Crushing or grinding element for drum refiners

Abstract

A grinding element for a drum refiner for the crushing or grinding of fibrous material. The drum refiner includes an engine driven rotor having a generally horizontal rotor axis and at least one material feed. A rotor jacket is positioned on the rotor and has a surface of revolution. The grinding element is attachable to the rotor jacket on the surface of revolution and has a diameter increasing away from the material feed. A housing receives the rotor and rotor jacket therein, and has an opposing inner wall with a corresponding grinding element thereon. The grinding element on the rotor jacket includes a channel spaced from the material feed for the discharge of steam. The channel has one end in fluid communication with the grinding gap and a second end in fluid communication with a bore extending generally normally to the channel. The bore is in fluid communication with a cavity in the housing. The improvement comprises the grinding element on the rotor jacket being generally formed of a segment. The grinding element includes a surface facing the rotor axis and an anchoring projection of hammerhead-like cross section extending from the surface facing the rotor axis. The anchoring projection is engageable in a generally corresponding rotor groove of hammerhead-like cross section in the surface of revolution, such that the segments serves for the discharge of steam and is locked to the rotor jacket.