Abstract: Methods of treating process water containing metal ions is disclosed including contacting the process water with a pulp comprising lignocellulose-containing material at a pH of above about 7 and a temperature of from about 50.degree. to 120.degree. C. whereby at least a portion of the metal ions are removed from the process water. Preferably the process water is produced from initially washing a pulp solution prior to a bleaching step employing hydrogen peroxide or ozone.

Abstract: Methods and apparatus for concentrating a liquid suspension of solid particles are disclosed including providing a screening web moving in an endless path, folding the screening web into a tubular configuration at a first location along that path, unfolding the screening web from that tubular configuration at a second location along that path, introducing the liquid suspension into the tubular configuration of the screening web proximate to the first location so that liquid can pass outwardly through the tubular configuration of the screening web and a concentrate of the solid particles can be formed therein, and removing the concentrate from the screening web proximate to the second location.

Abstract: A pressurized screen arrangement for screening lignocellulose containing fiber material, comprising a screen housing (10) with a screen cage (11) are arranged in first and, respectively, second attachment members (17, 18) in the screen housing. Both ends of the screen cage (11) are fitted into the attachment members (17,18) with radial clearance, and an axial support (21) is provided at least at one of the attachment members (17,18).

Abstract: A method of bleaching chemical pulp in a sequence comprising at least four bleaching steps with final bleaching in a first and a second chlorine dioxide step. Between the chlorine dioxide steps an alkaline extraction is carried out, and washing takes place between the first chlorine dioxide step and extraction. Immediately after said washing step, NaOH is charged in an amount of 4-10 kg/ton pulp. Thereafter an oxidizing agent is admixed in an amount of at maximum 2 kg/ton pulp. After 15-120 seconds an acid is added for terminating the oxidation treatment and for lowering the pH-value, but without effecting a complete neutralization of residual alkaline.

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.

Abstract: Apparatus for mixing a processing medium with the pulp suspension within a bin is disclosed, the apparatus including a housing attached to a wall of the bin, a rotary shaft extending through the housing with a propeller attached to the shaft by means of a hub, and a nozzle surrounding the propeller for directing the pulp suspension from an inlet in the nozzle to the propeller. The housing includes a dilution chamber for the processing medium and an outlet from the dilution chamber for directing the processing medium towards the hub, and includes a gap separating the outlet aperture from the hub so that the processing medium can be contacted with the pulp suspension before the pulp suspension reaches the propeller.

Abstract: Methods of manufacturing fiberboard from lignocellulose-containing fibrous material are disclosed including defibering the lignocellulose-containing material, drying the defibered lignocellulose-containing material by contact with a heated drying gas in a first drying step to produce a partially dried lignocellulose-containing material, mixing the partially dried lignocellulose-containing material with a glue, drying the admixture of partially dried lignocellulose-containing material and glue by contact with a heated drying gas in a second drying step, which is conducted at a lower temperature than the first drying step, independently controlling the temperature and moisture content in the second drying step to produce a dried lignocellulose-containing material having a predetermined temperature and moisture content, forming the dried lignocellulose-containing material into a fiber mat, and hot pressing the fiber mat into fiberboard.

Abstract: Apparatus is disclosed for heating cellulosic pulp in a pipe including fittings mounted on the outer surface of the pipe, and steam pipes connected to the fittings to supply steam thereto, the pipe including a number of apertures at locations corresponding to the fittings so that the steam can pass therethrough.

Abstract: Apparatus for refining fibrous material comprising first and second opposed refining disks, at least one of said first and second opposed refining disks being rotatable, a rotary shaft for rotatably mounting said at least one of said first and second opposed refining disks, a bearing housing for mounting said rotary shaft, a stand for stationary mounting of said bearing housing, said bearing housing including first and second bearings supporting said rotary shaft, said first bearing for at least carrying axial forces from said at least one of said first and second opposed refining disks and said second bearing for at least carrying radial forces therein, first and second bearing seats axially movable within said bearing housing, each of said first and second bearings being rigidly mounted in said first and second bearing seats, and prestressing structure mounted between said first and second bearing seats.

Abstract: Apparatus for controlling the flow of fibrous material is disclosed including a substantially horizontal feeder press, a rapidly rotatable spreader screw disposed in a vertical housing, with the outlet end of the feeder press connected to the vertical housing, at least two metering screws disposed below the outlet end of the vertical housing, and a spreader disk disposed at the outlet end of the vertical housing for disintegrating the fibrous material and distributing it to the metering housing containing the metering screws.

Abstract: Methods for mixing a treatment agent with a pulp suspension are disclosed including supplying the pulp suspension to a mixing chamber, moving the pulp suspension through a mixing zone with the mixing chamber, supplying the treatment agent to the moving pulp suspension across the entire width of the mixing chamber prior to the mixing zone, and in which the height of the mixing zone is sufficiently small such that the pulp suspension and the treatment agent are subjected to kneading within the mixing zone in order to repeatedly stretch and compress fiber flocks in the pulp suspension. Apparatus for mixing the treatment agent with the pulp suspension are also disclosed.

Abstract: Refiner segments for use in disk refiners for the disintegration of lignocellulose-containing material are disclosed, in which the refiner segment is formed with a pattern of bars and grooves and includes dams placed in the grooves. The dams are arranged so that their angle in relation to the radius of the refiner segment is less than about 30.degree., preferably less than about 15.degree..

Abstract: A refining segment for a disc refiner for defibering and processing lignocellulose-containing fiber material. The refining segment has the shape of a circle sector and a refining surface with bars and intermediate grooves, which extend across substantially the entire refining surface. The bars are oblique in relation to the radius of the refining segment, and the angle of the bars in relation to said radius is greatest closest to the center and thereafter decreases in radial outward direction. The angle closest to the center shall be in the interval 20.degree.-45.degree. and farthest out in the interval -10.degree. to +20.degree..

Abstract: A refiner for the manufacture of cellulose pulp where the raw material is processed in a gap between two opposed refining members rotary relative one another, and where at least one of the refining members is supported on a rotary refiner shaft (2) driven by a motor (4). An intermediate shaft (3) is connected non-rotary to a first and, respectively, second coupling (6 and, respectively, 7) between the rotor shaft (5) of the motor (4) and the refiner shaft (2) for transferring the drive moment. For damping the torsion oscillations in the mechanically connected shafts (2, 3, 5), an outer pipe (8) stiff against torsion is provided concentrically with the intermediate shaft (3), and one end of the pipe (8) is rigidly connected to the first coupling (6) at one end of the intermediate shaft, and the other end of the pipe (8) is connected by means of a friction damper (9) to the second coupling (7) at the other end of the intermediate shaft.

Abstract: A bearing system in a refiner for making pulp, where the raw material is refined in a refining gap between at least one pair of refining members (22, 24) rotating relative to one another, where at least one of said refining members (24) is supported by an axially movable and rotary shaft (26 ). The bearing system comprises a combined hydrostatic/hydrodynamic axial bearing arrangement and consists of a cylindric housing (32) with at least one rotary cylindric piston (30), which is mounted on the rotary shaft (26) for rotating together with the same. At least one outer and one inner concentric ring cylinder (200, 202 and, respectively, 210, 212) are arranged to abut one of the end surfaces of the rotary piston (30), so that a sealing gap is formed.

Abstract: A device for screening pulp suspensions includes a cylindric housing (1) with inject inlet (2), reject outlet (3) and accept outlet (4) and screening members in the form of a stator (5) and a rotor (8). The stator (5) as well as the rotor (8) include a plurality of annular elements (6 and 9, respectively), which are arranged in a mutual spaced relationship. The rotor (8) is located radially outside the stator (5), so that the rotor elements (9) are located directly in front of the spaces between the stator elements (6), and the axial length of the rotor elements is greater than the spaces between the stator elements. Thereby gaps (11) are formed between the stator elements and rotor elements.

Abstract: Devices for screening pulp suspensions are disclosed including a cylindrical screen extending longitudinally within a housing, an inlet for feeding the pulp suspension into the interior of the cylindrical screen, an accept outlet for removing the accept portion of the pulp suspension after it has passed through the cylindrical screen, a reject outlet for removing a reject portion of the pulp suspension at the opposite end of the cylindrical screen with respect to the inlet, and a rotor concentrically positioned for rotation within the cylindrical screen such that an annular screen chamber is created between the rotor and the screen, the rotor including wings extending from its exterior such that the wings have a length circumferentially with respect to the rotor which ranges from about 2:1 to about 6:1 with respect to the distance between the rotor and the screen, and the leading edges of the wings being separated a greater distance from the rotor than the trailing edges of the wings.

Abstract: A device for separating fibers and gas, comprising a cyclone (1) with inlet (2) for a mixture of fiber/gas and separate outlets (3 and 5, respectively) for fibers and gas, respectively. In front of the gas outlet (5) a screen (6, 10) is located, which is provided with apertures and attached on a rotatable shaft, so that the rotation of the screen gives rise to accelerations and forces preventing fibers from passing through the apertures in the screen (6, 10).

Abstract: The present invention relates to a device for protecting refining discs from excessive mechanical wear by preventing unwanted debris from coming between the discs.