Grit Segments In Tmp Refining. Part 1: Operating Parameters And Pulp Quality

摘要

An energy efficient technique to produce pulp fibres in TMP refining was developed by using grit material to disrupt and open the outer layers of fibres. The grits were made from self-fluxing tungsten-carbide powder and a Ni-base alloy powder, which were laser-cladded on the bar surface of a refiner segment to direct energy sharply to breakdown wood and fibres structures. The trial of grit segments was carried out on a Sunds Defibrator RGP 44 single-disc refiner performed in the first stage refining. The results showed that in the first stage refining, grit segments can disrupt and open the fibre cell walls efficiently when operated at a high refiner rotational speed of 2400 rpm. However severe shortening of the pulp fibres occurred when the energy input was above 1.3 MWh/t. The refiner equipped with grit segments operated smoothly without any adverse effects on the motor load or feeding system.