GB2297701A

GB2297701A - Improved filter sector construction

Info

Publication number: GB2297701A
Application number: GB9602752A
Authority: GB
Inventors: David E Tweet; Nashat N Helmy
Original assignee: Tandem Products Inc
Current assignee: Tandem Products Inc
Priority date: 1995-02-10
Filing date: 1996-02-12
Publication date: 1996-08-14
Also published as: AU4442696A; DE19605075A1; CA2169205A1; ZA961061B; GB9602752D0

Description

-I- 0 2297701

IMPROVED FILTER SECTOR CONSTRUCTION Field of the Invention

The present invention relates generally to filter systems. In particular, the present invention relates to an improved filter sector construction for use in a rotary disc filter structure.

Backcround of the Invention Rotary disc filters are used for removing materials from an aqueous suspension. In one application of the present invention, rotary disc filters are used in filtering processes for removing a mineral ore concentrate from a mineral ore slurry, which is the product of a mineral separation process. The dry ore concentrate obtained from the rotary disc filtering process may be used for pelleting or other processing purposes.

A rotary disc filter structure generally includes a plurality of wedgeshaped filter sectors. Each filter sector is covered by a filter bag. The filter sectors are connected to a central cylindrical drum, and are rotated about the cylindridal drum during disc filter operation.

In operation, the cylindrical drum is rotated counter clockwise such that the filter sectors are selectively immersed and removed from an aqueous suspension or slurry containing the ore from which it is desired to remove the water. Alternately, vacuum or pressurized air is applied to the filter sectors from a vacuum blower or pressurized air source.

When the filter sectors are immersed in the slurry, vacuum is applied through a conduit connected to the filter sectors drawing water through the bag-type filter medium. The ore in the aqueous suspension becomes caked to the exterior surface of the filter bag, while the water filtrate is held between the filter bag and the filter sector. Filtered water is continually drawn through the filter bag until the filter bag becomes substantially caked with ore concentrate.

The filter sector continues to rotate out of the aqueous suspension, exposing the caked ore concentrate to the atmosphere for a drying period. The vacuum is continuously 0 1 0 applied to facilitate rapid drying of the filter bag and caked ore concentrate.

The rotary filter is then positioned above an ore collector bin. Pressurized air is fed through a conduit into each f ilter sector to expand the filter bags and drive the dried ore concentrate from the surface of the filter bag into the collection bin.

The above cycle is continually repeated to collect additional ore concentrate, with a vacuum being applied to each filter sector during immersion into the aqueous suspension of ore and water, subsequent drying of the ore cake on the filter bag, and pressurized air being supplied to each filter sector for removal of the dried ore concentrate into collection bins.

Filter sectors must be constructed to withstand the harsh environment associated with the above process. Fine particles are drawn through the filter bag during the filtering process, subjecting the filter sectors to harsh abrasion and wear. Additionally, filter sectors must withstand repeated exposure to water and subsequent drying.

The repetitive application of a vacuum and subsequent application of pressurized air to the filter sectors subjects the filter sector to severe flex stressing. Present rotary disc filters include a number of filter sectors which are constructed of heavy metallic materials to withstand the severe flex stressing. The heavy metallic filter sectors have been found to be particularly difficult to handle during relatively frequent changes of the filter bag. Other rotary disc filters include filter sector structures constructed of lighter weight materials, which do not have the ability to withstand the flex stressing as effectively as the metal filter sectors.

Filter sectors have also been designed with a combination of metallic and non-metallic material to take advantage of the light weight of moulded plastic, while retaining steel ribs for reinforcement and structural stability. One such invention is disclosed in U.S. Patent No. 4,139,472 to Simonson, which is herein incorporated by reference.

Summarv of the Invention The present invention relates to an improved filter sector construction which may be used in a rotary disc filter structure., In one application, the filter sector is used in a rotary disc filter for removing a mineral ore concentrate from a mineral ore aqueous suspension or slurry.

In one embodiment, the present invention includes a filter sector about which a filter bag is secured. Structural means formed of expanded metal having a plurality of openings are provided for supporting the filter bag. Additionally, means are provided for covering the expanded metal to protect the filter bag.

The structural means may include a plurality of elongated metallic ribs located adjacent the expanded metal and secured to the expanded metal. The expanded metal may be formed in a generally open pattern. Additionally, means may be provided for attaching the filter bag to the filter sector, and means may be provided for securing the filter sector to a rotating filter sy7stem.

In the preferred embodiment, the filter sector includes a pair of generally wedged-shaped structural members formed of expanded metal having a plurality of openings. Means are connected to the structural members for spacing apart the structural members. A non-metallic coating covers the structural members and the means connected to the structural members. In one embodiment, the non-metallic coating is an elastomeric material, and the means for spacing apart the structural members includes a metallic frame.

The pair of generally wedged-shaped structural members are generally planar, each including an arcuate edge, a generally straight edge and a pair of diverging side edges. The filter sector further includes means for reinforcing the structural members, which may include at least one longitudinally extending reinforcement rib secured to the planar structural member extending between the generally straight edge and the arcuate edge.

0 0 The filter sector may further include a means for securing a filter bag to the filter sector, and means for securing the filter sector to a rotary filter system.

The f ilter sector of the present invention provides a light-weight structurally reinforced filter sector which has the ability to withstand the flex stressing present in the mineral ore removal process. Additionally, the filter sector is coated with a non-metallic material for protecting the filter sector from harsh filtering process environments.

In yet another embodiment, the filter sector of the present invention includes a support structure, wherein at least a portion of the support structure is removably attachable. The support structure may include a frame and a pair of structural members, wherein the structural members are removably attachable to the frame.

The support structure may be covered with a non-metallic coating. The structural members may be formed of expanded metal or may be formed of a non-metallic material. In one embodiment, the structural members include a generally planar surface having a plurality of projections extending therefrom.

Means may be provided for removably attaching the structural members to the frame. In the preferred embodiment, the means includes at least one push-through fastener. Alternatively, the means for removably attaching the structural members to the frame include at least.one bolt system.

In the preferred embodiment, each structural member has a plurality of openings extending therethrough, and includes an arcuate edge, a generally straight edge, and a pair of diverging side edges. The frame extends along the arcuate edge and generally straight edge. At least one reinforcement rib may extend between the arcuate edge and the generally straight edge, and at least one reinforcement rib may extend between the side edges.

The filter sector of the present invention is repeatedly exposed to harsh filtering processes, which may damage the filter sector over time. Eventually, the filter sector may have to be replaced. The novel filter sector of the present invention, having removable structural members, provides an efficient and cost-effective method of replacing damaged filter sector structural members, without total filter sector replacement.

Brief Description of the Drawings

The invention will be further described with reference to accompanying drawings where like numbers refer to like parts in several views, and wherein:

Fig. 1 is a perspective view,of the filter sector of the present invention; Fig. 2 is an exploded perspective view in part of the filter sector shown in Fig. 1; Fig. 3 is an enlarged fragmentary perspective view taken from the area encircled at 3 in Fig. 2; Fig. 4 is an exploded perspective view in part of the filter sector shown in Fig. 1; Fig. 5 is an enlarged section taken along line 5-5 in Fig. 4; Fig. 6 is an enlarged fragmentary perspective view of an alternative embodiment of the present invention; Fig. 7 is a fragmentary sectional view taken along line 7-7 of Fig. 6; Fig. 8 is a fragmentary sectional view similar to that of Fig. 7 showing another alternative embodiment of the present invention; Fig. 9 is a fragmentary perspective view of a portion of the frame of the alternative embodiments shown in Figs. 6-8; and Fig. 10 is a fragmentary sectional plan view of another alternative embodiment of the present invention.

Description of the Preferred Embodiments

The present invention relates to an improved filter sector construction for use in a rotary disc filter structure. Rotary disc filters are used, for example, for removing a mineral ore concentrate from a mineral ore aqueous suspension or slurry, which is the product of a mineral separation process. During the filtering process, the disc filter sectors must withstand harsh abrasion and wear, with repeated exposure to water and subsequent drying, causing flex stressing of the filter sectors.

The present filter sector construction is able to withstand the above harsh filtering process environment. The filter sector provides for reduced manufacturing costs and ease in filter bag replacement. Additionally, the present filter sector construction is light-weight, nondamaging to filter bags, and allows for efficient removal of water from the ore slurry, resulting in a very dry residual cake of ore.

Fig. 1 shows a perspective view of a filter sector of the present invention for use with a rotary disc filter system generally at 10. The filter sector 10 is shown located within a f ilter bag 12. The f ilter bag 12 is secured to f ilter sector 10 with restraint rope 14.

Referring to Fig. 2, a detailed perspective view of filter sector 10 is shown. Filter sector 10 generally includes a sector grill 16, a frame 18, reinforcing ribs 20 and collar member 22. Sector grills 16 are generally wedged shaped, and include a plurality of openings 24. Sector grills 16 generally include an inner edge 26, an outer edge 28, and side edges 30 and 32. In one embodiment, the inner edge 26 is straight, and the outer edge 28 is generally arcuate shaped. The side edges 30 and 32 diverge between inner edge 26 and outer edge 28.

The surface of sector grills 16 is generally planar, and includes a plurality of openings 24 extending therethrough. In the preferred embodiment, the sector grill 16 is formed of expanded metal, which may be easily manufactured in various configurations while providing the structural support to the filter sector 10 and filter bag 12, and allowing fluid to pass therethrough. In the preferred embodiment, the sector grills 16 are formed of an expanded metal which is aluminum. The expanded metal construction results in filter sectors which are light- weight for efficient removal /replacement of the filter sector within a rotary filter system.

0 1 Referring to Figs. 2 and 3, a pair of sector grills 16 are located within frame 18. Frame 18 is secured to the outer edge 28 and side edges 30 of sector grills 16.

In the preferred embodiment, the frame 18 is a metallic frame which is formed of a flat bar 36, and rods 38. The flat bar 36 is located between the edges of sector grills 16, spacing apart the sector grills 16. Flat bar 36 is secured to sector grills by methods known in the art, such as welding. Two rods 38 are welded to the outside of flat bar 36, to form a groove 40 between the rods 38.

A plurality of reinforcement ribs 20 are located between the sector grills 16 for structural reinforcement of the filter sector 10. The reinforcing ribs 20 are sized similarly to the frame 18 flat bar 36. The reinforcing ribs 20 are formed of a generally flat bar which aids in uniform spacing apart of sector grills 16. The reinforcing ribs 20 are equally spaced within filter sector 10, and extend longitudinally from inner edge 26, to outer edge 28. The reinforcing ribs 20 are welded to the sector grills 16 and the frame 18 at the outer edge 28.

As shown in Figs. 2 and 3, the filter sector 10 is coated with a nonmetallic coating 44. In general, all metallic surfaces, projections and edges are evenly coated with the nonmetallic coating 44. The f ilm sector 10 may be coated by a known process, such as dipping the film sector 10 in a nonmetallic coating bath or through a spray process where the nonmetallic coating 44 is sprayed onto the film sector 10.

The non-metallic coating 44 is a soft, resilient coating which protects film sector 10 during the harsh ore removal process. Additionally, the coating 44 protects the filter bag 12 from being damaged due to contact with the metallic sector grills 16 and frame 18. In the preferred embodiment, nonmetallic coating 44 is an elastomeric coating.

Collar member 22 is secured to the filter sector 10. Collar member 22 generally includes a tubular extension 50, shoulders 52, and scapula 54. The scapula 54 is connected to the tubular extension 50 through shoulders 52.

0 0.0 1. 0 0 In a preferred embodiment, collar member 22 is formed of a non-metallic elastomeric material. Alternatively, it is recognized that collar member 22 may also be formed of a metallic material and then preferably coated with a nonmetallic coating 44. Collar member 22 is secured to filter sector 10 by mechanical means, such as bolt mechanism 58 extending through holes 60. The inner edge 26 of filter sector 10 is inserted into the collar member 22 with scapulas 54 extending over the planar sides of sector grills 16.

The collar member 22 tubular extension 50 provides for connection of the filter sector 10 to a rotary filter system (not shown). The filter sector 10 is in communication with the rotary filter system, since passages 62 defined by sector grill 16 and reinforcing ribs 20 are in direct communication with the tubular extension 50.

Fig. 1 shows filter bag 12 secured about filter sector 10. Fig. 4 is a detailed perspective view of filter bag 12. Filter bag 12 is formed of a screen filter medium 70 and generally includes a yoke portion 72, a body 74, and a VELCRO fastener system 76.

The filter bag 12 is shaped generally similar to filter sector 10. The filter bag 12 includes a neck opening 78 at the yoke 72, and a bottom opening indicated at 80. The filter bag 12 sides are formed by securing the screen filter medium 70 together as indicated at seams 82.

Filter sector 10 is located within filter bag 12 by first placing the filter bag 12 over the filter sector 12. The yoke 72 extends over the collar member 22, with tubular extension 50 extending up through the neck opening 78. Referring to Fig. 5, VELCRO fastener system 76 secures the bottom of filter bag 12 about the filter sector 10 outer edge 28.

Referring to Fig. 1, Fig. 4, and Fig. 5, filter bag 12 is secured to filter sector 10 using restraint rope 14. Af ter f ilter sector 10 is located within f ilter bag 12, restraint rope 14 is positioned around the filter bag 12 as indicated in Figs. 4 and 5. Restraint rope 14 is securely tightened about f ilter bag 12 and f ilter sector 10 within groove 40.The tightened restraint rope 14 is then tied around collar member 22 and tubular extension So using knots 84 for secure retention of filter bag 12 around filter sector 10.

With filter sector 10 located within filter bag 12, the filter sector 10 may be positioned within a rotary filter system for use in an ore filtering process.

In operation, the present filter sector 10 invention is located within a rotary filter system used in an ore filtering process. A plurality of filter sectors 10 are located about a cylindrical drum. The cylindrical drum is rotated counterclockwise such that the filter sectors 10 are selectively immersed and removed from an aqueous suspension or slurry containing the ore from which it is desired to remove the water. A vacuum or pressurized air may be alternately applied to the filter sectors 10 through tubular extension 50, from a vacuum blower or pressurized air source (not shown).

When the filter sectors 10 are immersed in the slurry, a vacuum is applied through a conduit connected to the filter sectors iO, tubular extension 50, drawing water through the filter bag 12 and planar sector grills 16. Filter water is drawn in through filter bag 12, through the openings 24 in the sector grill 16, through passages 16, and up through tubular extension 50.

The ore in the aqueous suspension becomes caked to the exterior surface of the filter bag 12, while the water filtrate is held between the filter bag 12 and the filter sector 10 and within the filter sector 12. Filtered water is continually drawn through the filter bag 12 until the filter bag 12 becomes substantially caked with ore concentrate.

The filter sector 10 continues to rotate out of the aqueous suspension or slurry, exposing the caked ore concentrate to the atmosphere for a drying period. Vacuum continues to be applied through the tubular extension 50 to facilitate rapid drying of the filter bag 12 and caked ore concentrate.

As the filter sector 10 rotates out of the aqueous suspension or slurry, the water filtrate flows from the arcuate outer edge 28 to the inner edge 26. As the vacuum is continuously applied through tubular extension 50, the water filtrate exits the filter sector 10 through collar member 22 tubular extension 50. The sector grills 16 support filter bag 12, and include a plurality of openings 24 along the sector grill 16 surface such that a substantial portion of filter bag 12 screen filter medium 70 is exposed to the vacuum facilitating rapid drying of the filter bag 12 and caked ore concentrate.

The rotary filter including filter sectors 10 are positioned above an ore collector bin (not shown). Pressurized air is fed through tubular extension 50 into each filter sector 10 to expand the filter bags 12 and drive the dried ore concentrate from the surface of the filter bags 12 into the collection bin. The cycle may be repeated for collecting additional ore concentrate as the filter sector 10, with a vacuum being applied to each filter sector 10 during immersion into the aqueous suspension of ore and water, subsequent drying of the ore cake on the f ilter bag 12, and pressurized air being supplied to each filter sector 10 for removal of the dried ore concentrate into collector bins.

The f ilter sectors constructed in accordance with the present invention are able to withstand the harsh environment associated with the above process. Fine particles are drawn through the filter bag 12 during the filtering process, subjecting the filter sectors 10 to harsh abrasion and wear. Additionally, the filter sectors 10 are able to withstand repeated exposure to water and subsequent drying.

The repetitive application of a vacuum and compressed air to filter sector 10 subjects the filter sector 10 to severe flex stressing. The expanded metal construction of the present filter sector invention allows filter sector 10 to withstand the severe flex stressing.

Additionally, the entire filter sector 10 assembly is coated with a nonmetallic coating 44, which is preferably elastomeric. The non-metallic coating 44 provides further corrosion resistance to the harsh filtering process. The non- metallic coating 44 covers all metallic members of the filter sector 10, providing protection to the filter bag 12 from any metallic sharp edges.

The expanded metal construction allows for filter sector 10 to be formed of a relatively light weight metallic material, providing for ease of filter bag change or filter sector removal. The generally open sector grills 16 allow for water filtrate to easily enter the filter sector 10, and pass through the passages 62 between the pair of sector grills 16, and subsequently discharge through tubular extension 50 without undue constriction. Alternatively, the filter sector 10 may be open between sector grills 16, without reinforcing ribs 20, to further allow unconstricted movement of water filtrate through the filter sector 10.

In an alternative embodiment, the present invention includes a filter sector having removably mounted sector grills. The rotary filter sector is repeatedly exposed to the harsh ore removal process, damaging the filter sector over time. Ex;entually, the harsh ore removal process effects the structural integrity of the filter sector to the extent that the filter sector must be replaced.

The filter sector of the present invention, having removably mounted sector grills, provides an efficient and cost-effective method of replacing damaged filter sector grills, without total filter sector replacement.

Referring to Fig. 6, an enlarged fra gmentary perspective view of an alternative embodiment of the present invention, having sector grills 16 which are removably mounted, is shown generally at 100. The sector grills 16 are removably mounted to the filter sector 10 frame 18 with fasteners 102. Fasteners 102 secure sector grills 16 to frame 18 by extending through sector grill 16 and frame 18, securely retaining sector grill 16 against frame 18.

Sector grill 16 is replaced by first removing fasteners 102. Next, sector gill 16 is removed and a new sector grill 16 is positioned against frame 18. A fastener 102 is then again -12 pushed through sector grill 16 and frame 18, securely retaining sector grill 16 against frame 18.

Referring to Fig. 7, a fragmentary sectional view taken along line 7-7 of Fig. 6 is shown. In one alternative embodiment, fasteners 102 include non- metallic, push-through fasteners 104. To construct filter sector 10, metallic frame 16 is first coated with a non-metallic coating 44. Similarly, sector grills 16, formed of expanded metal, are separately coated with a non-metallic coating 44. Sector grills 16 are then securely attached to frame 18 with non-metallic, pushthrough fasteners 104. In this embodiment, there are no exposed metallic surfaces, which may be affected by the corrosive ore processing process. Sector grill 16 may be changed out by simply removing fastener 104, replacing sector grill 16, and again securing the new sector grill 16 to frame 18 with a new fastener 104.

Referring to Fig. 8, an alternative embodiment of the removably mounted filter sector system is shown generally at 106. In system 106, the sector grills 16 are removably mounted to frame 18 using fasteners 102, which includes a bolt system 108. Bolt system 108 includes bolts 109, washers 110 and 112, and nut 114 for removably securing sector grill 16 to frame 18.

A preferred embodiment of the frame 18 used in the alternative embodiments shown in Figs. 6-8 is shown generally at 116. The frame 118 edge members are formed of a metallic Uchannel 120. Reinforcing ribs 20 extend between the inner edge 26 (not shown) and the bottom edge 28, and for additional structural support, reinforcing ribs 20 may extend between side edge 30 and side edge 32 (not shown). The reinforcing ribs 20 are secured to frame 18 by known methods, such as welds 122.

Holes 124 are located evenly spaced around U-channel 120. Holes 124 allow the sector grills 16 to be removably mounted to frame 18 using fasteners 102. Metallic sector frame 18 may then be coated with a non-metallic coating, such as an elastomeric coating, to protect the metallic frame from harsh filtering processes.

Yet another alternative embodiment of the present invention is shown generally at 130 in Fig. 10. The filter sector 10 shown in Fig. 10 can be constructed similar to the filter sector disclosed in U.S. Patent No. 4, 139,472 to Simonson, which has been incorporated into this application by reference. In this embodiment, sector grills 16 are generally formed of a non-metallic material and include a plurality of substantially cylindrical projections for supporting the filter bag. The frame 18 is generally formed of a metallic material for structural support. The sector grills 16 may be removably mounted to frame 16 using fasteners 102. In the preferred embodiment shown in Fig. 10, the fastener 102 includes a bolt system 108.

After a period of use, the sector grills 16 often become damaged from the ore removal process and need to be replaced. The removably mounted sector grills 16 of the present invention allow sector grills 16 to be easily removed and replaced in a cost-effective and efficient manner without having to replace the entire filter sector in a rotary filter system.

It will be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, material, and arrangement of parts without exceeding the scope of the invention. For example, it is recognized that the filter sector grills may take on different shapes and sizes, including variously shaped openings within the planar surface, while retaining the novel feature of a filter sector formed of an expanded metal construction including a non-metallic coating. Additionally, it is recognized that the removably mounted filter sector gills of the present invention may take on many forms, and may be mounted to the sector frame by other methods, while retaining the novel removably mounted features of the present invention. Accordingly, the scope of the invention is as defined in the language of the appended claims.

1 0 1 0 00 - -. 6

Claims

What is claimed is:

1. A filter sector about which a filter bag is secured, comprising: a.

b.

means for supporting the filter bag, said supporting means formed of metal having a plurality of openings; and coating means covering the metal supporting means.

2. The filter sector of claim 1, further including a plurality of elongated metallic ribs located adjacent the metal supporting means.

3. The filter sector of claim 1, wherein the metal supporting means defines a generally open pattern.

4. The filter sector of claim 1, further including means for attaching the filter bag to the filter sector.

5. The filter sector of claim 1, further including means for securing the filter sector to a rotating filter system.

6. A filter sector, comprising:

a. a pair of generally wedge-shaped structural members formed of expanded metal having a plurality of openings; means connected to the structural members for spacing apart the structural members; and a nonmetallic coating covering the structural members and the means connected to the structural members.

7. The filter sector of claim 6, wherein the nonmetallic coating is an elastomeric material.

-is- 8. The f ilter sector of claim 6, wherein the means for spacing apart the structural members includes a metallic frame.

9. The filter sector of claim 6, further including means for reinforcing the structural members.

10. The f ilter sector of claim 9, wherein the means f or reinforcing the structural members includes at least one longitudinally extending reinforcement rib secured to the structural member.

11. The filter sector of claim 6, further comprising means for securing a filter bag about the filter sector.

12. The filter of claim 6, wherein the structural members are removably connected to the means for spacing apart the structural members.

13.' A filter sector for use in a rotary disc filter comprising:

a. a pair of generally planar structural members formed of expanded metal, each structural member having a plurality of openings extending therethrough and including an arcuate edge, a generally straight edge, and a pair of diverging side edges; and b. means for spacing apart the structural members, including a metallic frame extending along the arcuate edge and pair of side edges.

14. The filter sector of claim 13, further including a nonmetallic coating covering all metallic members of the filter sector.

is. The f ilter of claim 14, wherein the nonmetallic coating is an elastomeric material.

4h 1 -.. ' 1 40 0 409 16. The filter sector of claim 13, further including reinforcing means extending along the generally planar structural members from the generally straight edge to the arcuate edge for structurally reinforcing the filter sector.

17. The filter sector of claim 13, further comprising means for connecting the filter sector to the rotary disc filter.

18. The filter sector of claim 13, further comprising means for securing a filter bag to the filter sector.

19. A filter sector, comprising: a support structure wherein at least a portion of the support structure is removably attachable.

20. The filter sector of claim 19, further including a nonmetallic coating covering the support structure.

21. The filter sector of claim 19, wherein the support structure includes:

a. a frame; and b. a pair of structural members, wherein the structural members are removably attachable to the frame.

22. The filter sector of claim 21, wherein the frame includes at least one reinforcing member.

23. The filter sector of claim 21, wherein the structural members are formed of expanded metal.

24. The filter sector of claim 21, structural members are nonmetallic.

wherein the 25. The filter sector of claim 21, wherein each structural member includes a generally planar surface having a plurality of projections extending therefrom.

26. The filter sector of claim 21, further including means for removably attaching the structural members to the f rame.

27. The filter sector of claim 26, wherein the means includes at least one bolt system.

28. The filter sector of claim 26, wherein the means includes at least one push-through fastener.

29. The filter sector of claim 21, wherein each structural member has a plurality of openings extending therethrough, and include an arcuate edge, a generally straight edge, and a pair of diverging side edges, and the frame extends along th arcuate edge and generally straight edge.

30. The filter sector of claim 29, further including at least one reinforcement rib extending between the arcuate edge and the generally straight edge, and at least one reinforcement rib extending between the side edges.

31. The filter sector of claim 19, furthering including means for connecting the filter sector to a rotary filter system.

32. The filter sector of claim 19, further including means for securing a filter to the filter sector.