Patent ID: 7416665

Claim:
A filter for filtering a substance suspended in solution, comprising: a filtering tub; a shaft of perforated pipe within said tub; an upper rotary shaft, said shaft of perforated pipe being positioned within said upper rotary shaft; an upper filtering material holder fixed to said upper rotary shaft; and a lower filtering material holder fixed to said shaft of perforated pipe; said upper filtering material holder and said lower filtering material holder, each formed of a plurality of bars extending in the radial direction and being separated from each other in the axial direction by a distance; filtering material being connected to said upper and lower filtering material holders, said filtering material having a good expansion and contraction characteristic, said filtering material hanging on the upper and lower filtering material holders in a loop; said filtering material being wound about said perforated pipe in a helical fashion, said filtering material hanging on said upper and lower filtering material holders, and said filtering material moving along said upper and lower filtering material holders due to a rotation of said upper rotary shaft and upper filtering material holder; whereby said filtering material receives a tension force so as to decrease the size of the pores and implement a desired filtering operation; said filtering material being unwound to implement a reverse washing operation whereby the size of the pores are increased.