Abstract: A method of refining fibrous material under predetermined conditions by the help of relatively rotating refining means. The material is during refining passed from the inner circumference of the refining means to their outer circumference and is thereby exposed to bending forces and axial forces. At least two variables of the refining process, such as power and gap width are measured. The measured values of the variables and their relation are used to compare them with the set point values of the predetermined refining conditions for these variables to create control signals for positioning devices for the refining means, thereby returning the refining process to the aforementioned predetermined conditions and keeping these dependent variables constantly at these conditions.

Abstract: Method and apparatus for coordinating the rate of feed and the moisture content of the pulp material to the heat quotients of the mechanical energy input in a refiner system in which the moisture-containing pulp material is introduced at an adjustable rate of feed into the central portion of an axially adjustable grinding space defined between a pair of grinding discs which rotate relative to one another within a closed housing and in which grinding space the material is propelled by centrifugal force created by the rotation of the discs in an annular radial path toward the periphery of the discs while being subjected to a grinding operation in an environment of steam generated by the heat produced by friction in the grinding space.