Abstract: Apparatus for controlling the refining of fibrous lignocellulosic pulp in a drum refiner in which the pulp stock, or grist, is conveyed into a cylindrical stationary drum and propelled therein in a linear direction in a pulsating fashion by a co-axial rotor comprising a plurality of wings which attack the grist in a wedging action as it is pushed ahead of the leading faces of the wings and which induce in the grist internal frictional shear forces while it is forced through a gap defined between the leading edges of the wings and a series of shear means arranged axially along the interior surface of the stationary drum. The process is controlled by coordinating the angle of attack on the grist by the wings and corresponding variations in the gap clearance with the energy demands or mechanical power input.

Abstract: Apparatus for producing pulp from lignocellulose-containing material in which the material is ground into grist in a grinding space defined between a rotating disc and a stationary disc mounted within a pressurized housing. Each disc comprises a series of annularly disposed arched segments having a plurality of radially extending bars and interconnecting transverse ribs defining a plurality of radially arranged pockets which in their radial cross sections have a curved contour. The pockets on one of the discs are offset radially from the pockets on the other disc, to allow the grist in the rotating pockets to be axially deflected by the centrifugal force created by the rotation and collected in an opposing offset pocket on the other disc. During the rotation of the disc, successive charges of grist deflected by the rotating pockets will force the grist previously collected in the stationary pockets to slide along the curved contour and be tilted or dumped into the corresponding offset rotating pocket.