieve member according to any preceding claim, wherein the connecting elements are resilient under tensioning forces.

6. A sieve member according to any preceding claim, wherein the connecting elements are resilient under compression forces.

7. A sieve member according to any preceding claim, wherein the connecting elements are of a metal material.

8. A sieve member according to any of claims 1 to 6, wherein the connecting elements are of a plastics material.

9. A sieve member according to any of claims 1 two6, wherein the connecting elements are of an elastorneric material.

10. A sieve member according to any preceding claim, wherein each connecting element is in the form of a wire, strip, tube or rod.

11. A sieve member according to any preceding claim, wherein the recesses are at end regions of the bar elements.

12. A sieve member according to claim 11, wherein the recesses are provided in the end faces of the bar elements.

13. A sieve member according to any preceding claim, wherein spacing elements are provided between the bar elements.

14. A sieve member substantially as herein described with reference to the accompanying drawings.

15. A centrifuge device incorporating a sieve member according to any preceding claim.