Filtering panel and method of making the same

Patent metadata

Field	Value
Publication number	US-10857491-B2
Application number	US-201515316379-A
Country	US
Kind code	B2
Filing date	Jun 5, 2015
Priority date	Jun 5, 2014
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

The present invention relates to a filtering panel (100) for a disk filter and a disk filter for water purification, comprising a metal filter cloth (16, 116) such as a stainless steel filter cloth, pre-tensioned in both warp and weft directions and fastened to a frame (10, 110) comprising a peripheral portion (11, 111), which is integral with an inner grillwork (12) and which divides the inner area of the peripheral portion (11, 111) into fields (15, 115). The frame (10, 110) comprises a plastic material reinforced with glass fibers or carbon fibres such as polypropylene loaded with fibreglass in an amount of at least 20 weight percent. Each field of the grillwork (12, 112) has an area not exceeding 10% of the inner area of the peripheral portion (11, 111). The pre-tensioning of the filter cloth (16, 116) in both directions is from at least 20% of the yield stress of the cloth (16, 116). Further the present invention relates to a disk filter comprising said filtering panels (100) and method of making said filtering panel (100).

First claim

The invention claimed is:

1. A filtering panel for a disk filter for water purification, the filtering panel comprising:
a metal filter cloth; and
a frame comprising a peripheral portion, the frame consisting of a plastic material loaded with fibers of glass or carbon, the frame being integral with an inner grillwork which divides an inner area of the frame into a plurality of fields, each field of the plurality of fields having an area not exceeding 10% of the inner area of the frame, the inner grillwork including longitudinal strips and transverse strips, the peripheral portion comprising a ridge on at least a portion of an inner edge region of the frame configured to support bonding of the metal filter cloth to the frame, and a portion of the metal filter cloth being embedded in a plastic material of the ridge along the inner edge region of the peripheral portion so as to be irreversibly fastened to the frame;
wherein the metal filter cloth is pre-tensioned in both warp and weft directions to at least 20% of a yield stress of the metal filter cloth and fastened to the frame.

2. The filtering panel according to claim 1 ,
wherein the metal filter cloth is pre-tensioned in both directions to a range of from 20% to 30% of the yield stress of the metal filter cloth.

3. The filtering panel according to one of claim 1 or claim 2 , wherein the plastic material is selected from polypropylene (PP), polyethylene (PE), polyphenylene oxide (PPO), a blend of PPO and styrene, polyphenylene sulfide (PPS) and polyvinyl chloride (PVC) and mixtures thereof.

4. The filtering panel according to claim 3 ,
wherein the plastic material is polypropylene and the plastic material is loaded with fiberglass in an amount from at least 20% to 40% weight percent.

5. The filtering panel according to claim 1 or claim 2 , wherein each of the fields has an area not exceeding 5% of the inner area of the frame.

6. The filtering panel according to claim 1 or claim 2 , wherein a peripheral portion of the frame comprises an L-shaped cross section having a flow parallel leg and a flow transverse leg substantially normal to the flow parallel leg.

7. The filtering panel according to claim 6 , wherein the flow transverse leg comprises at least one of an inner edge portion for attaching the metal filter cloth to the frame and a circumferential outer edge portion for attaching the metal filter cloth to the frame.

8. The filtering panel according to claim 1 or claim 2 , wherein the metal filter cloth comprises stainless steel and wherein the stainless steel of the metal filter cloth is AISI 316L.

9. The filtering panel according to claim 1 or claim 2 , wherein the metal filter cloth has a pore size ranging from 5 to 100 micron.

10. The filtering panel according to claim 1 , wherein the metal filter cloth is pre-tensioned in both warp and weft directions to at least 30% of a yield stress of the filter cloth and fastened to the frame.

11. The filtering panel according to claim 1 , wherein a peripheral portion of the frame comprises a polytetrafluoroethylene (PTFE) layer.

12. The filtering panel according to claim 1 , wherein the metal filter cloth is pre-tensioned in both warp and weft directions to a yield stress of between about 12 N/mm and about 17 N/mm.

13. The filtering panel according to claim 1 , wherein the metal filter cloth comprises at least one bonding seam configured to be fixedly attached to the inner edge region of the peripheral portion of the frame.

14. The filtering panel according to claim 1 , wherein a largest dimension of the plurality of fields is less than twice a smallest dimension of the plurality of fields.

15. The filtering panel according to claim 1 , wherein the metal filter cloth comprises a metal selected from the group consisting of stainless steel, bronze, copper, brass, titanium, nickel and alloys thereof.

16. The filtering panel according to claim 1 , wherein the transverse strips have a greater thickness parallel to a direction of water flow through the filtering panel than the longitudinal strips.

17. A disk filter comprising:
a drum having a central longitudinal axis, rotatably arranged around the central longitudinal axis and adapted to receive a liquid to be filtered, and
at least one disk-shaped filter member on an outside of the drum extending outwards in a transverse direction of the drum and including releasably secured filtering panels,
wherein each of the filtering panels is a filtering panel as claimed in claim 1 or claim 2 .

18. The disk filter according to claim 17 , wherein the filtering panels are arranged to perform inside-out filtration of the liquid to be filtered.

19. The disk filter according to claim 17 , wherein the liquid to be filtered comprises municipal wastewater.

20. The disk filter according to claim 17 , wherein the liquid to be filtered comprises at least one of industrial wastewater, process water, and potable water.

Assignees

• Evoqua Water Tech Llc

Inventors

• Braschi Marco
• Negrini Roberto

Classifications

• B01D33/21 Primary

  with hollow filtering discs transversely mounted on a hollow rotary shaft · CPC title

• B01D2201/127

  with means for keeping the spacing between the pleats · CPC title

• B01D33/23 Primary

  Construction of discs or component sectors thereof · CPC title

• B07B1/4618

  Manufacturing of screening surfaces · CPC title

• B01D33/067

  Construction of the filtering drums, e.g. mounting or sealing arrangements · CPC title