Optimizing the Norske Powell River TMP mill for increased production and quality after a major paper mill reconfiguration

摘要

When the Norske Canada Powell River mill underwent a major structural change with the closure of the kraft and stone groundwood mills making the TMP mill the backbone of the pulp supply. The production rate had to increase substantially and the quality had to improve to keep purchased kraft and deinked pulp usage to a minimum. As a result of a concerted effort between mill and Andritz/Durametal refiner plate engineers a 20% increase in productivity was achieved along with zero kraft usage for certain paper grades. No new capital equipment was needed. New inner plate designs that promote stable chip and pulp feeding were coupled with outer plate designs that improved pulp quality. This made process optimization for consistency control and pulp strengths relatively straight forward. Long fiber content increased 20 to 30 percentage points on the B 60 refiner lines leading to greater tensile indices. Establishing the same pulp quality targets for the 5 different TMP lines ensured a stable pulp supply for the paper machines and ensured that each line and the rejects system could be continuously optimized. Energy use per ton of pulp decreased for the same pulp quality using new plate designs in two refiner lines. In sum. refiner plate design optimization coupled with an agreed overall strategy and attention to process details helped the mill adapt successfully to the change.