Pump especially for waste water containing sludge

摘要

The pump has a toroidal pump housing (2) and at least one beater strip (15,16). The edge (18) of the beater strip and/or the circumferential edge (9) of the screw has indentations and/or protrusions forming an obstruction for pulverizing the solids which have been moved past by the outer rotor wheel part (8). The indentations and/or protrusions are aligned in a row over the length of the edges so that a zig-zag, rake or comb like edge structure is produced. The indentations and/or protrusions can have a triangular, rectangular, semi-circular or irregular shape.