Abstract: Sealing device for preventing leakage of pressurized medium from the housing of a defibrator, refiner and the like, in which lignocellulosic pulp material is ground between two grinding discs, one of which is mounted on a drive shaft to rotate relative to the other within the pressurized housing. The sealing device comprises a pump having a stationary housing sealed to the defibrator housing and spaced from the drive shaft to define a gap extending into the interior of the defibrator housing. The pump impellers are mounted to rotate with the drive shaft to pump a sealing fluid to a pressure higher than that prevailing within the defibrator housing and propel the thus pressurized fluid through the gap into the defibrator housing to thereby prevent leakage of the pressurized medium through the drive shaft opening in the defibrator housing.

Abstract: A grinding apparatus in which lignocellulosic material is ground between a pair of discs which rotate relatively to one another in a pressurized housing. The stock is advanced by means of a screw feeder, through a central opening in the disc housing and introduced into the grinding space between the discs under maintenance of the pressure within the housing. Excessive high-pressure steam or other gas generated during the grinding process is separated from the ground stock, which is returned to the grinding space by centrifugal force, while the steam or other gas freed of stock particles is discharged without interfering with the stock inflow.

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: The invention relates to a screw press for dewatering suspended fibrous pulp. The press comprises a tubular casing with perforated wall and a screw member rotatable within the casing. The desired degree of dewatering is controlled by a throttling member adjustable so as to generate a predetermined counter-pressure against the pulp advanced by the screw member. It rather often occurs that the pressure produced in the press becomes so high that the rotation of the screw member is stopped which means total stop of the operation of the press. The invention provides means adapted automatically to avoid such undesired stop in operation by relieving the press from internal pressure exceeding a predetermined, adjustable value.

Abstract: Device for counteracting imbalance in a rotary body and automatically restoring it to a balanced condition. The device comprises a fluid-filled bore in which a throttling member moves freely, which transmits the pressure differentials developed about the axis of rotation during rotation of the body to a balancing mass movable in chambers disposed about the bore to displace the balancing mass a distance proportional to the pressure differentials and is effective upon the balancing mass to restore the body to balanced condition.

Abstract: The invention relates to a device for sealing a casing housing a machine element the rotatable shaft of which passes through the casing within which a pressure differing from that of the outside the casing is maintained. To provide a perfect sealing at the shaft passage, a liquid seal is formed by novel specific means. In a preferred embodiment where the device is combined with an apparatus the shaft of which passing through at least one wall of the casing is axially displaceable, the specific sealing means are displaceable together with the shaft while completely maintaining the sealing effect.

Abstract: Grinding discs in apparatus for manufacture of pulp composed of a support disc and segments mounted on said support disc so as to form a ring. The segments are formed with ribs and grooves for breaking down the material to be ground. The outer and inner peripheral edges form together common edge lines following a wave-shaped contour line. The invention also includes a method of manufacturing segments which when annularly mounted on a support disc present wave-shaped common outer and inner peripheral edge lines.