TMP Mill Improvements Through Advances in Single Direction Refiner Plate Design, 1999 International Mechanical Pulping Conference Proceedings

Chris Phillips

TMP Plant Supervisor

Augusta Newsprint Co.

Tina Lawton & Petri Savujärvi

J&L Fiber Services

As demands for improving energy efficiency, pulp quality, and plate life increase, the ability to select the appropriate plate design for a specific set of operating conditions becomes increasingly critical. Proper plate selection leads to improvements in the efficiency of refining energy in the manufacture of mechanical pulp. This results in cost reductions, in terms of either energy savings or a reduction in high-cost reinforcing pulp content due to improved pulp strength properties.

Single direction refiner plate design is not a new concept—it was first introduced in the late 1920’s and many attempts have been made since then to reduce specific energy consumption by taking advantage of the design’s pumping effect. The results have been promising in terms of energy savings, however these savings have usually come at the expense of unacceptably low pulp strength properties.

A solution to the energy savings/pulp strength compromise has been found with the newest generation of single direction refiner plates. These plates have been applied in the primary refiners in the TMP plant at Augusta Newsprint Company. The mill’s objective was to improve the TMP pulp burst factor so that kraft savings could be realized on the paper machines. Augusta Newsprint conducted their first trial with these plates in March 1998. Significant benefits were realized, so further evaluations were made and the mill has now adopted this new directional pattern as their standard primary refiner plate. These directional plates are contributing to improved burst strength without a corresponding decrease in tear strength. Other benefits realized by Augusta Newsprint include lower pulp freeness, reduced refiner vibration levels, improved load stability, reduced clashing of the refiner plates, and longer plate life.