On techniques for measuring fiber distribution in refining zones

The objective of this research project was to develop measurement techniques to strengthen the knowledge about fiber distribution inside refining zones. A method where light extinction, dynamic pressure and temperature are simultaneously measured at high sampling rates were developed and evaluated on a pilot refiner. The characteristics of the sampled signals were clearly affected by the changes process conditions like changes in production rate, changes in dilution water feed rate and changes in plate gap. It was verified that measurement techniques like this can be used for qualitative studies on fiber distribution inside the refining zones and the results obtained strengthen several earlier hypotheses in the area.