Abstract: Hydraulic systems are disclosed for operating a press comprising a press ram, a press cylinder including a primary side for activating the press ram and press ram return cylinders for returning the press ram, and at least one flow amplifier comprising a piston including a primary side and a secondary side, the primary side of the piston including a large piston area and a secondary side of the piston having a small piston area, the primary side of the piston being connected to the primary side of the press cylinder and the secondary side of the piston being connected to the press ram return cylinder, at least a portion of the hydraulic system comprising the connection between the primary side of the piston and the primary side of the press cylinder is pressurized.

Abstract: A pressure screen for separating a liquid mixture is disclosed, comprising a screen housing forming a cylindrical screen chamber, and an inlet housing directly connected to the screen housing and forming a cylindrical inlet chamber, the diameter of which is less than the diameter of the screen chamber. An inlet member is positioned on the inlet chamber for supplying a suspension to be separated substantially tangentially into the inlet chamber and an outlet member is positioned on the inlet chamber for discharging coarse contaminants from the inlet chamber, whereby the scrap particles are prevented from entering the screen chamber.

Abstract: Processes are disclosed for bleaching pulp with ozone in an environmentally friendly bleaching plant. The processes include removing a first filtrate from the pulp, bleaching the treated pulp with ozone, washing the bleached pulp with a washing liquid to provide a washed bleached pulp and a second filtrate including oxalic acid, recycling the second filtrate to the pulp prior to the bleaching step, and transferring the first filtrate to the bleached pulp.

Abstract: Apparatus for mixing steam or bleaching agents with a pulp suspension is disclosed, including a chamber for receiving the flow of pulp suspension from an input line, the chamber including a jacket surrounding the flow of pulp suspension through the chamber, the inlet to the chamber defined by an inlet flange having a diameter which is smaller than the diameter of the input line, and the jacket including a supply orifice for supplying the steam or bleaching fluid to the flow of pulp suspension in the chamber.

Abstract: Methods are disclosed for securing a wrapper about a bale which is intended to be subsequently treated comprising inserting a fastener pin through the wrapper into the bale, the fastener pin being adapted to remain in the bale during subsequent treatment thereof. Fasteners are also disclosed for securing wrappers about bales.

Abstract: A screen device for separating fiber suspensions comprises a screen (40) defining a central chamber (36), and a rotor (15) in the central chamber having a first (21) and a second (27) rotor portion, respectively, provided with first (43) and second (41) pulsation elements, respectively, for pulsating the suspension close to the screen along a first (11) an a second (9) axial screen portion, respectively, of the screen. The first rotor portion (21) and the first axial screen portion (11) define a first screen chamber (39) and the second rotor portion (27) and the second axial screen portion (9) define a second screen chamber (37). Distribution means (22, 28) are provided for dividing the incoming fiber suspension into two part streams having the same axial directions in relation to the rotor and for distributing the two part streams to the first and second screen chambers (39, 37), respectively.

Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.

Abstract: Feeding elements are disclosed for use in connection with refiners for lignocellulosic fibrous material including a stationary refiner, a rotary refiner mounted for rotation in juxtaposition with the stationary refiner thereby forming a refining gap therebetween, a feeder for feeding the lignocellulosic fibrous material centrally to a central feed zone within the refining gap and a refining zone extending radially outward from the central feed zone, the feeding element including a disk for mounting on the rotatable refiner at a central location in the central feed zone, the disk including at least one radially projecting strip extending from the central portion of the disk towards the outer circumference of the disk and including a body and a projecting portion extending laterally from the body at a location displaced from the upper surface of the disk for a major portion of the radially projecting strip.

Abstract: Screening apparatus is disclosed for separating fiber suspensions comprising a housing having an inlet for the fiber suspension, a stationary tubular screen dividing the interior of the housing into a central chamber for receiving the fiber suspension from the inlet and an outer accept chamber for receiving an accept portion of the fiber suspension which has passed through the stationary tubular screen, a rotor journalled on the housing for rotation within the central chamber coaxially with the stationary tubular screen, the rotor including a rotationally symmetrical element, a reject chamber for receiving a reject portion of the fiber suspension at one end of the stationary tubular screen, and an annular passage for dilution liquid including a stationary annular wall portion juxtaposed with the rotationally symmetrical element of the rotor.

Abstract: Apparatus is disclosed for spreading and distributing particles such as glue-coated wood fibers onto a moving web including rotatable axles disposed transverse to the direction of movement of the moving web with each axle including a number of distributors rotatable with the axles and disposed generally obliquely with respect to the axes of the axles, each of the axles disposed at successively increasing heights from the moving web in its direction of movement whereby each of the distributors extends into the wood fiber particles comprising the moving web and distributes the particles across the moving web.

Abstract: A method and apparatus for wrapping bales of pulp are disclosed, the method comprising transporting the bales between upper and lower conveyors, applying a first wrapping sheet to the lower surface of the bale, applying a second wrapping sheet to the upper surface of the bale, measuring the height of the bale prior to transporting it between the upper and lower conveyors, and adjusting the distance between the upper and lower conveyors based upon the measured height of the bale such that both of the wrapping sheets are uniformly disposed on the upper and lower surfaces of the bale. The apparatus includes an upper conveyor, a lower conveyor juxtaposed with the upper conveyor, such that the bales may be transported between the upper and lower conveyors, a transmitter for measuring the height of the bales upstream of the upper and lower conveyors, and a positioner for adjusting the distance between the upper and lower conveyors based on the measured height of the bales.

Abstract: Methods of controlling oxygen delignification processes are disclosed including providing chemicals for a first oxygen delignification step, conducting the first oxygen delignification step with the chemicals, conducting a second oxygen delignification step at a predetermined temperature to produce a delignified pulp, measuring the final kappa number of the delignified pulp subsequent to the second oxygen delignification step, adjusting the chemicals provided for the first oxygen delignification step based upon the difference between the actual kappa number reduction and the desired kappa number reduction for the pulp, and adjusting the predetermined temperature based on the chemicals provided to the first oxygen delignification step in order to provide the delignified pulp at a final pH of from about 10.5 to about 11.5.

Abstract: A feeding element is disclosed for use in connection with a refiner for lignocellulosic fibrous material including a stationary refiner, a rotary refiner mounted for rotation in juxtaposition with the stationary refiner thereby forming a refining gap therebetween, a feeder for feeding the lignocellulosic fibrous material centrally to a feed zone within the refining gap and a refining zone extending radially outward from the feed zone, the feeding element including a feeder with an upper surface for mounting on the rotary refiner at a location displaced outwardly from and directly adjacent to the central location of the feed zone, the feeder including at least one radial feed bar projecting from the upper surface of the feeder, the at least one radial feed bar including a body and a projecting portion extending laterally from the body at a location displaced from the upper surface of the feeder.

Abstract: Methods for oxygen delignification of a pulp are disclosed, including initially delignifying the pulp at a delignification temperature of less than 90° C., adding oxygen to the pulp so that the oxygen is present during the initial delignification step, and further delignifying the pulp at a delignification temperature of greater than 90° C., the difference between the two delignification temperatures being less than about 20° C., and the pressure being greater in the initial delignification step. The method also includes adding alkali solely to the initial delignification step in order to obtain high alkalinity therein.

Abstract: Methods for oxygen delignification of chemical pulps are disclosed including contacting the chemical pulp with oxygen first in an upstream reactor vessel and then in a downstream reactor vessel. The upstream reactor vessel is maintained at pressures of greater than about 3 bar, and the downstream reactor vessel is maintained at temperatures of between about 90 and 120° C. and corresponding predetermined pressures. Heating of the partially delignified chemical pulp between the upstream and downstream reactors is accomplished by contacting the partially delignified chemical pulp with low pressure steam.

Abstract: Screen panels are disclosed for the screening of fibrous material. The screen panels are one-piece screen panels which can then be incorporated into a cylindrical screen jacket without the use of welding. The screen panels include a plurality of apertures for the fibrous material and are made from a wear-resistant material. Methods for producing these screen panels are also disclosed.

Abstract: Apparatus for treating an aqueous medium with a treatment fluid including a housing forming a treatment chamber, a rotatable rotor arranged in the treatment chamber, and including a number of rotor rings carried by the rotatable rotor and coaxially arranged at the periphery of the rotatable rotor, a number of stationary stator rings coaxially inserted between the rotor rings thus forming a number of annular axial treatment slots which have a radial size between the rotor rings and the stationary stator rings, the radial size of these slots increasing with increasing distance from the axis of the rotatable rotor, an inlet for delivering the working medium and the treatment fluid to one side of the annular axial treatment slots and an outlet for the treated working media disposed at the other side of the annular axial treatment slots, whereby the working medium is sheared in the treatment slots during operation so that substantially homogeneous shearing velocities are achieved in each of these slots.

Abstract: Methods and apparatus are disclosed for refining lignocellulosic material between a pair of relatively rotary refining elements forming an annular outer refining zone and a central feed zone. The method includes feeding the lignocellulosic material to the central feed zone, accelerating the lignocellulosic material through the central feed zone towards the annular outer refining zone without lignocellulosic material build up in the central feed zone and substantially without working the lignocellulosic material in the central feed zone, the density of the lignocellulosic material in the central feed zone being a maximum of about 10 kg/m3, and mechanically working the lignocellulosic material in the annular outer refining zone, and in which the relatively rotary refining elements have a relative speed of greater than about 50 m/sec.

Abstract: Screening apparatus is disclosed for separating fiber suspensions including a housing having an inlet for the fiber suspension, a stationary tubular screen having an inlet end adjacent to the housing inlet and an outlet end, and dividing the interior of the housing into a central chamber for receiving the fiber suspension from the inlet, and an outer accept chamber for receiving an accept fraction of the fiber suspension, a rotor journalled on the housing for rotation within the central chamber coaxially with the stationary tubular screen, a reject passage for receiving a reject portion of the fiber suspension at the outlet end of the stationary tubular screen, and an annular reject passage which has a radial width and a cross-sectional area at the outlet end of the stationary tubular screen for discharging the reject portion of the fiber suspension from the central chamber to the reject passage, the annular reject passage including an annular flange attached to the inner wall of the passage, resilient tubing

Abstract: Methods and apparatus are disclosed for degassing gas-containing fluid media in a container with the apparatus including a centrifugal pump for pumping the gas-containing fluid medium from the container, an ejector including a suction side, an ejector inlet for a drive fluid, and an ejector outlet for the drive fluid, whereby at least a portion of the pump fluid medium is fed to the suction side of the ejector for removing the gas therefrom, a diversion conduit for diverting a separate portion of the pump fluid medium from the centrifugal pump to the ejector inlet, and a return conduit for returning the separate portion of the fluid medium from the ejector outlet to the container.