Self-cleaning filter assembly

A method of modifying a filter assembly having a body with a chamber for receiving a filter element and an inlet cavity;

• a filter element attached to said body and positioned within said chamber through which a fluid being filtered must pass, said filter element having an inlet side and an outlet side through which the fluid being filtered passes from said inlet cavity, through said inlet side and then through said outlet side;
• and
• means for cleaning comprising:
• a hollow duct for collecting dislodged particulate matter, said duct mounted to said body and positioned within said inlet cavity adjacent to said inlet side of said filter element, said duct and said filter element being movably mounted relative to each other, wherein said duct includes a slot opening so that said duct is in fluid communication with said inlet cavity;
• an elongated adjustable scraper extending in the longitudinal direction attached to said duct and slidably contacting said filter element inlet side, said scraper substantially equal in length as said slot opening;
• a fluid deflector attached to said duct, said deflector substantially equal in length as said scraper, wherein said deflector is positioned forwardly of said scraper and said slot opening of said duct is positioned between said deflector and said scraper, said deflector having a forwardly leading end positioned in close proximity to said filter element;
• an upper plate attached to said duct adjacent to an upper portion of said scraper and an upper portion of said deflector and a lower plate attached to said duct adjacent to a lower portion of said deflector and a lower portion of said scraper;
• a cleaning chamber defined by said scraper, said deflector, said upper plate, said lower plate and a portion of said duct containing said slot opening, said cleaning chamber in fluid communication with said inlet chamber, whereby when a fluid to be filtered passes from the inlet chamber through the filter element and through the outlet chamber and said duct and filter element move relative to each other, a portion of the fluid is directed from said inlet chamber into said cleaning chamber and said duct, said method comprising the steps of:
• A) attaching to said body a nozzle means for directing cleaning fluid maintained at a pressure greater than the pressure of the fluid being filtered against the inlet side of the filter element for dislodging particulate matter from said inlet side of the filter element, said nozzle positioned within the inlet cavity and adjacent to said inlet side of the filter element and said means for cleaning;
• and
• B) coupling a pressurized cleaning fluid source to said nozzle means.

A fluid filter assembly comprising:

• a filter body defining a chamber, an inlet, an outlet, and a backwash outlet;
• a cylindrical filter element positioned within said chamber and supported by said body through which a fluid entering the inlet must pass to exit the outlet, said filter element having an inlet side and an outlet side, said filter body and the inlet side of said cylindrical filter element defining an inlet cavity;
• means for cleaning the inlet side of the filter element comprising:
• a hollow duct for collecting particulate matter dislodged from said filter element, said duct supported by said body and positioned within said inlet cavity adjacent to said inlet side of said filter element, said duct and said filter element being movable relative to each other, said duct including a slot opening so that said duct is in fluid communication with said inlet cavity;
• a brush having a plurality of bristles attached to said duct and slidably contacting the inlet side of said filter element, said brush substantially equal in length to said slot opening;
• a fluid deflector attached to said duct, said deflector substantially equal in length as said brush, said deflector being positioned forwardly of said brush, said slot opening in said duct being positioned between said deflector and said brush, said deflector having a leading edge positioned in close proximity to said filter element;
• a cleaning chamber defined by said brush, said deflector, and said duct, said cleaning chamber in fluid communication with said inlet cavity;
• whereby when a fluid to be filtered passes from the inlet through the filter element and to the outlet and said duct and said filter element move relative to each other, fluid is directed from said inlet cavity into said cleaning chamber and said duct through which it can be exhausted to said backwash outlet.