Energy efficiency in double disc refining. Influence of intensity by segment design

The goal with this work was to study the effect of segment design on electrical energy consumption and pulp quality in double disc TMP production. Mill scale trials were performed with refiner segments from Metso, which were designed based on the fluid dynamics theory. The calculated intensity for the different segments was related to the measured pulp quality. Refining with the high intensity segments (Turbine (TM)) produced pulp with similar tensile index and a significantly higher specific light scattering coefficient at certain specific energy consumption when compared with the reference segments. One drawback with the high intensity segments was the limited operating window due to fibre cutting. The trials showed that segment performance can be modelled, which facilitates the development of new segment designs.