Disc filter for liquids

A disc filter body for a filter of the counter-current flow cleaning type, comprising:

• (a) a series of coaxial annular shaped solid filter elements, said elements having a hydrodynamic lenticular shaped cross-section, and each element having three circumferentially spaced alveoli axially aligned on opposite sides of the elements said filter elements forming a central cylindrical flow channel extending axially along the length of said filter body;
• (b) resilient yieldable spacer elements arranged locally in said alveoli between said filter elements to provide filtering spaces between the filter elements and provide a cylindrical shaped filter body, each spacer element having a central channel in alignment with the channels of adjacent spacer elements, capable of being opened or substantially closed by varying the pressure exerted on said spacer elements;
• and
• (c) means for varying the distance between the adjacent filter elements by varying the pressure exerted axially on the filter and spacer elements and thereby varying the distance between the filter elements in response to said pressure variation for changing the filter body from a filtering mode to a cleaning mode of operation.

A disc type filter assembly of the counter-current flow cleaning type, comprising:

• (a) a chamber having inlet and outlet connections for alternately introducing and removing a liquid being filtered and a washing liquid;
• (b) a disc filter body mounted within said chamber, said body comprising a series of adjacent solid ring-shaped filter elements having a hydrodynamic lenticular cross-section, each separated from the adjacent elements by resilient spacer elements, said spacer elements being located between adjacent filter element rings in alveoli located on opposite sides of the filter elements rings said filter elements forming a central cylindrical flow channel extending axially along the length of said filter body, each of said spacer elements having a central channel in alignment with the channels of adjacent spacer elements, capable of being open or substantially closed by varying the pressure exerted on said spacer elements;
• and
• (c) means for varying the spacing between said filter elements by varying the force exerted axially on said resilient spacer elements, whereby the spacing between adjacent filter elements is uniformly increased during the cleaning mode operation of the filter assembly.

A method for filtering fluids using a disc type counter-current filter body, comprising:

• (a) applying axial pressure to a filter body comprising multiple adjacent ring-shaped filter elements having a hydrodynamic lenticular cross-section, each separated by resilient spacer elements and providing narrow spaces between the filter elements during a filtering mode said filter elements forming a central cylindrical flow channel extending axially along the length of said filter body, each of said spacer elements having a central channel in alignment with the channels of adjacent spacer elements, capable of being open or substantially closed by varying the pressure exerted on said spacer elements;
• (b) passing a fluid through the narrow spaces between the multiple adjacent filter elements in said filter body and retaining particles on the filtering elements;
• (c) releasing the axial pressure on said filter body, thereby permitting the resilient spacer elements to expand and increase the spacing between the adjacent filter elements during a cleaning mode;
• and
• (d) flowing a fluid through said wider spaces in direction opposite to the filtering mode flow direction to wash the collected particles from the filter body.