Macerator

Abstract

Macerator comprising a chamber 10, an impeller 20 mounted in the base of the chamber. The impeller 20 has a rotor disc 30. The chamber 10 has a side wall, the side wall has a plurality of cutting apertures in fluid communication with a drain. The periphery of the rotor disc 30 co-operatures with the cutting apertures 50. The cutting apertures 50 extend over an arc of less than 270 degrees around the periphery of the rotor disc 30, the remainder of the circumference around the periphery of the rotor disc does not have any cutting apertures. Some of the plurality of apertures 50 may be joined at the base to define a slot. The apertures 50 may extend over an arc less than 180 degrees, less than 90 degrees, or preferably approximately 60 degrees of the impeller. The apertures may have the same shape, elongate in the vertical direction, or have an arc shape. The base may have a recess, with the impeller set in the recess. A method of operating the macerator is disclosed. Fig. 14