Abstract: A pump for chopping solid material in a liquid stream having a volute housing, a rotating cutter with at least one blade parallel to a rotational axis of the rotating cutter, an impeller arranged at an outer circumference of the rotating cutter, and a stationary cutter having at least one blade parallel to the rotational axis of the rotating cutter. The stationary cutter is concentric with the rotating cutter, and the stationary cutter, the rotating cutter and the impeller are all at least partially housed within the volute housing. Typically, the rotating cutter has a different number of blades than the stationary cutter. Optionally, the pump, further comprises an inspection cover that is removably attached to the pump, and has an opening large enough to remove the stationary cutter and the rotating cutter from the volute housing.

Abstract: A pump for chopping solid material in a liquid stream having a volute housing, a rotating cutter with at least one blade parallel to a rotational axis of the rotating cutter, an impeller arranged at an outer circumference of the rotating cutter, and a stationary cutter having at least one blade parallel to the rotational axis of the rotating cutter. The stationary cutter is concentric with the rotating cutter, and the stationary cutter, the rotating cutter and the impeller are all at least partially housed within the volute housing. Typically, the rotating cutter has a different number of blades than the stationary cutter. Optionally, the pump, further comprises an inspection cover that is removably attached to the pump, and has an opening large enough to remove the stationary cutter and the rotating cutter from the volute housing.

Abstract: In one aspect, there is provided a wear plate for use in combination with a centrifugal pump and impeller. The wear plate has a wear surface defined by a substantially flat surface, a truncated conic section, and/or a curvilinear solid of revolution formed by revolving an area bounded by a curve around a center axis of the wear plate, wherein a notch or recess is provided. The notch or recess extends in a first direction perpendicular to a predetermined direction of rotation of an impeller and a second direction crossing against a direction of rotation of the impeller.