Filter for a treatment apparatus

A filter unit for separation of particulate matter from particulate-laden liquid, the filter unit comprising:

• a chamber defined by an upper axial end wall and an opposing lower axial end wall and a peripheral particle collection wall, the upper and lower axial end walls being spaced by the peripheral particle collection wall, the chamber being rotatable about an axis of rotation so as to impart rotational motion to the particulate-laden liquid;
• an inlet conduit extending within the chamber from or through the upper axial end walls towards the lower axial end wall, the inlet conduit comprising an opening proximal the lower axial end wall forming an inlet for delivering particulate-laden liquid into the chamber;
• an outlet provided in the upper axial end wall for discharging filtered liquid from the chamber;
• and
• a flow path from the inlet to the outlet,
• wherein the flow path includes a radial component from the inlet to the peripheral particle collection wall and an axial component along the peripheral particle collection wall, and
• wherein the filter unit further comprises a guide plate connected to the lower axial end wall, an upper surface of the guide plate forming a guide surface extending radially from the inlet towards the peripheral collection wall.