Abstract: A rotary drum filter has a plurality of longitudinally extending division grids mounted about the outer circumference of a drum. A plurality of corrugated sheets are provided, with the leading and trailing edges of each sheet mounted to circumferentially adjacent pairs of division grids to define filtrate compartments. An equivalent number of perforated filter plates are also provided. Each filter plate is attached to the top of a corrugated sheet and has a leading edge that is set back from the leading edge of the attached sheet. A seal member is positioned at the leading edge of each corrugated sheet and has a first leg extending between the filter plate and the corrugated sheet. The seal member further includes a second leg which abuts the leading edge of the corrugated sheet so as to block the open ends at the leading edge of the corrugated sheets.