Filter for dry cleaning solvent

Claim 1

Filter apparatus comprising: a housing defining a chamber with an imperforate cylindrical peripheral wall and a fluid inlet at one axial end; at least one filter unit comprising a perforate tubular core; an annular, pleated, paper filter element adapted to be removably slid axially onto and around said core, said filter element having first and second axial ends, said filter element comprising walls wherein adjacent walls are joined by an outer, longitudinal edge thereby forming a pleat, adjacent walls of each pleat being sealed together at said axial ends to form a plurality of sealed pockets; and sealing means adjacent to each end of said core, each of said sealing means comprising an end plate with an annular gasket for sealing against the adjacent end of said element adjacent to the inner periphery thereof, at least one of said sealing means being removable from said core to allow replacement of said element and at least one of said sealing means having an outer diameter less than that of said element; and said filter unit being located inside said chamber of said housing around a perforate collection tube therein with said outer, longitudinal edges of said walls of said pleats substantially touching said peripheral wall thereof, and with said one sealing means being adjacent to said inlet whereby fluid can flow axially between and radially outside said pockets of said element and hence through said pleat walls, said pockets and said core to said collection tube.