FORFARANDE OCH ANORDNING FOR REDUKTION AV VID FRAMSTELLNING AV SLIPMASSA FRAN VEDSTOCKAR I STENSLIPVERK UPPKOMNA GROVRE VEDRESTER OCH SPETOR JEMTE REGLERING AV MASSANS FREENESS

Coarse wood residues, slivers and shives present in groundwood pulp as obtained in grinders are removed by passing a uniform flow of the pulp suspension containing coarse wood residues and shives from the grinder to a conical crushing and beating refiner having two treatment zones with a stationary part and a rotary part for reducing all wood material present in the suspension to free fibers, while measuring and controlling the freeness of the pulp within selected limits by controlling both the power input to the grinder and the power input to the conical crushing and beating refiner, and the degree of beating of the pulp, obtaining groundwood pulp having a low shives content and superior strength properties, at a low energy consumption.