Patent ID: 6053441
Filing Date: 2000-04-25
Classification: D21B

Abstract:
In a rotor-stator pair for reducing and defibering a difficult material in a stock where the rotor has a plate-like base that rotates inside the stator to form an attrition interface in the form of a truncated cone between (i) a first zone defined by cutting edges on upright blades of the rotor and a second zone defined by teeth on the outer periphery of the rotor base and (ii) a plurality of alternating cutting bars and flow channels formed on an inner side wall of the stator, a mechanical system that assures attrition of all of the material in the interface by said cutting teeth acting in cooperation with the bars despite the presence of the channels and inter-tooth spacings, comprising,a first structure located on the lower inner face of said stator that deflects the flow of stock through from the first zone to the second zone anda second cooperating structure on said rotor in the spaces between the teeth to block any flow through said spaces which would by-pass the second zone.