The Grit King^® Separator consists of a hollow, cylindrical vessel with a sloping base and a flat cover. The geometry of the interior and the shape and placing of the entry nozzle are such that the flow must follow a prescribed path through the vessel.

Raw liquid is introduced tangentially into the side of the cylinder causing the contents to rotate slowly about the vertical axis. The flow spirals gradually down the perimeter allowing the grit and sand particles to settle out by gravity. This process is aided by the drag forces at the boundary layer on the wall and base of the vessel.

An inverted cone, attached to the centre shaft, is mounted at the bottom of the vessel so that its edge is clear of the sloping base. A grit pot for the separated grit is located under the cone.

The internal components direct the main flow away from the perimeter and back up the middle of the vessel as a broad spiralling column, rotating at a slower velocity than the outer downward flow. In addition, a dip plate is suspended from the underside of a component support frame. This dip plate locates the shear zone, the interface between the outer downward circulation and the inner upward circulation where a marked difference in velocity encourages further grit separation. By the time the flow reaches the top of the vessel, it is virtually free of grit and is discharged to the outlet channel.