On-line refiner control

With the DAS-JAR 400 it is possible to monitor pulp quality (in Real-Time) in terms of properties that are developed during the refining process. Specific surface area, specific volume and compressibility indices are calculated from measured dynamic drainage curves for pulp with and without fines. The removal of fines is done automatically in the apparatus by a special washing step.

Comparison of pulp before and after treatment gives a measure of:

• Increase in fibrillation (surface area of washed pulps)

• Fines generation (fractional surface area of fines)

• Hydration/swelling (changes in specific volume)

• Compressibility (changes in compressibility indices)

The graph below shows an example of the change in the relative contribution of fibre, fines and fibrils on the fibre as a function of different refining levels (source: Cybermetrics):