Device in grinding apparatus for lignocellulose material

Abstract From the Canadian patent

Grinding apparatus in which lignocellulosic material such as wood chips is ground between a pair of grinding discs which rotate relatively to one another within a housing into which the material is advanced through a feed-in opening by means of a feed screw which rotates in a concentric sleeve extending between the central feed-in opening and an intake opening for the material. The feed screw comprises a series of inner screw flights mounted on a central shaft, which screw flights support and are enveloped by a series of outer ribbon-like screw flights. The inner screw flights are designed primarily to propel the material radially outwards towards the wall of the surrounding sleeve whereas …