SCREENING SYSTEM WITH VIBRATION-NODE-ARRANGED VIBRATION SYSTEMS

Abstract

A screening system for screening material, in particular for screening mineral rock, the system having a screen box, with two outer side walls. At least two vibration systems are arranged on each of the two side walls to excite vibration. The two side walls each have at least two vibration nodes in accordance with a bending mode, at least two crossmembers, which connect the two side walls to one another, at least one screen deck, which is supported on the at least two crossmembers. The two vibration systems on each of the side walls are arranged such that each vibration system is arranged in the region of a vibration node of the respective side wall. The disclosure also relates to a method for screening material to be screened, in particular for screening mineral rock, via a screening system of the aforementioned type.

Claims

1.-16. (canceled)

17. A screening system for screening material, the system comprising: a screen box comprising two side walls; at least two vibration systems arranged on each of the two side walls and configured to excite vibration, wherein the two side walls each have at least two vibration nodes in accordance with a bending mode; crossmembers connecting the two side walls; at least one screen deck disposed on the crossmembers; wherein each of the vibration systems on each of the side walls are respectively disposed in a region of one of the at least two vibration nodes of a respective side wall.

18. The screening system of claim 17 wherein each region of each vibration node has a maximum radius from the central point of the vibration node of less than or equal to 20% of the maximum length of the main extent of the respective side wall.

19. The screening system of claim 17 wherein at least one of the vibration systems directly overlaps with a respective vibration node.

20. The screening system of claim 17 wherein at least one of the vibration systems is arranged in such a way in the region of the vibration node of a respective side wall that the magnitude of the region corresponds to a maximum radius from the central point of the vibration node, the magnitude of which is less than or equal to 20%, or less than or equal to 10% of the maximum length of the main extent of the respective side wall (31 or 32), wherein the magnitude of the region of the maximum radius from the central point of the vibration node is anti-proportional to the maximum length of the main extent of the respective side wall (31 or 32).

21. The screening system of claim 17 wherein the screen box has at least two screen decks arranged vertically one above the other and the screen decks are arranged parallel to one another.

22. The screening system of claim 17 wherein the screen box has no more than six screen decks arranged vertically one above the other and the screen decks are arranged parallel to one another.

23. The screening system of claim 17 wherein the side walls are arranged parallel to one another or converge.

24. The screening system of claim 17 wherein the two side walls are arranged in mirror symmetry with respect to a vertical mirror plane extending along a conveying direction.

25. The screening system of claim 17 wherein each vibration system consists of two, three, four or more unbalance drives.

26. The screening system of claim 25 wherein each unbalance drive has a sensor unit for determining a real-time angular position of an unbalance mass portion of each unbalance drive.

27. The screening system of claim 25 further comprising a control system which is connected to the unbalance drives in order to adjust phase offsets of the unbalance drives.

28. The screening system of claim 17 wherein the two vibration systems on each of the side walls are arranged such that each vibration system is arranged in the region of a v-bration node of the first bending mode of the respective side wall.

29. The screening system of claim 17 wherein all the crossmembers are of identical design.

30. The screening system of claim 17 wherein all the crossmembers have a hollow profile.

31. The screening system of claim 17 wherein all the crossmembers are tubes.

32. A method for screening material to be screened, in particular for screening mineral rock, by means of a screening system comprising a screen box comprising two side walls, at least two vibration systems arranged on each of the two side walls and configured to excite vibration, wherein the two side walls each have at least two vibration nodes in accordance with a bending mode, crossmembers connecting the two side walls, at least one screen deck disposed on the crossmembers, wherein each of the vibration systems on each of the side walls are respectively disposed in a region of one of the at least two vibration nodes of a respective side wall, wherein the method comprises: starting the vibration systems; defining a vibration angle for material to be screened by means of a control system of the screening system, for which purpose a phase offset of each vibration system is adjusted electronically; and adapting, when required, the vibration angle for material to be screened by means of the control system, for which purpose the phase offset of each vibration system is adapted electronically.

Description

[0028] Further embodiments of the invention are explained in detail with reference to the following description of an exemplary embodiment and the drawings.

[0029] In the drawings:

[0030] FIG. 1 shows a screening system according to the general prior art in a side view,

[0031] FIG. 2 shows a screening system according to the teaching of the invention in a perspective view,

[0032] FIG. 3 shows the screening system according to FIG. 2 in an alternative perspective view,

[0033] FIG. 4 shows the screening system according to FIGS. 2 and 3 in a perspective plan view,

[0034] FIG. 5 shows a side wall of the screening system according to the invention in a side view illustrating a vibration node of a first bending mode, and

[0035] FIG. 6 shows the vibration nodes of the first bending mode according to FIG. 5 in a simplified illustration.

[0036] FIG. 1 shows a side wall (31 or 32) of a screen box (2) of a screening system (1) according to the prior art for screening mineral rock in a side view. Two vibration systems (4) for exciting vibration are arranged on the illustrated side wall (31 or 32). The illustrated side wall (31 or 32) furthermore has two vibration nodes (S) in accordance with a first bending mode. The illustrated side wall (31 or 32) furthermore comprises crossmembers (5), wherein upper crossmembers (5) each have a round profile, and a lower crossmember (5) has a rectangular profile. The different profiles are provided for reasons of stability, wherein more massive crossmembers (5) are preferably dispensed with for reasons of cost and weight. The crossmembers (5) connect the two side walls (31, 32) to one another. Moreover, a screen deck (6) is mounted on the crossmembers (5). Screened mineral rock falls vertically downward through apertures in the screen deck (6). Mineral rock which is larger than the apertures in the screen deck (6) is moved over the screen deck (6) along a conveying direction (F) by the excitation of the vibration systems (4).

[0037] FIGS. 2, 3 and 4 show an embodiment according to the invention of a screening system (1) for screening mineral rock, wherein this screening system (1) differs from the screening system (1) shown in FIG. 1, particularly in the arrangement of vibration systems (4).

[0038] The screening system (1) shown in FIGS. 2, 3 and 4 has a screen box (2), which comprises two outer side walls (31, 32). The side walls (31, 32) are, in particular, of mirror-symmetrical design, and therefore they do not differ significantly. As illustrated in the present case, the side walls (31, 32) are arranged parallel to one another. In particular, the two side walls (31, 32) are arranged in mirror symmetry with respect to a vertical mirror plane extending along a conveying direction (F).

[0039] As partially and only incompletely illustrated in FIGS. 2 to 5, the two side walls (31, 32) each have two vibration nodes (S) of a first bending mode.

[0040] The two side walls (31, 32) are connected to one another by a multiplicity of crossmembers (5). In the present case, all the crossmembers (5) are of identical design, namely being designed as tubes with a hollow profile.

[0041] It can furthermore be seen in FIGS. 2, 3 and 4 that a screen deck (6) is supported on the crossmembers (5). Screened mineral rock falls vertically downward through apertures in the screen deck (6). Mineral rock which is larger than the apertures in the screen deck (6) is moved over the screen deck (6) along the conveying direction (F) by the excitation of the vibration systems (4).

[0042] Two vibration systems (4) for exciting vibration are arranged on each of the two side walls (31, 32), wherein each vibration system (4) consists of two unbalance drives.

[0043] It is furthermore illustrated that the two respective vibration systems (4) are arranged in such a way on each of the side walls (31, 32) that each vibration system (4) overlaps a vibration node (S) of the respective side wall (31, 32). Stated more precisely, the two vibration systems (4) are arranged on each of the side walls (31, 32) in such a way that each vibration system (4) is arranged in the region of a vibration node (S) of the first bending mode of the respective side wall (31, 32).

[0044] In this context, the word region preferably describes a maximum radius from the central point of the vibration node (S), the magnitude of which is less than or equal to 20%, preferably less than or equal to 10%, particularly preferably 0%, of the maximum length of the main extent of the respective side wall (31 or 32), wherein the magnitude of the region is anti-proportional to a maximum radius from the central point of the vibration node (S), in particular anti-proportional to the maximum length of the main extent of the respective side wall (31 or 32).

[0045] As a particular preference, the unbalance drives of each vibration system (4) are arranged in such a way that each vibration node (S) is positioned between the unbalance drives.

[0046] As a further preference, but not visible in FIGS. 2, 3 and 4, each unbalance drive has an unbalance mass (8). It can furthermore not be seen that each unbalance drive has a sensor unit (7) for determining a real-time angular position of the unbalance mass (8).

[0047] In particular, the screen (1) has a control system, not illustrated here, which is connected to the unbalance drives in order to adjust phase offsets of the unbalance drives.

[0048] FIGS. 5 and 6 show, in a schematic side view, the side wall (31 or 32) of the screening system (1) according to the invention with illustrated vibration nodes (S) of the first bending mode, wherein FIG. 6 is a simplified illustration of FIG. 5. The bending modes are illustrated in simplified form by means of lines. By means of the arrangement of the vibration systems (4) designed as unbalance drives in the region of the vibration nodes (S), the vibration acting on the side walls (31, 32) can be considerably reduced, and therefore the side walls (31, 32) can be of structurally less massive design, thereby resulting in considerable material and hence also cost savings.

[0049] In general, it can be observed that the side view of the screening system according to the prior art shown in FIG. 1 corresponds analogously to the side view of the screening system according to the teaching of the invention shown in FIG. 5, wherein no bending modes are illustrated in FIG. 1.

LIST OF REFERENCE SIGNS

[0050] 1 screening system

[0051] 2 screen box

[0052] 31 side wall

[0053] 32 side wall

[0054] 4 vibration systems

[0055] 5 crossmembers

[0056] 6 screen deck

[0057] 7 sensor unit

[0058] 8 unbalance mass

[0059] F conveying direction

[0060] S vibration node