Power-gap relationships in low consistency refining

Jorge Enrique Rubiano Berna; Mark Martinez; James Olson

doi:10.1515/npprj-2018-0039

Power-gap relationships in low consistency refining

Nord Pulp Paper Res J. 2019 Mar 26;34(1):36-45. doi: 10.1515/npprj-2018-0039. Epub 2019 Feb 1.

Authors

Jorge Enrique Rubiano Berna¹, Mark Martinez¹, James Olson²

Affiliations

¹ Chemical and Biological Engineering, University of British Columbia, Vancouver, Canada.
² Mechanical Engineering, University of British Columbia, Vancouver, Canada.

Abstract

Distance between stationary and rotating refining plates, gap, has a direct and significant impact on refining power. Gap is almost universally used to control power in low consistency refining operations. The relationship between power and gap are affected by refiner size, pulp type, plate pattern and refining conditions. In this study, a correlation was developed to describe the power-gap relationships at a wide range of refining conditions and furnish. The correlation was developed using pilot-scale refining data of mechanical pulps. Results showed that a properly defined dimensionless power number is suitable to describe refining power as well as to compare different refiners under the same grounds. The developed correlation was also used to predict mill-scale refining data showing good agreement with between predicted and measured values. Finally, experimental data from force sensor measurements supports the correlation's theoretical assumptions.

Keywords: energy consumption; gap; low consistency refining; mechanical pulp; refining power.

Grants and funding

This work was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) Collaborative Research and Development (CRD) grant CRDPJ 437223-12 and the support of the industrial partners AB Enzymes, Alberta Newsprint Company, Andritz, BC Hydro, Canfor, Catalyst Paper, FPInnovations, Holmen, Meadow Lake Pulp (Paper Excellence), Millar Western, NORPAC, West Fraser, Westcan Engineering and Winstone Pulp International who are thanked for their support.