Optimizing The Chip Quality For Cooking Through Chipping & Screening Processes, 2003 Fall Technical Conference

In 1997, Andritz and Stora Enso’s Enocell mill in Finland embarked on a joint study/development project to generate improvements in pulp yield, pulp quality and consequently cost savings. Knowing that a chip supply with a narrow chip size distribution minimizes rejects in the cooking process, Enocell committed to make the changes in the existing chipping, screening and overs treatment processes to improve the chip size distribution.

During the development project, changes were made to the chipping geometry of the existing chipper. A new type of screen to replace the existing gyratory screen as well as a new machine for treatment of oversize chips in place of a rechipper was installed. The results of the study have been presented in a TAPPI Conference in Atlanta, March 5 – 6, 2002. As a part of a new Pulp Mill investment at M-B Joutseno, Andritz Wood Processing delivered a new woodyard in 2001. The installation includes two Debarking and Chipping lines, Chip and bark storages and Chip screening. The supply of a new horizontally fed HHQ-CHIPPER™, a new two-phase JETSCREEN™ screening concept and an HQ-SIZER™ for remanufacture of oversize chips are based on the earlier tests at Stora Enso’s Enocell Mill.