Rotary piston pump, for fluids containing solids, has oval casing with meshing rotors that have concave contour and acute leading and trailing edges and has cutting filter in inlet or outlet

摘要

The pump has an oval casing (10) with an inlet (11) and an outlet (12) and a pair of meshing rotors (2,2') with parallel rotation axes (29,29'), which each have one or two displacement blades (21,21'). The radial outer blade parts (3,3') have an outer contour that matches the inner contour of the pump casing and have a concave contour area (24,24') between acute leading and trailing edges (34,34',35,35'). A cutting filter (5) is arranged in the inlet or the outlet that co-operates with the leading acute edges of the displacement blades to form a unit to break up the solids.