Measurement of the power distribution in a single-disc refiner

A vital parameter in the production of mechanical pulp through refining is the energy consumption. Until recently, the pulping industry has focused on the total energy consumed, without a full understanding of how this energy is distributed in the refiners. In this paper, two methods are suggested b y which it is possible to estimate the energy supplied at an arbitrary poin t along the disc radius on refiner segments. The methods am based on instru menting bars with strain gauges. In the first method, a bar is slotted so t hat the sensor can be viewed as consisting of a number of cantilever beams separated by slots. In the second method, the sensor consists of one contin ous bar along the disc radius. The sensors are calibrated such that influen ce coefficients are obtained for the slotted case and an influence function is obtained for the continuous one. The tangential forces are obtained dir ectly in the first method, while in the second they are given by an integra l equation which can be solved numerically. From the knowledge of the tange ntial force the power distribution can be calculated. Experimental results from the use of the slotted sensor are presented.