Optimisation of the Energy Consumption in the Pulp Refining Operation

摘要

In paper industry, the pulp refining operation enables manufacturing a wide range ofrnfibrous suspensions (pulps) which induce different paper grades. We propose in thisrnpaper a methodology for optimizing a refining installation. A standard drainage testrn(°SR) characterizes in paper industry the refined pulp. For the papermakers, the controlrnof the °SR is consequently of primary importance since it is correlated with the end-usernpaper properties. In this research, refining trials are carried out on bleached softwoodrnKraft pulp using a laboratory disk refiner running in a batch mode and low consistencyrn(2% to 6% of mass solid fraction). The refining kinetics is analyzed by considering thernevolution of the °SR function of the net mass energy consumed. All the curves exhibitrnan S-shape. At the same net mass energy consumed, the kinetics curves may differrnconsidering the applied net power. Instead of the net power, a more general concept ofrnthe refining intensity is used here the net tangential force per crossing point. 4 values ofrnthis intensity enable differentiating the experimental trials. It has to be noted that 6rnpoints of net mass energy consumed are considered per intensity. For the covered rangernof intensity, between 1.4 and 4.3 N, the quickest refining kinetics is obtained for (44.5rn+/- 1) °SR which minimizes the required energy consumed at 3.1 kWh/(t.°SR) for arnsoftwood pulp. This numerical value is 5 to 6 times less than the industrial ratio 15-20rnkWh/(t.°SR) classically encountered in industry for printing and writing paper grades.