High flow disc filter

Abstract

A filter device is configured to filter a liquid. The filter device includes a drum sized to receive the liquid and a plurality of filter panels coupled to the drum to define a plurality of discs. The liquid passes through at least a portion of one of the discs. Each filter panel includes a perimeter frame that defines a panel normal flow area and a filter media coupled to the perimeter frame. The filter media may be adapted to include a plurality of pleats.

What is claimed is: 
     
         1 . A filter device configured to filter a liquid, the filter device comprising:
 a drum sized to receive the liquid; and   a plurality of filter panels coupled to the drum to define a plurality of discs, the liquid passing through at least a portion of one of the discs, each filter panel including:
 a perimeter frame defining a panel normal flow area; and 
 a filter media coupled to the perimeter frame. 
   
     
     
         2 . The filter device of  claim 1 , wherein the perimeter frame includes two substantially parallel sides and two sides that extend along lines that are substantially radial with respect to the drum. 
     
     
         3 . The filter device of  claim 1 , wherein the filter media includes a cloth material. 
     
     
         4 . The filter device of  claim 1 , wherein at least one of the plurality of filter panels includes a filter media including a plurality of pleats and at least one reinforcing member configured to maintain the pleated shape of the filter media. 
     
     
         5 . The filter device of  claim 4 , wherein the reinforcing member includes at least one stringer extending across the panel normal flow area, and a plurality of ridge bars extending from the stringer in a direction substantially normal to the stringer. 
     
     
         6 . The filter device of  claim 5 , wherein the stringer includes a plurality of saw tooths that engage the pleats. 
     
     
         7 . The filter device of  claim 5 , wherein the stringer includes a first side that includes saw tooths and a second side that includes saw tooths, and wherein the pleats are sandwiched between the first side and the second side. 
     
     
         8 . The filter device of  claim 5 , wherein the stringer is one of a plurality of stringers, each stringer including saw teeth that engage the pleats. 
     
     
         9 . The filter device of  claim 5 , wherein the pleats define a plurality of peaks and valleys, and wherein each of the ridge bars is positioned adjacent one of the peaks and valleys. 
     
     
         10 . The filter device of  claim 5 , wherein the perimeter frame, the stringer, and the plurality of ridge bars are integrally formed as a single piece around the filter media. 
     
     
         11 . The filter device of  claim 1 , wherein the pleats define a media normal flow area that is measured substantially normal to the pleats and that is substantially greater than the panel normal flow area. 
     
     
         12 . The filter device of  claim 1 , wherein each filter panel is configured to pass a liquid flow therethrough, the liquid flow being in excess of 3 gallons per minute per square foot and at a pressure differential across the filter media in excess of 12 inches of water. 
     
     
         13 . A filter panel configured for use in a filter device that filters a liquid, the filter panel comprising:
 a perimeter frame defining a panel normal flow area.   
     
     
         14 . The filter panel of  claim 13 , wherein the perimeter frame includes two substantially parallel sides and two non-parallel sides. 
     
     
         15 . The filter panel of  claim 13 , wherein the filter media includes a plurality of pleats and the panel flow area is measured normal to the pleats. 
     
     
         16 . The filter panel of  claim 15 , comprising a pleat reinforcing member extending across the panel normal flow area; and a filter media coupled to the perimeter frame and the pleat reinforcing member, the filter media defining a media normal flow area that is substantially greater than the panel normal flow area. 
     
     
         17 . The filter panel of  claim 16 , wherein at least one of the reinforcing members is a stringer that includes a plurality of saw tooths that engage the pleats. 
     
     
         18 . The filter panel of  claim 17 , wherein the stringer includes a first side that includes saw tooths and a second side that includes saw tooths, and wherein the pleats are sandwiched between the first side and the second side. 
     
     
         19 . The filter panel of  claim 17 , wherein the stringer is one of a plurality of stringers, each stringer including saw teeth that engage the pleats. 
     
     
         20 . The filter panel of  claim 16 , wherein the reinforcing members include a ridge bar. 
     
     
         21 . The filter panel of  claim 20 , wherein the ridge bar is one of a plurality of ridge bars. 
     
     
         22 . The filter panel of  claim 21 , wherein the pleats define a plurality of peaks and valleys, and wherein each of the ridge bars is positioned adjacent one of the peaks and valleys. 
     
     
         23 . The filter panel of  claim 16 , wherein the perimeter frame and reinforcing members are integrally formed as a single piece around the filter media. 
     
     
         24 . A filter device configured for use in a filter device that filters a liquid, the filter device comprising:
 a perimeter frame defining a panel normal flow area;   a stringer extending across the panel normal flow area;   a ridge bar extending from the stringer in a direction substantially normal to the stringer; and   a filter media including a plurality of pleats, the filter media coupled to the perimeter frame, the stringer, and the ridge bar, the perimeter frame, the stringer, and the ridge bar being integrally-formed as a single component around the filter media.   
     
     
         25 . The filter device of  claim 24 , wherein the stringer includes a plurality of saw tooths that engage the pleats. 
     
     
         26 . The filter device of  claim 24 , wherein the stringer includes a first side that includes saw tooths and a second side that includes saw tooths, and wherein the pleats are sandwiched between the first side and the second side. 
     
     
         27 . The filter device of  claim 24 , wherein the stringer is one of a plurality of stringers, each stringer including saw teeth that engage the pleats. 
     
     
         28 . The filter device of  claim 27 , wherein the ridge bar is one of a plurality of ridge bars. 
     
     
         29 . The filter device of  claim 28 , wherein the pleats define a plurality of peaks and valleys, and wherein each of the ridge bars is positioned adjacent one of the peaks and valleys. 
     
     
         30 . The filter device of  claim 24 , wherein the perimeter frame includes two substantially parallel sides and two non-parallel sides. 
     
     
         31 . A method of making a filter panel configured to filter a fluid, the method comprising:
 positioning a filter media in an open mold;   closing the open mold to define a plurality of pleats in the filter media; and   injecting a plastic material into the mold, the plastic material flowing around the pleated filter media to define a perimeter frame having a first side and a second side and a plurality of pleat reinforcing members.   
     
     
         32 . The method of  claim 31 , further comprising sandwiching the pleats of the filter media between a plurality of first side saw teeth and a plurality of second side saw teeth defined as part of a portion of the plurality of pleat reinforcing members. 
     
     
         33 . The method of  claim 31 , further comprising embedding a portion of one of a peak and a valley defined by the pleats in one of the pleat reinforcing members. 
     
     
         34 . The method of  claim 31 , wherein the filter media is substantially planar when positioned in the open mold. 
     
     
         35 . A method of filtering a fluid using a plurality of filter panels arranged in a plurality of discs, the method comprising:
 directing a flow of unfiltered fluid between a pair of adjacent discs;   passing the unfiltered fluid through a pleated filter media that at least partially defines each of the panels;   selectively rotating the plurality of discs; and   selectively backwashing the filter panels.   
     
     
         36 . The method of  claim 35 , further comprising supporting the pleated filter media with at least one of a ridge bar and a stringer. 
     
     
         37 . The method of  claim 35 , wherein the fluid includes water. 
     
     
         38 . The method of  claim 35 , further comprising supporting the pleated filter media with a plurality of ridge bars and a plurality of stringers. 
     
     
         39 . The method of  claim 35 , further comprising passing a liquid through the pleated filter media at a rate of at least 3 gallons per minute per square foot (122 liters per minute per square meter). 
     
     
         40 . Facilitating the performance of a method by providing equipment adapted to the performance of the method, the method comprising:
 directing a flow of unfiltered fluid between a pair of adjacent discs;   passing the unfiltered fluid through a pleated filter media that at least partially defines each of the panels;   selectively rotating the plurality of discs; and   selectively backwashing the filter panels.   
     
     
         41 . The method of  claim 40 , further comprising supporting the pleated filter media with at least one of a ridge bar and a stringer. 
     
     
         42 . The method of  claim 40 , wherein the fluid includes water. 
     
     
         43 . The method of  claim 40 , further comprising supporting the pleated filter media with a plurality of ridge bars and a plurality of stringers. 
     
     
         44 . The method of  claim 40 , further comprising passing a liquid through the pleated filter media at a rate of at least 3 gallons per minute per square foot (122 liters per minute per square meter). 
     
     
         45 . A method of installing a filter panel in a disc filter that includes a plurality of filter panels arranged to define a plurality of discs, the method comprising:
 providing a pleated filter panel having a perimeter;   positioning a gasket around the perimeter of the pleated filter panel;   inserting a portion of the pleated filter panel in a panel receiving space;   tilting the pleated filter panel; and   sandwiching a portion of the pleated filter panel between a locking device and a filter support structure to support the pleated filter panel in an operating orientation.   
     
     
         46 . The method of  claim 45 , wherein the panel receiving space includes a slot. 
     
     
         47 . The method of  claim 46 , further comprising the step of defining a seal between the entire perimeter of the pleated filter panel and a panel support structure. 
     
     
         48 . A method of replacing the filter media in a disc filter having a drum and non-pleated filter media coupled to the drum, the method comprising:
 removing the non-pleated filter media from the drum;   coupling a plurality of filter supports to the drum; and   inserting a pleated filter panel in each of the filter supports to define a plurality of discs.   
     
     
         49 . The method of  claim 48 , further comprising molding at least one of the filter supports from a plastic material.