Helical Grooving of Pulpstones: A Mill Scale Evaluation, 1991 International Mechanical Pulping Conference Proceedings

A mill scale test was performed to evaluate the effect of deep helical surface grooves on the operating characteristics of pulpstones. The production rate, energy consumption and pulp properties of 3 grooved pulpstones were compared to 3 pulpstones having conventional surface treatment. Daily pit stock composites were collected for a period of 30 days. Individual stone production was determined by pocket counts. Specific energies for individual stones were calculated daily. Each composite was measured for freeness, tear index, burst index, breaking length, and scattering coefficient. The results were tabulated, studied and graphed against: (1) days since sharpening; (2) pit freeness; (3) specific energy and (4) stone production. Normal mill monitoring of pulp quality showed no difference in debris levels in the combined stock leaving the screen room. Over the 30 day period, production rate was increased, specific energy was lower with virtually no deterioration in physical or optical pulp properties.