Development of pulp properties within refiner plate gap in energy efficient and cutting processes

Pilot scale 1st and 2nd stage TMP refining trials with three rotor plate patterns were classified as energy saving or fiber cutting according to the tensile index to specific energy consumption relation. The temperature and power dissipation profiles across the plate gap were determined and the pulp samples taken from different radii of the plate gap were analysed. Depending on the plate pattern and process conditions the pulp properties developed at different radial regions. Also the rate and the magnitude of the change varied. Back flow was evidence to affect the pulp in the inner parts of the plate gap. In the best cases the development of pulp quality continued across the plate gap, but often the development slowed or turned unbeneficial at certain radius of the refining area. A slightly increased temperature level across the radial profile and a steadily increasing cumulative power dissipation profile across the refiner plate gap gave the best energy-quality relationship.