Abstract: A method and an apparatus which defines the amount of wood material present in a bark flow and controls a debarking process on the basis of the data to reduce wood losses in the debarking process. In accordance with the invention, the bark flow is imaged by a camera and an image processing unit processes the image by using different whitenesses of the picture elements or pixels of the image as a basis for defining programmatically the amount of wood material in the bark flow. The image processing unit is adapted to produce an output signal for controlling the debarking process. In addition, the invention also provides a method and an apparatus which defines the amount of wood material in a bark flow being moved to a combustion process and controls the combustion process on the basis of the data.

Abstract: An apparatus for reducing the oversized fraction of chips, especially the overthick fraction, which apparatus comprises a rotatingly fitted disc-like rotor part (1) to which is attached a number of chipping blades (2), and a fixed stator part (3) surrounding the rotor part (1), to which stator part is attached a number of counter blades (4), the blades (2) and counter blades (4) being arranged in chipping chambers (5), through which the chips to be reduced are arranged to travel outward with respect to the rotating shaft (6) of the rotor part (1). The counter blades (4) are fitted in a position substantially deviating from the radial direction of the rotating shaft (6), when viewed on the vertical plane with respect to the rotating shaft (6) of the rotor part (1).

Abstract: An apparatus for removing bark from a wood and bark containing log flow. The apparatus includes a number of bark separation units, each of the bark separation units comprising an aggregate of a toothed disc mounted on a first disc shaft and a smooth-surface disc mounted on a second disc shaft. The disc shafts are set crosswise relative to a feeding direction A applied to the log flow by the toothed disc upon the rotation thereof and at a distance from each other. The toothed disc and the substantially smooth-surface disc of a bark separation unit are set in a staggered fashion relative to each other in the axial direction of the disc shafts.

Abstract: Method and apparatus for preventing or releasing a blockage occurring in a flow of tree trunks supplied to a wood chipper via a feed hopper and for securing an uninterrupted flow of timber to the chipper. At least one lifting arm is insertable to project through an opening defined in a hopper. The lifting arm is inserted to raise tree trunks wedged in the hopper and release blockages. The duration of the lifting arm insertion is controlled momentarily for limiting the amount of tree trunks supplied to the chipper.

Abstract: A disc for a disc chipper which is adapted to rotate upon a chipper shaft is provided with a number of tools for producing chips and includes two or more sector-shaped blocks.

Abstract: A tool wheel rotatably mounted in a disc chipper. The tool wheel includes a plurality of chip outlets. Each chip outlet comprises an elongated aperture extending through the tool wheel. At least one of the ends of the chip outlet is integrally made in the basic material of the tool wheel in a beveled fashion relative to the center axis of the tool wheel.

Abstract: An improved strander, and methods of operating the same, alternately delivers material into a housing element through at least two feeding points so that material fed through the first feeding point can be stranded during movement of the housing element in a first direction. Material fed into the strander through the second feeding point can be stranded by the housing element on its return movement in a second direction. Thus, the stranding process can continue nearly continuously throughout each working cycle.