Patent ID: 8578628

Claim:
A cyclone comprising: an upper cylindrical portion having a longitudinal axis, and a lower frusto-conical portion having an upper wide end and a lower narrow end and a longitudinal axis; said upper cylindrical portion being arranged to open into said upper wide end of said frusto-conical portion, with the longitudinal axes of said upper and lower portions substantially vertical and aligned to form the longitudinal axis of the cyclone; a primary air inlet into the cyclone arranged such that air admitted through said inlet is substantially tangential to the cyclone; an exhaust outlet at or adjacent the end of the cylindrical portion furthest from said frusto-conical portion; a control valve associated with said exhaust outlet and capable of partially or completely shutting off said exhaust outlet; a secondary air inlet associated with the narrow end of said frusto-conical portion and provided with an airflow stabilising device which is adapted to admit a stream of air substantially along or spirally around the longitudinal axis of the cyclone; means for removing processed product from the cyclone; means for moving said airflow stabilising device into and out of the narrow end of the frusto-conical portion during product processing and/or between product processing.