Abstract: The invention relates to a process and apparatus for pretreating pulp raw material, to be subsequently prepared in a chemical pulping process, and for preparing cellulose pulp from a fibrous starting material. According to the process the starting material is delignified to yield a chemical cellulose pulp, and the obtained pulp is bleached when desirable. According to the invention the starting material is crushed in cooking liquor prior to delignification in order to open its fiber structure. The apparatus of the invention comprises a frame (21), to which to adjacent first rolls (12; 22, 23) have been fitted, which form a first pair of rolls with the rolls arranged to distance from each other in such a manner that a gap clearance is formed between their outer mantles. The rolls are caused to rotate by a means of power transmission, which causes the raw material to be crushed inside the gap between the rolls where a liquid pocket is formed, from which liquid is absorbed into the fiber material being treated.

Abstract: The invention concerns a knife disc arrangement of a disc chipper, said arrangement comprising a rotating knife disc (1), knives (3), wear plates (4) and supporting strips (11) supporting the wear plates. The invention also concerns a hinge strip acting as a supporting strip (11) for the wear plate. The knives are supported against the direction of rotation of the disc by fitting the base edge (9) of the knife against a supporting surface (10). The supporting surface (10) supporting the base edge of the knife (3) is located in the supporting strip (11).

Abstract: A method of increasing the durability of the cutting point (8) of a blade, and a blade. A compression stress (P.sub.10) is formed in at least one surface (10 or 6) joining the point (8) of the blade (1) by cold working the blade.

Abstract: A screw conveyor is provided with a drive in which cogged wheels are supported such that they are radially movable in relation to each other, parallel to a straight line perpendicular to a pressure line of tooth contact of the cogged wheels and parallel to surfaces of contact. The screw conveyor includes a frame adapted to turn around a vertical turning axis and a conveyor screw adapted to turn with the frame. A second one of the cogged wheels is supported such that it is movable vertically.

Abstract: A method for mounting a wear plate and a knife base on a disc chipper's disc, and a disc chipper. The wear plate (6) rests against the knife base (4) via two counter surfaces (12), one of which forms in the wear plate (6) a groove in parallel to the knife (3) and the other forms in the knife base (4) a ridge which can be fitted into this groove. The tightening force of the fastening bolts (17, 18) of the wear plate (6) presses the knife base (4) against the disc (1) by means of the wear plate via these counter surfaces (12).

Abstract: A method for improving the endurance of a blade base (6) of the disc (1) of a disc chipper, a blade base and a disc chipper. A wearing plate (10) is attached to the surface (18) of the blade base facing towards the chip opening (7), the wearing surface (10) of which is shot peened.

Abstract: A method for adjusting the blade clearance in a disc chipper by moving in the axial direction a bearing bushing of a disc shaft together with the bearing. The axial movement of the shaft is effected by loosening adjusting screws or adjusting nuts of one of the end caps of the axial guide bearing housing and by tightening after this the adjusting screws or adjusting nuts of the other end cap. The cap then pushes the axial guide bushing and the attached shaft in the axial direction by way of a guide projection on the surface of the cap facing towards the bearing. An axial guide bearing system includes a shaft supporting a blade disc of a disc chipper, with the shaft and blade disc being movable relative to a counter blade in an axial direction. The system also includes a bearing housing frame and a bearing fixed to the shaft and movable with respect to the bearing housing frame.

Abstract: A drive system of a rotating drum (1), where the drum is supported with a flexible support system. The drive system consists of a gear rim (2) and a pinion gear (4) in contact with the gear rim. The driving pinion gear is supported on a moving platform (10). The drum (1) is provided with a guiding rim (5) and a guiding wheel (6) rolling against it and supported on the same platform as the driving pinion gear. The sum of the outer diameters (D.sub.2 and D.sub.1) of the guiding rim (5) and the guiding wheel (6) is equal to the sum of the pitch diameters of the gear rim (2) and the driving pinion gear (4). The guiding wheel (6) can be pressed against the guiding rim (5) to maintain the right clearing between the teeth of the pinion gear (4) and the gear rim (2) when the center of the drum (1) is moving.

Abstract: The invention relates to a knife system for a machine used in wood chipping, a knife (10), a guide component (14) and a filler part (24) and method of exchanging knives. The system comprises at least one turnable or at least two exchangeable guide components (14), where at least two guiding surfaces are mutually at different distances from the guide component surface supported on the disc.

Abstract: A chipping control device (9) to be mounted on a disc chipper and a disc chipper for keeping the piece size of the chips (8) removed from the wood (1) with a chipper blade (6) uniform. The chipping control device (9) is mounted on the outer surface of the blade disc (4) on the opposite side of the blade (6) such that the control device (9), when using the chipper, contacts the chips (7, 8) leaving the chipping opening (13).

Abstract: A method and press for pressing material by way of feeding the material into a gap formed between two pressing surfaces, in which gap the cross section of the material flow is tapered in the forward transfer direction of the material. The material is pressed between pressing surfaces formed by parallel, beam-shaped transfer elements which are reciprocatingly moved in the direction of material flow in two alternating groups so that the mutually opposed transfer elements of both pressing surfaces are moved in a mutually synchronized manner in the same direction. During the forward transfer motion the pressing force exerted by the transfer elements on the material is greater than the pressing force exerted during the return motion of the transfer elements.

Abstract: A method for the feeding of long pieces of wood into a disc chipper against a disc (3) equipped with blades in such a way that the piece of wood encounters the bladed disc at a sharp input angle, and a disc chipper. The sharp input angle is achieved by combining with the sharp inclination (.perspectiveto.) of the feeder chute (5) a sharp level slanting angle, whereupon the inclination of feeder chute (5) will be sufficient to feed wood against the blade disc.

Abstract: The present invention concerns a screening method and apparatus for sorting wood chips into three categories, namely, accept chips, overthick and/or overlong chips requiring further processing and reject fines. The chips are fed onto a disc screen. A major portion of fines and a portion of accepts fall by gravity through clearances between the discs (1) of the disc screen and a portion of the chips travels over the disc screen. Screening of chips on the disc screen is cut short before all accept chips have fallen through the disc screen. Chips travelling over the discharge end of the disc screen are routed onto a roller screen (10), whereby the remaining portion of accepts can fall by gravity through the roller screen while overthick and/or overlong chunky chips are conveyed over the discharge end of the roller screen.