Self-cleaning stationary basket strainer

A self-cleaning stationary basket strainer comprising:

• a vertically disposed housing having an upstanding side wall, an open top and a bottom wall, with an inlet in the side wall for liquid containing particulates adjacent said open top, an outlet in the side wall adjacent said bottom wall for discharge of clean liquid therefrom, a flush discharge opening in said bottom wall, and a cover plate sealingly closing the open top thereof;
• a stationary strainer basket, having a cylindrical foraminous side wall with an inner surface and an open top and bottom, with openings through said cylindrical foraminous side wall for flow of liquid therethrough, disposed in said housing, spaced from said side wall of said housing and disposed below said inlet;
• upper and lower seals between the upstanding side wall of said housing and the side wall of said stationary strainer basket forming a filtrate chamber between said housing and said stationary strainer basket, with said filtrate chamber communicating with said outlet in the side wall of said housing, such that liquid containing particulates entering through said inlet passes into the strainer basket and outwardly through said openings to remove said particulates, and clean liquid in said filtrate chamber is directed through said outlet;
• means for cleaning the inner surface of said strainer basket to remove particulates collected thereon, said means for cleaning being rotatably mounted to move about the inner periphery of said stationary strainer basket, and including a hollow backwash conduit, said hollow backwash conduit having an outer wall defining a chamber, disposed in said stationary strainer basket adjacent the inner surface thereof, said hollow backwash conduit having an elongated passage having two sides through the outer wall thereof facing said inner surface;
• means for moving said means for cleaning about the inner periphery of said stationary strainer basket;
• a scraper blade on one side of said passage of said hollow backwash conduit, positioned to contact said inner surface of the foraminous side wall of said stationary strainer basket;
• an extension member on the other side of said passage of said hollow backwash conduit extending towards said inner surface, said scraper blade and extension member spaced from each other to form a channel therebetween communicating through said passage with the chamber of said hollow backwash conduit;
• means for laterally adjusting at least one of said scraper blade and said extension member relative to each other so as to adjust the width of said channel;
• means for laterally adjusting said scraper blade relative to the inner surface of said strainer basket so as to adjust the pressure of contact of said scraper blade against said inner surface;
• a backwash discharge opening in a wall of said housing;
• a backwash discharge section on said hollow backwash conduit communicating with said backwash discharge opening;
• and
• means for closing and opening said backwash discharge opening.