Fluid filter with submerged passages

Claim 1

A filter construction characterized by the substantial elimination of gaskets to prevent bypass leakage of unfiltered fluid comprising a container having an inlet chamber for incoming fluid and having an outlet side spaced from the inlet chamber, said container having a horizontally disposed bottom wall and a vertically disposed side wall, a substantially uniform density mass of granular filter material substantially filling said container and supported on said bottom wall and confined by said side wall, flow guiding wall means embedded in said mass and supported in the container including an inlet area and an outlet area and acting to direct fluid flow through said mass from said inlet chamber to said outlet side and defining a filter zone in said mass consisting of all normal paths of fluid flow through said mass from said inlet area to said outlet area, said filter zone being located centrally within the mass of filter material and being bounded by a thick layer of filter material, said thick layer providing a sealing zone of filter material and all portions of said layer being at least as thick as any portion of the filter zone traversed by fluid flowing from the inlet area to the outlet area, said sealing zone serving to prevent bypassing of unfiltered fluid from the inlet area out of the mass and from the inlet chamber to the outlet side, said flow guiding means comprising horizontally spaced vertically extending parallel perforated wall members providing said inlet area and outlet area and staggered inlet and outlet fluid passages communicating respectively with said inlet chamber and outlet side, and braces between said wall members.