Filters for liquids

Claim 1

Apparatus for leaching soluble components from particulate solids by means of a liquid, said apparatus comprising: a container for said solids; a base constituting part of said container and having a generally horizontal generally planar inner face; a plurality of radial ribs on said inner face extending axially into said container and having upper surfaces lying in a plane approximately parallel to and closely spaced from the plane of said inner face, adjacent pairs of ribs defining passageways for radial flow of liquid; a support member positioned centrally on said inner face and extending axially into said container and having a flat upper surface lying in the plane of said upper surfaces of said ribs; a generally planar filter element of thin sheet material supported within said container on said upper surfaces of said ribs and on said upper surface of said support member in spaced parallel relationship to said base; means defining an imperforate, flat surface disposed above said support member and said filter element, said support member, ribs, filter element and said imperforate flat surface cooperatively functioning to provide a toroidal circulation sufficient to (a) significantly reduce compacting of said solids (b) promote formation of a filter cake of said solids (c) significantly reduce clogging of said filter element by said solids, and (d) substantially promote recovery of said soluble components from said particulate solids, when said liquid is poured into said container so as to impinge on said imperforate flat surface, and at least one filtrate drainage opening in said base.