AU2013200072B2

AU2013200072B2 - Sieve

Info

Publication number: AU2013200072B2
Application number: AU2013200072A
Authority: AU
Inventors: Christian Karl
Original assignee: IFE AUFBEREITUNGSTECHNIK GmbH
Current assignee: IFE AUFBEREITUNGSTECHNIK GmbH
Priority date: 2012-01-04
Filing date: 2013-01-04
Publication date: 2014-11-20
Anticipated expiration: 2033-01-04
Also published as: EP2612712B1; SI2612712T1; BR102013000167A2; HRP20161451T1; AT511437B1; HUE032107T2; PL2612712T3; ES2604701T3; AT511437A4; EP2612712A3; EP2612712A2; AU2013200072A1; DK2612712T3

Abstract

A sieve (1) for sieving material moving in a sieving direction (S), the sieve (1) comprising: at least two longitudinally extending plates (2), each plate (2) having a portion orientated substantially perpendicular to the sieving direction (S) and an enlarged portion (4) at an upper edge of the plate (2); at least two curved sections (3) positioned substantially diagonally between at least two adjacent plates (2), each curved section (3) comprises a curved segment (6) having a radius of curvature (R), a lower end and an upper end, wherein tangents at the upper end of at least one of the curved segments (6) defines a sieve plane (7), the sieve plane (7) being parallel to the sieving direction (S), wherein a first distance between the at least two adjacent plates (2) or at least two adjacent curved sections (3) defines a sieve width (M), wherein: a second distance between the sieve plane (7) and a top surface of at least one of the enlarged portions (4) is at least 30% of the sieve width (M), and the radius of curvature (R) of at least one of the curved segments (6) is at least 30% of the sieve width (M). Fig. 1 s 4 5 6 9 Fig.2 4.---

Description

S&F Ref: P058743 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address IFE Aufbereitungstechnik GmbH, of Patertal 20, A-3340, of Applicant: WaidhofenNbbs , Austria Actual Inventor(s): Christian Karl Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: Sieve The following statement is a full description of this invention, including the best method of performing it known to me/us: 5845c(7008412_1) 1 SIEVE FIELD [0001] The invention relates to a sieve with which ribbon-shaped and sheet-like elements, particularly but not exclusively, are separated from the material to be screened, for example during separation of household waste or shredder waste. BACKGROUND [0002] In screening inhomogeneous mixtures of materials, it often happens that particularly elongated, and consequently ribbon-shaped, or sheet-like or plate-like components impede the transport of the material along the screening direction and lead to the formation of material pileups, which upon reaching a critical size, roll over wide areas of the screen, without thereby being screened; these components of the material to be screened also tend to block a considerable proportion of the screen openings for long periods of time, thus further compromising screening quality. The following documents in this technical field deserve to be mentioned: [0003] DE 10 2009 007 823: This screener has as its content the special problem statement of making it easy and feasible to install, to adjust the separation and slope of and to change the separating diaphragms. For this purpose, curved plates are constituted as separating diaphragms, which run substantially diagonally to the screening direction and which in their upper portion, which comes first into contact with the material to be screened, are arranged at least approximately parallel to the plane of the screen, but with their segment lying definitely below the screen plane arranged more steeply. Consequently, the curvature is concave facing the material to be screened. [0004] A screen is known from the applicant's EP 2 196 081, which admittedly is particularly designed to form relatively small mesh openings, but is not limited to that. In this screen, the webs running in vertical planes through the screening direction are provided with recesses surrounded on all sides by web material, into which sections are inserted corresponding to the separating diaphragms of the aforementioned document. These sections can exhibit a curved or bent cross-section; the curvature is thereby formed just as in the aforementioned document. The 2 point of this measure is to arrive at mechanically stable configurations, even at small mesh openings wherein welding of the sections to the webs is no longer possible. [0005] Another screen is known from the applicant's AT 509 855 wherein the webs running in the screening direction exhibit slits on their underside into which sections are inserted having slits on their upper side. The sections in turn are bent or curved, as in the two aforementioned documents, but here a fillet is provided on the upper side of each web which, viewed diagonally to the screening direction, is thicker than the web, whereby preferably the sections have recesses on their upper edges so configured that the fillet lies at least partially below the upper surface of the portions of the sections running parallel or nearly parallel to the plane of the screen. [0006] Moreover, it is known for improving the separation of plate-like elements from a stream of material, in screens wherein the screen facing, viewed in the screening direction, is tiered downward, to place finger-like struts in the area of each tier running above the following screen surface and to cover these to the extent of at least a third of the length of the respective tier. Sheet-like or ribbon-shaped elements are to be thereby prevented from covering the screen openings to a considerable degree and thereby also reducing both the screening quality and the throughput. [0007] The measures mentioned do indeed contribute to improving screening quality and thereby also to raising the achievable throughput, but these improvements have the disadvantages that they are only incremental and still unsatisfactory. OBJECT [0008] It is the object of the present invention to substantially overcome or ameliorate one or more of the disadvantages of the prior art, or at least provide a useful alternative. SUMMARY [0009] In accordance with an aspect of the present invention, there is provided a sieve for sieving material moving in a sieving direction, the sieve comprising: at least two opposing plates including a first plate and a second plate, the first and second plates being separated by a sieve width, the first and second plates each extend (7738108_l)mmi 3 longitudinally in the sieving direction and each having an upper enlarged edge with a top surface; a curved section positioned between the first and second plates, the curved section comprises a curved segment having a radius of curvature and being generally upwardly convex, the curved segment having a lower end and an upper end, wherein a tangent at the upper end of the curved segment defines a sieve plane, the sieve plane being substantially parallel to the sieving direction, and wherein: the sieve plane and one of the top surfaces is separated by a height, the height being at least 30% of the sieve width, and the radius of curvature of the curved segment is at least 30% of the sieve width. [0010] Preferably, the curved section further comprises first and second substantially linear segments, the first substantially linear segment tangentially extends from the upper end of the curved segment and the second substantially linear segment tangentially extends from the lower end of the curved segment. [0011] Preferably, the height is at least 50% of the sieve width. [0012] Preferably, the height is about 100% of the sieve width. [0013] Preferably, the radius of curvature of the curved segment is at least 60% of the sieve width. [0014] Preferably, the radius of curvature of the curved segment is about 100% of the sieve width. [0015] Preferably, a thickness of at least one of the enlarged edges is at least twice a thickness of the first or second plates. [0016] Preferably, a thickness of the enlarged edges is at least three times a thickness of the first or second plates. [0017] Preferably, a thickness of at least one of the enlarged edges is at least four times a thickness of the first or second plates. (7738 108_ )mml 4 [00 18] Preferably, a cross-section of at least one of the enlarged edges is circular in shape. [0019] Preferably, a cross-section of at least one of the enlarged edges is elliptical in shape. [00201] Preferably, a cross-section of at least one of the enlarged edges is semicircular in shape. [0021] Preferably, the sieve direction is substantially inclined to a horizontal plane, and wherein a first angle located between a tangent at the lower end of the curved segment and the horizontal plane is at least 1.5 times a second angle located between the sieve plane and the horizontal plane, [0022] Preferably, the sieve direction is substantially inclined to a horizontal plane, and wherein a first angle located between a tangent at the lower end of the curved segment and the horizontal plane is at least twice a second angle located between the sieve plane and the horizontal plane. [0023] Preferably, the sieve direction is substantially inclined to a horizontal plane, and wherein a first angle located between a tangent at the lower end of the curved segment and the horizontal plane is at least three times a second angle located between the sieve plane and the horizontal plane. [0024] Preferably, the sieve width is between the enlarged edge of the first plate and the enlarged edge of the second plate. [0024a]Preferably, the sieve comprises two said curved sections. [0024b] Preferably, a first of the curved sections is separated from a second of the curved sections by a distance, the distance being substantially similar to the sieve width. [0024c] In accordance with another aspect of the present invention, there is provided a sieve for sieving material moving in a sieving direction, the sieve comprising: at least two opposing plates including a first plate and a second plate, the first and second plates each extend longitudinally in the sieving direction and each having an upper enlarged edge with a top surface; (7738108_1)mml 4a at least two curved sections including a first curved section and a second curved section, the first and second curved sections being separated by a sieve width and positioned between the first and second plates, the first and second curved sections each comprises a curved segment having a radius of curvature and being generally upwardly convex with a lower end and an upper end, wherein a tangent at the upper end of the curved segment of the first or second curved sections defines a sieve plane, the sieve plane being substantially parallel to the sieving direction, and wherein: the sieve plane and one of the top surfaces is separated by a height, the height being at least 30% of the sieve width, and the radius of curvature of the curved segment of the first or second curved sections is at least 30% of the sieve width. [0024d] There is also disclosed herein a screen, consisting of webs running vertically in the screening direction with thickened portions on their upper edges, and of curved sections positioned diagonally between the webs, the tangents whereof at their upper end points define a screen plane, parallel to the screening direction, wherein the free separation between adjoining webs or sections defines the mesh width, characterized in a) that the separation between the screen plane and the upper edge of the thickened portions amounts to at least 30% of the mesh width, preferably at least 50% of the mesh width and especially preferably at least 100% of the mesh width, b) in that the radius of curvature of the curved sections amounts to at least 30% of the mesh width, preferably at least 60% of the mesh width and especially preferably at least 100% of the mesh width, and c) in that optionally present linearly running end portions of the sections each merge into the curved segment without forming a bend. (7738108_1)mml 5 [0025] Preferably, the thickness of the thickened portion or fillet of the web amounts to at least twice, preferably at least three times and especially preferably at least four times the web thickness. [0026] Preferably, the thickened portion or the fillet has preferably a circular or elliptical shape along its upper contour. [0027] Preferably, the angle between the tangents at the lowest point of the curved segment of the section and the vertical is at least 1.5 times, preferably at least twice and especially preferably at least three times the angle between the screen plane and the vertical. [0028] In one preferred embodiment, the upper edges of the webs are configured or equipped with upward rounded cross-sections. Moreover, the sections are curved according to at least a preferred embodiment, with a radius of curvature of at least 30% of the mesh width, preferably at least 60% of the mesh width and especially preferably at least 100% of the mesh width, and exhibit upper end tangents lying in the plane of the screen. Linear rim segments can be connected to one or both ends without bending. BRIEF DESCRIPTION OF THE DRAWINGS [0029] Preferred embodiments of the invention will be described hereinafter, by way of examples only, with reference to the accompanying drawings, wherein: [0030] Fig. 1 shows a screen according to an embodiment of the invention in section view perpendicular to the screen surface and parallel to the screening direction to show the most important size relations; [0031] Fig. 2 shows a schematic view of a plurality of screens positioned one behind the other; and [0032] Fig. 3 to 6 shows cross-sectional views of webs of a screen according to various embodiments of the invention.

6 DETAILED DESCRIPTION [0033] Fig. I shows, purely schematically and without showing the framework, the drive or the bearings of the screen (sieve), a schematic section in the vertical direction parallel to the screening direction (sieving direction) S between two webs (plates/flanges) 2 running parallel to the screening direction, hence through the sections 3 and therewith a side view of the web 2 positioned behind the section. The screen is shown without the customary diagonal arrangement. [0034] The mesh width (sieve width) M of the screen is given by the separation (first distance) of adjoining thickened portions of the webs 2, or by fillets (enlarged portions) 4 (Fig. 6) and adjoining sections 3; these separations are generally of equal size; otherwise, the arithmetic mean of the two separation values is to be used as the mesh width M for the purpose of the invention. Now this mesh width defines various sizes, dimensions and relations of the screen according to an embodiment the invention, in order to be able to attain the initially stated goals: The sections 3 preferably exhibit, in their upper portion, a straight portion or segment (first linear segment) 5, to which a curved portion or segment 6 is joined. According to an embodiment of the invention, the straight segment 5 and the curved segment 6 merge into one another without a bend; if no straight section 5 is provided for, the curved section 6 ends in its upper portion at the end point in a tangent wherein that of the straight segment would run if one were provided. In other words, the upper tangents of the sections 3 all lie in a plane designated in the application as the screen plane (sieve plane) 7 and which, otherwise considered, at least runs parallel to a separately defined screen plane. [0035] The curved portion 6 of the section 3 exhibits at every point a radius of curvature R which, as stated above, amounts to at least 30% (or at least 60%, or at least 100%) of the mesh width M. If the curvature is not constant this applies to each segment, and the individual segments having different curvatures merge into one another without bends. [0036] In the example embodiment shown, the curved segment 6 is joined "downwardly" by a linear segment or portion (second linear segment) 9, by means of which screening can be further improved. If such a linear portion 9 is provided, it is important that it join the curved portion 6 without a bend.

7 [0037] The webs 2, where the sections 3 either are inserted into slits or onto which they are suitably attached, preferably welded, protrude distinctly above the screen plane 7, as defined above; this superelevation (second distance) H amounts to at least 30% of the mesh width M, preferably 50% of the mesh width and it is especially preferable if it is more than 100% of the mesh width M. Moreover, the webs 2 exhibit along their upper edges a thickening, which is accomplished either by plastic distortion of the web material or, as preferred on the grounds of cost, by the application, preferably by welding, of a fillet 4, whereby the fillet, as shown in Fig. 6 exhibits, in the direction perpendicular to the plane of the web 2 and thus in the viewing direction of Fig. 1, a thickness D, which amounts to at least twice, preferably three times, and especially preferably four times the web thickness d. Moreover, as shown in Figs. 3-5, it is preferred that the cross-section of the fillet 4, which is applied to the web 2, along its upper contour, that is from its thickest point on along the perimeter, is made smooth, that is with no bends, hence is made rounded, preferably circular or elliptical. With an elliptical configuration, the transversely elliptical configuration as shown in Fig. 3 is preferred. [0038] Figure 2 shows the arrangement of two (of several) screens (sieves) 1 according to an embodiment of the invention, one after the other, whereby the screen planes 7 running diagonally with the screens are not arranged in alignment with one another, but rather each subsequent screen in the screen direction S lie deeper (mutually parallel in the example embodiment shown) than in the foregoing screen. Here the previously mentioned fingers 8, which are distinctly arranged above the fillets 4, are clearly visible. The fingers can exhibit mutual separations, which correspond to the mesh width; it is not possible, however, to provide these fingers with a greater separation from one another. The angle of the fingers with respect to the screen plane 7 lies between the horizontal and the parallel to the screen plane. The angle as drawn, about (+10%) half as strongly inclined with respect to the vertical as the screen plane, is preferred. [0039] In Fig. 2, two angles are also given, adhering to which (absolute value, hence as a scalar) allows screens according to an embodiment of the invention to be even more effective. This relates to the angle Y joining the screen plane 7 to the horizontal, and the angle X, which joins the tangents of the lower end of the curved segment 6 - and consequently an optionally provided lower linear portion 9 of the sections - to the horizontal. It is preferred that the angle X amount to at least 1.5 times, preferably two times and especially preferably three times the angle Y.

8 [0040] The invention is not limited to the embodiments illustrated and described, but rather can be modified in various ways. It is, as indicated in Fig. 2, possible to combine several screen elements according to the invention, not only in series as shown but also so as to form several screen levels. The mesh width M can vary within wide limits; when used for separating domestic waste, favorable values are 200 mm 20%.

Claims

1. A sieve for sieving material moving in a sieving direction, the sieve comprising: at least two opposing plates including a first plate and a second plate, the first and second plates being separated by a sieve width, the first and second plates each extend longitudinally in the sieving direction and each having an upper enlarged edge with a top surface; a curved section positioned between the first and second plates, the curved section comprises a curved segment having a radius of curvature and being generally upwardly convex, the curved segment having a lower end and an upper end, wherein a tangent at the upper end of the curved segment defines a sieve plane, the sieve plane being substantially parallel to the sieving direction, and wherein: the sieve plane and one of the top surfaces is separated by a height, the height being at least 30% of the sieve width, and the radius of curvature of the curved segment is at least 30% of the sieve width.

2. The sieve according to claim 1, wherein the curved section further comprises first and second substantially linear segments, the first substantially linear segment tangentially extends from the upper end of the curved segment and the second substantially linear segment tangentially extends from the lower end of the curved segment.

3. The sieve according to claim 1, wherein the height is at least 50% of the sieve width.

4. The sieve according to claim 1, wherein the height is about 100% of the sieve width.

5. The sieve according to claim 1, wherein the radius of curvature of the curved segment is at least 60% of the sieve width.

6. The sieve according to claim 1, wherein the radius of curvature of the curved segment is about 100% of the sieve width.

7. The sieve according to claim 1, wherein a thickness of at least one of the enlarged edges is at least twice a thickness of the first or second plates.

8. The sieve according to claim 1, wherein a thickness of the enlarged edges is at least three times a thickness of the first or second plates. 10

9. The sieve according to claim 1, wherein a thickness of at least one of the enlarged edges is at least four times a thickness of the first or second plates.

10. The sieve according to any one of claims I to 9, wherein a cross-section of at least one of the enlarged edges is circular in shape.

11. The sieve according to any one of claims 1 to 9, wherein a cross-section of at least one of the enlarged edges is elliptical in shape.

12. The sieve according to any one of claims I to 9, wherein a cross-section of at least one of the enlarged edges is semicircular in shape.

13. The sieve according to any one of claims 1 to 12, wherein the sieve direction is substantially inclined to a horizontal plane, and wherein a first angle located between a tangent at the lower end of the curved segment and the horizontal plane is at least 1.5 times a second angle located between the sieve plane and the horizontal plane.

14. The sieve according to any one of claims I to 12, wherein the sieve direction is substantially inclined to a horizontal plane, and wherein a first angle located between a tangent at the lower end of the curved segment and the horizontal plane is at least twice a second angle located between the sieve plane and the horizontal plane.

15. The sieve according to any one of claims I to 12, wherein the sieve direction is substantially inclined to a horizontal plane, and wherein a first angle located between a tangent at the lower end of the curved segment and the horizontal plane is at least three times a second angle located between the sieve plane and the horizontal plane.

16. The sieve according to any one of the preceding claims, wherein the sieve width is between the enlarged edge of the first plate and the enlarged edge of the second plate.

17. The sieve according to any one of the preceding claims, comprising two said curved sections. 11

18. The sieve according to claim 17, wherein a first of the curved sections is separated from a second of the curved sections by a distance, the distance being substantially similar to the sieve width.

19. A sieve for sieving material moving in a sieving direction, the sieve comprising: at least two opposing plates including a first plate and a second plate, the first and second plates each extend longitudinally in the sieving direction and each having an upper enlarged edge with a top surface; at least two curved sections including a first curved section and a second curved section, the first and second curved sections being separated by a sieve width and positioned between the first and second plates, the first and second curved sections each comprises a curved segment having a radius of curvature and being generally upwardly convex with a lower end and an upper end, wherein a tangent at the upper end of the curved segment of the first or second curved sections defines a sieve plane, the sieve plane being substantially parallel to the sieving direction, and wherein: the sieve plane and one of the top surfaces is separated by a height, the height being at least 30% of the sieve width, and the radius of curvature of the curved segment of the first or second curved sections is at least 30% of the sieve width.

20. A sieve substantially as hereinbefore described with reference to the accompanying drawings. IFE Aufbereitungstechnik GmbH Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON