Abstract: Method and an apparatus for controlling the production of thermomechanical pulp meter chips by metering elements (9, 10) into a feed chest (2), and by feed elements (3, 7) connected to the feed chest feeds chips for refinement between thermomechanical pulp refining discs (5). Water is added to the chips prior to feeding the chips between the discs (5). Moisture content of the thermomechanical pulp is measured after the thermomechanical pulp refiner at least in a semicontinuous fashion by at least one measurement device (21, 22, 23, 24) operating on-line, and on the basis of measured moisture content, the quantity of chips and water to be metered is controlled so as to regulate the moisture content to a desired level of having a constant value by, e.g., increasing the volume of metered chips and simultaneously decreasing the quantity of fed water for an increasing trend of moisture content, and correspondingly, applying an opposite strategy to counter a decreasing trend of moisture content.

Abstract: A method for controlling a chip refiner meters chips into a chip refiner with the help of a metering device, and feeder which is adapted to the chip refiner for feeding chips between refiner disks. Water is added to the chips prior to feeding them between the refiner disks. Temperature of the axial bearing is measured, and using conventional methods, the volume of chip stock metered to the feeder means is controlled with the help of the metering device so as to regulate the temperature of the axial bearing to a constant level.

Abstract: A method for controlling a chip refiner meters chips into the chip refiner with the help of a metering device and feeder which is adapted to the chip refiner for feeding chips between refiner disks. Water is added to the chips prior to feeding them between the refiner disks. Input power to the feeder means is measured, and using conventional methods, the volume of chip stock metered to the feeder is controlled with the help of the metering device so as to regulate the input power to the feeder to constant level.

Abstract: The speed of feed movement of a piston is controlled to an essentially constant value by direct digital measurement of the actual speed, by comparing the actual value to a preset value and by compensating for differences therebetween. Variations in the piston feed pressure and in the grinding power are taken into account by means of additional signals related to these factors and added to or subtracted from the signal representing the actual value of the speed of the piston.