Filtration system

Abstract

A filter for filtering liquid, comprising: a cylindrical housing; and a multiplicity of discs positioned perpendicularly to a height of the cylindrical housing, each of the multiplicity of discs comprised of a first number of cassettes, wherein each cassette is shaped as a truncated sector having a wide end and a narrow end, the cassettes arranged such that a perimeter of the disc is formed by the wide end of the first number of cassettes, and wherein each of the first number of cassettes is connected to a housing at its wide end, and each cassette having an opening along the wide end, wherein during filtration, liquid being filtered flows over the multiplicity of discs towards the perimeter of the multiplicity of discs.

What is claimed is: 
     
         1 . A filter comprising:
 a housing; and   a plurality of connected parallel discs extending within and along a height of the housing, each of the plurality of connected parallel discs comprising:
 a plurality of cassettes each having:
 a wide end, 
 a narrow end, 
 a board with a plurality of supports thereon, 
 an opening extending orthogonally to a plane of the board adjacent to the wide end, 
 a hole in a sidewall of the board adjacent to the wide end, the hole being in fluid communication with the opening, and 
 a filter material wrapped around the board and spaced from the board by the supports; 
 
   wherein the openings of overlapping cassettes of neighboring discs are connected, to define a pipe extending along the height of the housing;   wherein the filter is configured such that a liquid to be filtered flows through the filter material, thereby causing particles in the liquid to be captured by the filter material.   
     
     
         2 . The filter of  claim 1 , wherein the opening extends to a width which is larger than a majority of the width of the wide end of the cassette. 
     
     
         3 . The filter of  claim 1 , wherein the hole extends to a width which is at least a third of a width of the board at the end of the board adjacent the opening. 
     
     
         4 . The filter of  claim 1 , wherein each of the cassettes is shaped as a truncated sector. 
     
     
         5 . The filter of  claim 1 , wherein the cassettes of each of the discs are arranged such that a perimeter the respective disc is formed by the wide ends of its cassettes. 
     
     
         6 . The filter of  claim 1 , wherein:
 each of the cassettes comprises a bore at its wide end; and   the filter further comprises multiple rods, wherein each of the rods is inserted through corresponding bores of overlapping cassettes of neighboring discs.   
     
     
         7 . The filter of  claim 1 , wherein:
 each of the cassettes comprises recesses at opposing sides of the wide end; and   the filter further comprises multiple rails, wherein each of the rails is inserted through corresponding recesses of overlapping cassettes of neighboring discs, and wherein each of the rails is connected to the housing.   
     
     
         8 . The filter of  claim 1 , configured such that the plurality of connected parallel discs remain static during filtration of the liquid and during rinsing of the filter. 
     
     
         9 . The filter of  claim 1 , wherein the filter material comprises a thread wrapped in loops around the board, such that the particles in the liquid are caught between the loops of the wrapped thread. 
     
     
         10 . The filter of  claim 1 , further comprising a rinsing system that comprises a first set of nozzles connected to a first common pipe, each nozzle of the first set located between two adjacent discs of the plurality of connected parallel discs. 
     
     
         11 . The filter of  claim 10 , wherein each of the nozzles is an elongated tube comprising a first aperture in a side wall of the tube near a distal end of the tube, such that fluid flows out of the first aperture at an angle of 45°-135° relative to the length of the tube. 
     
     
         12 . The filter of  claim 11 , wherein each of the elongated tubes further comprises a second aperture in the side wall of the tube, opposite the first aperture. 
     
     
         13 . The filter of  claim 10 , wherein:
 (a) the rinsing system is located within a central area of the housing;   (b) the first common pipe extends along the height of the housing, in an area delimited between the narrow ends of all the cassettes;   (c) the first common pipe is rotatable relative to the housing; and   (d) the first set of nozzles is rotatable relative to the first common pipe.   
     
     
         14 . The filter of  claim 13 , wherein, due to (c) and (d), an end of each of the nozzles is movable over substantially an entire area of the two adjacent discs. 
     
     
         15 . The filter of  claim 14 , wherein, due to (c) and (d), the end of each of the nozzles is movable in spiral motion over the two adjacent discs. 
     
     
         16 . The filter of  claim 10 , wherein:
 the rinsing system further comprises a second set of nozzles connected to a second common pipe, each nozzle of the second set located between two adjacent discs of the plurality of connected parallel discs;   the second common pipe extends along the height of the housing, in the area delimited between the narrow ends of all the cassettes;   the filter further comprises a mechanism configured to, separately:
 rotate the first and second common pipes about a common axis, and 
 rotate each of the first and second common pipes around its own longitudinal axis. 
   
     
     
         17 . The filter of  claim 16 , wherein:
 the first and second common pipes are connected, in parallel, to a joint mount that is disposed perpendicularly to the first and second common pipes;   the joint mount is connected to a pivot; and   the pivot is connected to a chassis of the filter.   
     
     
         18 . The filter of  claim 16 , wherein the common axis is a central axis of the filter. 
     
     
         19 . The filter of  claim 16 , wherein an end of each of the nozzles of the second set is movable over substantially an entire area of the two adjacent discs. 
     
     
         20 . The filter of  claim 19 , wherein the end of each of the nozzles of the second set is movable in spiral motion over the two adjacent discs.