AU5138999A - An improved filtration element - Google Patents

Description

1 4 1 AN IMPROVED FILTRATION ELEMENT This invention relates to an improved filtration element.

This invention has particular but not exclusive application to a filtration element of the type commonly used in disc filter apparatus, and for illustrative purposes reference will be made to such application.

Disc filter apparatus are currently used in the coal mining industry to recover the fines. The filter apparatus typically include a plurality of filtration elements arranged side by side in a circular manner about a central core. Each filtration element consists of a frame which is in the shape of a truncated sector which is enveloped by a stainless steel sheath.

If any portion of the sheath is damaged, then the entire sheath must be removed and replaced with a fresh sheath which can only be achieved by removing the damaged filtration element from the disc filter system. Because the filtration elements are both large and heavy, the removal of filtration elements can be rather cumbersome and time consuming.

~Furthermore, in practice often only a portion of the stainless steel sheath used to cover one side of the filtration element may be damaged and wherein it will be appreciated that the disposal of the entire sheath represents a significant waste of material.

o 20 The present invention aims to alleviate at least one of the above disadvantages and to provide a filtration element which will be reliable and efficient in use.

With the foregoing and other objects in view, this invention in one aspect resides broadly in a filtration element for a disc type filter apparatus, said filtration element including: 2 a first sheet of filtration material; a second sheet of filtration material; a frame in the shape of a truncated sector consisting of a plurality of frame members, said frame being located intermediate said first and second sheets, and attachment means for releasably attaching said first and second sheets to at least one of said frame members.

The material from which the first and second sheets are constructed will be dependent upon the matter to be collected or separated by the filtration apparatus.

For example, for filtering coal fines a mesh like material, such as stainless steel mesh, may be used.

In one embodiment the attachment means may include a plurality of mechanical fasteners, such as a plurality of bolts, which are spaced along the length of the frame members and which extend through aligned apertures formed in both the filtration material and the frame members.

Alternatively a plurality of clamps may be used to clamp the filtration material to the frame members.

ee In yet another embodiment one or more plugs, each locatable in a recess 0...0formed in a frame member, may be used to releasably attach the filtration material to the frame.

20 In one embodiment, the recess may extend along the length of the frame member. However in other embodiments there may be provided a plurality of recesses spaced along the length of the frame member.

In one embodiment the filtration material may include one or more plugs formed either integrally therewith or otherwise attached thereto. For example, the edge portions of the filtration material may be fashioned into a plug. Alternatively, the filtration material, when attached to a frame member, may be sandwiched between the plug and the recess.

In one embodiment the plug may be manufactured from a resilient material and wherein the construction of the plug permits selected portions of same to be deformed. Consequently, the deformed portions of the plug may be retained by compressive forces and/or frictional forces within the recess.

Alternatively the plug may include a portion which is adapted to mechanically engage a portion of the recess. For example, the plug may include a barb which is adapted to engage a protrusion or restriction associated with the recess.

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein: FIG. 1 is schematic side view of a plurality of filtration elements connected to a rotating drum; FIG. 2 is side view of a frame of a filter element constructed in accordance with the present invention, the frame consisting of four frame members; 20 FIG. 3 is a crossed-sectional view of a frame member illustrated in figure 2, and FIG. 4 illustrates the method of releasably attaching sheets of a mesh like material to the frame illustrated in figure 2.

Figure 1 shows schematically a drum 10 of a disc type filtration apparatus.

The drum 10 includes a plurality of individual filtration elements 11, each mounted on a respective rotating arm member 12 which is attached to a shaft 13.

Each filtration element 11 includes a frame 14, as illustrated in figure 2. The frame 14 is shaped like a truncated sector and includes two divergent or radial frame members 15 and 16 which are connected by an arcuate frame member 17 and a central frame member 18. The frame members 15, 16, 17 and 18 are constructed from extruded lengths of aluminium and each include two opposing side flanges 19 separated by an arcuate web portion Each flange 19 includes a channel shaped recess 21 formed therein which extends the length of the frame member. The recess 21 includes a divergent or narrowing throat portion 22, defined by opposing flanges 23 and 24, which leads to a Ssomewhat larger cavity The filtration element 11 also includes two sheets 26 of a stainless steel mesh located on opposite sides of the frame 14. The edge portions 27 of the mesh 26 are a.

releasably secured to the frame 14 by a plug 28 manufactured from an extruded length of a flexible rubber material which has a generally rectangular cross-section and a hollow core 29. The plug also includes two opposing chamfered edges l* a.

20 In use, the sheets 26 of stainless steel mesh are laid over the frame 14 such e.

that they cover same and wherein their edge portions 27 overlie the recesses 21.

The edge portions 27 in turn are forced into the recesses 21 by the insertion therein of the rubber plug 28, as illustrated in figure 4. Removal of the edge portions 27 is inhibited by the retention of the plug in the recesses caused by the deformed portion 32 of the plug having become located behind the flanges 23 and 24 of each recess.

It will be appreciated from reading the foregoing description of the invention that damaged sheets 26 of stainless steel mesh may replaced without removing the filtration element from the drum and wherein there is less wastage of stainless steel mesh.

It will of course be realised be realised that the above has been given only by way of illustrative example of the present invention and that all such modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of this invention as is herein defined in the appended claims.

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Claims (7)

1. A filtration element for a disc type filter apparatus, said filtration element including: a first sheet of filtration material; a second sheet of filtration material; a frame in the shape of a truncated sector consisting of a plurality of frame members, said frame being located intermediate said first and second sheets, and attachment means for releasably attaching said first and second sheets to at least one of said frame members.

2. A filtration element as claimed in claim 1, wherein said attachment means includes a plug that is locatable within a recess formed in one of the aforesaid frame members.

3. A filtration element as claimed in claim 2, wherein said recess extends along the length of said frame member. I* 9

4. A filtration element as claimed in claim 2 or claim 3, wherein said first filtration 20 material or said second filtration material is sandwiched between said plug and said recess.

A filtration element as claimed in any one of claims 2 to 4, wherein said plug is manufactured from a resilient material and wherein the construction of said plug permits selected portions of said plug to be deformed.

6. A filtration element as claimed in claim 5, wherein said recess includes a restriction and wherein said deformed portions of said plug are retained between said restriction.

7. A filtration element substantially as herein before described with reference to the drawings. DATED THIS TWENTY-NINETH DAY OF SEPTEMBER, 1999. MICROLOW PTY LTD by PIZZEYS PATENT TRADE MARK ATTORNEYS