Abstract: Method and apparatus for producing pressed board and the like in a tiered, multi-opening press, in which the sheet blanks are deposited individually on conveyor platens which are conveyed by conveyor means successively at predetermined intervals to a stacking device. In the stacking device, a predetermined number of platens with their superposed board blanks are successively raised above the conveyor means into retained contact with one another to form a stacked assembly of platens and board blanks. When the predetermined number of platens and board blanks have been stacked, the assembly is lowered onto the conveyor means and transported to tiered racks in an elevator device by which they are successively elevated into alignment with the tiered openings in the multi-opening press to be pressed into board units in a single pressing operation.

Abstract: A stream of disintegrated fibrous cellulosic pulp material and steam under pressure is subjected to an instantaneous pressure reduction as said stream and steam pass through a throttling nozzle, in a throttling zone, wherein a liquid solution of a bleaching agent is admixed with said stream and which stream, admixed with bleaching agent, is then passed into an expansion zone ahead of the throttling nozzle resulting in a uniform dispersion of the bleaching agent into the fibers in the stream of fibrous cellulosic pulp material.

Abstract: An improved apparatus and method for manufacturing ground wood pulp from ligno-cellulose containing wood block material by forcing the block material to be ground against the end surface of a rotatably mounted grinding disc which has projecting grinding means in the shape of elevations or ridges located on the disc end surface which define grooves directed towards the end surface circumference. The apparatus includes a pressure plate for pressing the block material along a longitudinal side against the disc end surface with the fibers directed outwardly from the center of the grinding disc and toward the periphery of circumference of the disc while the fibers are separated. In this manner the fibers are oriented in the same direction as the edges of the elevations or ridges which carry the fibers radially outward and the elevation edges engage the block fibers under a movement component which is transverse to the longitudinal direction of the fibers.

Abstract: The invention relates to a continuous method of making cellulosic pulp from wood chips within a range of yield from 65 to 90 per cent by digestion with a digestion liquor containing Na.sub.2 S and Na.sub.2 CO.sub.3. The digestion is effected at temperatures between 150.degree. and 190.degree.C and malodorous sulfur compounds are removed from the pulp, the liquor and the vapors prior to their withdrawal from the digesting process. In order to eliminate their capacity of emitting obnoxious odors, the sulfur compounds are oxidized by addition of molecular oxygen to the digester prior to discharge of pulp and spent liquor from the digester after which the spent liquor is removed from the digested pulp, concentrated and burned for renewed use in preparation of fresh digesting liquor.