Abstract: Sorbed sodium ions in the wood pulp are recovered in the washing operation following cooking with the minimum use of pH control acid, thereby reducing cost and any possible undesirable side effects. A washing press is used in the pulp process. Means are provided for adding an acidifying chemical to the washing press for controlling pH of the pulp suspension. The filtrate from the washing press is divided, with the larger portion of the filtrate being fed to the pulp suspension line to the washing press for pulp suspension pH control. A smaller portion of the filtrate is fed countercurrently through the brown stock washing system. The chemicals are then recovered from the brown stock washing system filtrate.

Abstract: A batch type digester for wood chips in which a stream of wood chips is delivered into the center of the top of the digester tank, while liquor is being delivered through a pair of pipes at the top of the tank. Simultaneous with the delivery of the wood chips and liquor, a steam vortex is formed in the upper part of the tank by a plurality of steam jets which are directed downwardly and tangentially and form spiral flow paths below the streams of chips and liquor. The wood chips and liquor are dispersed together and the liquor thoroughly wets the chips. The chips produce a substantially even layer as they fall to the bottom of the tank. The steam vortex maintains a negative relative pressure zone which promotes the dispersion of the stream of chips and the liquor.

Abstract: The continuous treatment of a cellulosic material in the form of chips to produce at least partial delignification of the material without true mechanical grinding is effected in apparatus comprising two parallel meshing screws which are rotated in the same direction in a sheath and have identical threads providing a plurality of zones of different pitch. The material is passed in succession through a first zone for feeding the material downstream, a first braking zone for causing a first compression of the material, a second zone for feeding the material downstream and in which the material is brought into contact with a reagent, e.g. steam or a chemical reagent, and a second braking zone for causing a second compression of the material.

Abstract: Apparatus for the displacement washing of cellulose fibers suspended in a liquid, as produced by cooking wood pulp in a digester vessel 1. As the fiber suspension settles to the bottom of the vessel it passes through a plurality of axially spaced washing zones 6, whereat water is forced through the suspension in a radial direction from central inlet conduits 16, 16a, 16b to peripheral outlet chambers 9, or vice versa. Such flow displaces the suspension or cooking liquid, and the washed fibers are withdrawn through a bottom outlet 5. The washing liquid is sequentially recirculated through the zones 6 for economy, and the buildup of fibers on the recirculating conduits 19a, 21a, 24a in the vessel is prevented by perforated water discharge pipes 26 disposed just above the conduits.

Abstract: Apparatus for the production of a lignocellulose material from chips, sawdust, chopped plants, bark, small fibres comprising a vertical column with a series of successively-mounted horizontal perforated plates partly abutting upon the inner surface of the column; at the free ends of said plates retaining baffles are secured for partial entrapment of coarse particles of the product; a clearance is provided between the baffle and inner surface of the column and the plates are disposed relative to each other so that baffles of each successive plate are located diametrically opposite to the baffles of each preceding plate thus forming a zigzag labyrinth along the total height of the column for increasing the time of contact of coarse particles of the raw materials with the oxygen-containing gas and alkaline reagent.A pulsator means is operably connected to the column for setting liquid reagents in the column into reciprocating vertical motion.

Abstract: An apparatus and method for the treatment of cellulosic fiber material with maximum efficiency while minimizing capital costs. Fiber material entrained in digesting liquid is impregnated with the liquid in an impregnation vessel, sluiced to a separate digesting vessel, and from the digesting vessel sluiced to one or more separate washing vessels without a significant reduction in pressure. Countercurrent washing is effected in the washing vessel(s). Digesting liquid withdrawn from the digesting vessel is heated in a transfer line back to the impregnation vessel.

Abstract: A batch type digester for wood chips in which a stream of wood chips is delivered into the center of the top of the digester tank, while liquor is being delivered through a pair of pipes at the top of the tank. Simultaneous with the delivery of the wood chips and liquor, a steam vortex is formed in the upper part of the tank by a plurality of steam jets which are directed downwardly and tangentially and form spiral flow paths below the streams of chips and liquor. The wood chips and liquor are dispersed together and the liquor thoroughly wets the chips. The chips produce a substantially even layer as they fall to the bottom of the tank. The steam vortex maintains a negative relative pressure zone which promotes the dispersion of the stream of chips and the liquor.

Abstract: In the continuous production of paper pulp from ligno-cellulose raw material, the raw material is subjected to grinding and/or delignification by passing it in the form of small pieces between interpenetrating helicoidal surfaces driven synchronously in rotation inside a casing. The pitch of the helicoidal surfaces is arranged to provide at least one supply zone in which the material is driven downstream by rotation of the surfaces and at least one braking zone in which the material is braked.

Abstract: A device for the counterflow treatment of fibrous deformable particles with liquid in stages in a tower. In the tower the particles and liquid flow downward by small movements and the liquid flows upwardly. Each of these successive two movements constitute one stage. The ascent of liquid alone, or filtration in each stage, is produced by introductions of water with adequate pressure through the bottom of the tower. The descent of the mass of particles and liquid or mass movement in each stage, is produced by rapid removal of mass from the lower part of the tower. During filtration periods, the particles suffer only small relative displacements among them, because the upper layer of the particles is retained by a screen, that only permits the flow of liquors; in addition, successive grids extending from the proximity of the screen to the proximity of the bottom of the tower, offer resistance to movement of the particles.

Abstract: Apparatus for refining digested pulp involving the use of a refiner, preferably two or more refiners in series positioned in the digester blow line to receive washed, digested pulp discharged from a continuous digester.

Abstract: A paper fiber treatment system utilizes a screw revolving in a perforated cylinder as a tailings screen in place of conventional vibratory or other screens to separate undefibered fibrous materials or other undesirable solids from the free fibers. The tailings screen may be used, for example, in an otherwise conventional fiber treatment system to screen paper stock, downstream from a pulper for pulping waste paper or refuse containing a high percentage of paper fibers, or downstream of a digester for separating knots or other undefibered wood particles from the cooked fibers ejected from the digester.