AU707009B2

AU707009B2 - Ore screening panel

Info

Publication number: AU707009B2
Application number: AU89516/98A
Authority: AU
Inventors: Peter Helmut Franz Freissle
Original assignee: Screenex Wire Weaving Manufacturers Pty Ltd
Current assignee: Individual
Priority date: 1996-07-29
Filing date: 1998-10-26
Publication date: 1999-07-01
Anticipated expiration: 2017-07-24
Also published as: AU8951698A

Description

Ore Screening Panel This invention relates to a screening arrangement for screening particulate material such as mineral ores.

Background to the invention Replaceable modular polyurethane panel screening systems of the kind described in Australian Patent 482212 or 517319 have become widely used in a range of mining applications.

Wet screening of ores and dewatering of slurries requires a different style of screen and generally the aperture sizes for the screens are at the lower end of the usual range of aperture sizes used. Blinding of screens is a constant problem and the drive at mines for greater efficiency means that there is always a demand aoo i: for screening panels that enable a greater throughput.

Brief description of the invention To address these needs, the present invention provides an integral moulded polyurethane ore screening panel including a) a plurality of mutually spaced generally parallel elongate screening ribs defining intermediary screening apertures, the screening ribs when the panel is horizontal having operative upper surfaces extending alongitudinally along the ribs and which form the screening surface of the panel, b) transverse supporting ribs which underlie the longitudinal screening ribs so that the screening ribs stand above the transverse ribs to form slots in the screening surface of the panel c) each screening rib being thinner in width than in depth with its lower edge positioned below the upper edge of said transverse ribs 2 d) each screening rib when viewed in transverse cross section having a longitudinal sectional centreline which is substantially perpendicular to said horizontal, at least a major portion of said rib in cross section being symmetrical about said centreline e) and the screening ribs when viewed in transverse cross section tapering downwardly in width from the operative surface to the lower edge of said rib.

The consequence of this construction is that the screening surface appears to have a series of parallel slots running across its surface usually transverse to the direction of flow. Transverse supporting ribs underlie the longitudinal screening ribs so that the screening ribs stand above the transverse ribs to form the slots.

Preferably these slots are parallel to the edges of the screening panel which incorporate the means for securing the panel to the support frame. The panels when arranged on a screening deck can be in any configuration. For wet screening it is preferred to have the slots parallel to the direction of flow of the ore.

For wet screening and dewatering applications this slotted arrangement o increases the open area of the screening surface.

It has been surprisingly found that the tapering of the ribs decreases the incidence of blinding and increases the efficiency of the screening. The most S"important portion to be tapered downwardly is the upper half of the ribs.

Detailed description of the invention The invention is now described with reference to the accompanying drawings in which: figure 1 shows a plan view of a panel in accordance with the invention; figure 2A shows on an enlarged scale a transverse cross-sectional side view of a screening rib of a dewatering panel in accordance with this invention; figure 2B shows on an enlarged scale a transverse cross-sectional side view of another version of a screening rib in accordance with this invention; fi fig ure 3 shows on an enlarged a section on line I1-11 of figure 1.

Reference numeral 10 indicates in general a panel in accordance with the invention. The panel is of moulded synthetic plastics material more specifically polyurethane of a shore hardness in the range of 85-90. The panel is rectangular in shape and has a screening region or zone 12 extending across the top surface. The panel 10 includes a plurality of elongate mutually spaced, transversely extending generally parallel screening ribs 15 extending across the panel 10 and defining intermediary elongate slotted screening aperturesl4.

Each rib 15 when viewed in transverse cross-section has a longitudinal sectional centre line 19 which is substantially perpendicular to a horizontal plane indicated schematically in dotted lines by reference numeral 19.1 on which the panel 10 is laid. The rib 15 has a major portion 17 which in transverse cross-section, is symmetrical about the centre line 19 of the rib In figure 2A the rib 15 has an upper end portion 27 defining an inclined operative surface 21 extending longitudinally along the rib15. The surface 21 is transversely inclined relative to the ribl15. The angle of inclination of the surface 21 is about 50 relative to the horizontal plane 19.1. Each rib 15 defines a leading edge 23 directed upstream of the flow of material to be screened and a trailing *00000 i edge 25 on the downstream side of rib 15. Thus in the fig 2A embodiment the leading edge 23 stands proud of the trailing edge 25 of an adjacent rib The ribs 15 taper in width downwardly from the upper end portions 27 to the opposed ends 29 which are below the top of the support ribsl6. In the drawings the tapering is exaggerated.

The fastening means used to secure the panels to the support frame can be any conventional fastening system as is currently used. In the embodiment illustrated the fastening means is on the edges of the panelbetween which the screening ribs extend. The screening ribs may also run parallel to the edges of the panel carrying the securing means. In installing the panels in a screening deck the panels can be arranged so that the slots are either parallel or transverse to the direction of flow of the ore to be screened. Slots in line with the direction of flow are preferred in dewatering applications.

Any conventional panel fastening means can be utilised with this panel and spigot systems as disclosed in patent 482212 or pin systems as disclosed in !I patent 517319 may be used. These fastening means may be along two parallel sides of the panel or on all four sides.

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1. An integral moulded polyurethane ore screening panel including a) a plurality of mutually spaced generally parallel elongate screening ribs defining intermediary screening apertures, the screening ribs when the panel is horizontal having operative upper surfaces extending longitudinally along the ribs and which form the screening surface of the panel, b) transverse supporting ribs which underlie the longitudinal screening ribs so that the screening ribs stand above the transverse ribs to form slots in the screening surface of the panel.

c) each screening rib being thinner in width than in depth with its lower edge positioned below the upper edge of said transverse ribs d) each screening rib when viewed in transverse cross section having a longitudinal sectional centreline which is substantially perpendicular to said horizontal, at least a major portion of said rib in cross section being symmetrical about said centreline e) and the screening ribs when viewed in transverse cross section tapering downwardly in width from the operative surface to the lower edge of said rib.

2. An ore screening panel as claimed in claim 2 in which the panel is rectangular and has means on two opposed edges of the panels for securing the panel to a support frame, wherein said slots are parallel to said opposed edges.

3. An ore screening deck consisting of a plurality of screening panels, as defined ~in claim 1, secured to a frame of a screening machine wherein the screening ribs are aligned in a direction parallel to the direction of flow of the ore material to be screened.

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