Abstract: Apparatus for refining lignocellulose-containing material is disclosed including a pair of opposed refining disks defining a refining gap for the lignocellulose-containing material, at least one of the refining disks including an outer refining zone section which includes three refining zones including radially extending bars and corresponding radially extending grooves in which the first and third refining zones have a different bar density than the intermediate or second refining zone. Apparatus is also disclosed which includes a pair of opposed refining surfaces in which each disk refiner includes a pair of refining zones with one of each pair on each disk having a different bar density, and with the two zones being radially offset so that the like refining zones in each disk do not overlap with each other.

Abstract: A refining element is disclosed for use in a disk refiner having a refining element holder surface including a plurality of attachment holes, the refining element including a plurality of working members on its front surface and a rear surface adapted to be attached to the refining element holder, the refining element further includes a plurality of attachment through holes extending through the refining element for attachment to the refining element holder at corresponding attachment holes therein, whereby attachment screws can be provided for affixing the refining element to the refining element holder through the plurality of attachment through holes, and at least one removal hole including threads and being substantially centrally located on the refining element, whereby the refining element can be removed from the refining element holder by extending a removal screw through the removal hole to apply pressure for removal of the refining element against the refining element holder.