Abstract: The method is for producing pulp. More particularly, a displacement batch cooking process comprises recovery of a first treatment liquid by draining of the digester, preferably not using a displacement liquid. The method may preferably be used in a prehydrolysis step, wherein the recovery of the by-products is improved. In the recovery step, after the target P-factor in the prehydrolysis stage is reached, the hydrolysate is withdrawn by draining in at least one phase obtaining a strong first liquid and thereafter any residual hydrolysate may be displaced.

Abstract: The present invention relates to an improved process for producing dissolving pulp from a hydrolysis-kraft cooking process, and wherein production increases may result in less viscosity reduction and thus not meeting the target viscosities in the dissolving pulp produced. In order to compensate for losses in viscosity reduction in the cook at production increases is the oxygen delignification stage boosted with modest charges of peroxide that introduce an additional viscosity reduction.

Abstract: In an outlet flow control arrangement (1) arrangeable to control a flow of material through an outlet (2) with a predetermined diameter arranged at an end of a pressurized processing container (3), the outlet flow control arrangement (1) comprises an adaptor unit (4) configured so that a cross-section of a flow into the adaptor unit (4) is reduced as compared to a cross-section of the outlet (2), to enable the adaptor unit (4) to control and center a flow of processed material out of the processing container (3) and through the outlet (2) into a discharge pipe (5).

Abstract: The method is for producing pulp in batch digesters. More particularly, the method is for ending a treatment phase of the digester content. In order to obtain a more uniform pulp quality from the process is the treatment phase ended by displacing a liquor volume (WLP) through the digester vessel with an imposed increasing temperature in the displacement liquor added to digester.

Abstract: A feeding arrangement for feeding comminuted material to a treatment stage using a plug screw feeder. The invention relates to a design of the inlet to the plug screw feeder wherein, at least 2 chutes (20a,20b) are arranged to feed material to the feed screw (10), and that the cross section of each chute is arranged such that more than 50% of the outlet cross section of a first chute (20a) is located on one side of the feed screw axis (CC) and more than 50% of the outlet cross section of a second chute (20b) is located on the other side of the feed screw axis. In an upgrade version for existing plug screw feeders with large rectangular inlets is an insert body (11a) used filling the rectangular inlet, besides the chutes (20a, 20b) passing through the insert body (11a).

Abstract: Apparatus for washing and/or dewatering cellulose pulp is disclosed including a movable permeable surface in a pulp transportation chamber having a chamber gap above the movable permeable surface, a pulp distributor for distributing pulp onto the movable permeable surface, a throttle having a throttle gap width and an adjustable throttle adjuster to remotely adjust the throttle gap width so that a volume of pulp flow into the pulp distributor is equal to or greater than the volume of pulp flow out of the distributor during operation.

Abstract: A refiner segment (1) for a refiner intended for defibrating lignocellulose-containing material has a refining surface comprising a group of first bars (10) and second bars (20), each first and second bar having a first end (10-1, 20-1) directed in the direction of an inlet zone (2) of the refiner segment and a second end (10-2, 20-2) directed in the direction of a refining zone (3) of the refiner segment, where the second ends (10-2) of the first bars (10) are interlaced with the first ends (20-1) of the second bars (20) to form first grooves (30-1) between the first bars (10), and second grooves (30-2) between the second bars (20).

Abstract: The method is for the preparation of kraft pulp with increased pulping yield from lignin-containing cellulosic material using polysulfide cooking liquor. In order to increase carbohydrate stabilization and hence the yield from a kraft cooking process a first impregnation stage using polysulfide cooking liquor is implemented at high alkali and polysulfide concentration and at a low temperature. Knots are added to a high-pressure conduit extending between an impregnation vessel and a digester.

Abstract: The improved method and arrangement are for cooling torrefied lignocellulosic material. By adding water in controlled amounts to the torrefied material in a grinder at exit from a roaster the entire volume of torrefied material could be cooled down to a temperature well below the critical temperature without increasing the water content of the final product.

Abstract: A feed screw for feeding lignocellulosic material to a rotary disc refiner is disclosed. The feed screw includes at least one peripheral thread for feeding the lignocellulosic material axially towards the disc refiner and the feed screw feeds the lignocellulosic material from its upstream end towards its downstream end through the center of the opposed grinding surfaces of the disc refiner, the downstream end of the peripheral thread including an angled end part disposed at an angle with respect to the peripheral thread such that the lignocellulosic material is redirected in a radial direction as it leaves the end of the peripheral thread.

Abstract: Refiner comprising relatively rotatable inner 2 and outer 3 conical refining blades. The refining blades 2, 3 being coaxially arranged around a symmetry axis 6 and being provided with first bars 200 and second bars 300, respectively, for grinding of fibrous material. The inner conical refining blade 2 or any of the first bars 200 of the inner conical refining blade 2 extends further along the symmetry axis 6, in the direction of the tapering of the inner 2 and outer 3 conical refining blades, than the outer conical refining blade 3 or any of the second bars 300 of the outer conical refining blade 3.

Abstract: A dewatering roll (10) comprises a roll body (20), a mantle support structure (30) and a mantle (40). The mantle support structure (30) is attached around the roll body (20). The mantle (40) is attached against an outer surface (36) of the mantle support structure (30). The mantle (40) has a plurality of through holes (42) constituting mantle flow paths (44). The mantle support structure (30) presents support flow paths (38) from the outer surface (36) of the mantle support structure (30). The support flow paths (38) are in fluid contact with the mantle flow paths (44). The outer surface (36) of the mantle support structure (30) has a static geometric shape defining an envelope having a smaller radius in vicinity of each axial end (15) than in vicinity of a centre (16). Thereby, the inner surface (48) of the mantle (44) assumes the shape of the envelope.

Abstract: A mixing unit (10) for use in a mixing apparatus (100) for mixing chemicals in liquid or gaseous state into a fiber suspension, which apparatus comprises a housing (101) defining a mixing chamber (102), a first inlet (103) for feeding a pulp suspension to the mixing chamber, a second inlet (104) for feeding treatment media into the mixing chamber, a drive shaft (105) connected to a drive device (106) for rotation of the drive shaft in operation, and an outlet (107) for discharging the mixture of pulp suspension and treatment media, said unit (10) for mixing being adapted to be installed in the mixing apparatus and comprising a rotor (11) comprising a rotor shaft (11a) being arranged to be connected to the drive shaft (105) for, in operation, simultaneous rotation with the drive shaft, at least two rotor bodies (11b, 11c) arranged on the rotor shaft (11a), each having a radial extension, the bodies being arranged to be axially separated from each other along the rotor shaft (11a) and adapted to cooperate so as

Abstract: A screw conveyor for transporting lignocellulose-containing material, including a housing containing a screw for transporting the lignocellulose-containing material from the inlet to the outlet of the housing, the screw including a screw core disposed along the screw axis and a screw thread surrounding the screw core, the screw thread including a screw depth defined by the distance between the periphery of the screw and the screw core, the inlet including at least one transverse plate dividing the inlet into at least two axial compartments for evenly distributing the lignocellulose-containing material at the inlet. A method for transporting lignocellulose-containing material by the screw conveyor, in which the axial length of the screw inlet being equal to or greater than the screw depth times the quotient between the axial speed of the screw and the incoming speed of the lignocellulose-containing material at the inlet.

Abstract: The method and equipment relates to the measurement of deflections of filter sectors in a disc filter. The filter discs in the disc filter are constituted by a number of filter sectors, and the distance between a position fixed relative to the filter, most commonly the scraper itself, and the filter surface is conventionally measured by manual measurement methods. The equipment is instead used that has a measuring head with a quick-release coupling for its mounting fixed in the filter, and a position sensor in the measuring head that measures the distance between the measurement arrangement and the surface of the filter disc in order to form momentary measurement results. The momentary measurement results are transferred by a data transfer link from the measurement arrangement to a data collection unit PC that has a memory.

Abstract: The invention relates to an improved design of the bottom of a continuous digester reducing the torque load on conventional bottom scrapers with scraper arms arranged at an angle ? in relation to the horizontal plane in the range between 5°-30°. A simple digester shell extension VE is installed below the lowermost wash screen WS, ending at a small distance D above the end of the outer end of the scraper arm. The shell extension prevents the descending pulp column from expanding below the wash screen and enables easier shaving action from the scraper, using a dilution and expansion volume established at the outer ends of the scraper arms.

Abstract: The method is for separation of lignin from original black liquor (BLIN) having the following phases in sequence; a first precipitation phase (PR1) for precipitation of lignin by a first acidification of the original black liquor by adding a first acid or mixture of acids (G1a); followed by a second precipitation phase (PR2) for precipitation of lignin by a further acidification of the original black liquor by adding a second acid or mixture of acids (G1b). The first phase is implemented to lower the pH while avoiding any larger amount of precipitation, i.e. less than 2-5%, while the second phase is implemented in order to obtain the larger part of the precipitation. In total is 40-70% of the total lignin content of the original black liquor precipitated while the residual black liquor after precipitation is still strongly alkaline.

Abstract: A center plate for a rotor in a pulp refiner is described in which the center plate is provided with a plurality of first wings for directing pulp flowing onto the center portion of the center plate towards the periphery of the center plate, each of the first wings comprising an arc-shaped protrusion extending between a corresponding first point and a corresponding second point on the surface of the center plate, the first point being displaced from the center portion of the center plate and the second point being disposed further from said center portion of the center plate then the first point, the first wings having an arc shape that yields a larger pulp feeding angle then that of a circular arc intersecting the center portion of the center plate and ending in the same corresponding second point, and the second point of each of the first wings lies on the periphery of the center plate.

Abstract: A screw conveyor for transporting lignocellulose-containing material is disclosed, including a housing containing a screw for transporting the lignocellulose-containing material from the inlet to the outlet of the housing, the screw including a screw core disposed along the screw axis and a screw thread surrounding the screw core, the screw thread including a screw depth defined by the distance between the periphery of the screw and the screw core, the inlet including at least one transverse plate dividing the inlet into at least two axial compartments for evenly distributing the lignocellulose-containing material at the inlet. A method for transporting lignocellulose-containing material by the screw conveyor is also disclosed, in which the axial length of the screw inlet being equal to or greater than the screw depth times the quotient between the axial speed of the screw and the incoming speed of the lignocellulose-containing material at the inlet.

Abstract: Apparatus for washing and/or dewatering cellulose pulp is disclosed including a movable permeable surface in a pulp transportation chamber having a chamber gap above the movable permeable surface, a pulp distributor for distributing pulp onto the movable permeable surface, a throttle having a throttle gap width and an adjustable throttle adjuster to remotely adjust the throttle gap width so that a volume of pulp flow into the pulp distributor is equal to or greater than the volume of pulp flow out of the distributor during operation.