Abstract: A disc refiner for thermo-mechanical pulping of wood chips or other fiber source for papermaking has annular refiner discs with a plurality of axially protruding radially extending curved refiner bars. Curved bars in the refiner zone should resist erosion and corrosion. Each disc has a region of bars which curve in the direction of rotation, and a region which curves away from the direction of rotation. Two identical refiner discs are mounted to rotate with respect to one another. Because of the bar curvature, processed stock experiences different angles of bar intersection as the pulp progresses from the inside of the refiner plate to the outside of the refiner plate, yielding a reduced hit on the pulp where opposed refiner bars curve in opposite directions. Where refiner bars on opposed plates curve in a like direction as they pass over one another there is a hold back action on the stock in that region.

Abstract: A disc refiner for thermo-mechanical pulping of wood chips or other fiber source for papermaking has annular refiner discs with a plurality of axially protruding radially extending curved refiner bars. Curved bars in the refiner zone should resist erosion and corrosion. Each disc has a region of bars which curve in the direction of rotation, and a region which curves away from the direction of rotation. Two identical refiner discs are mounted to rotate with respect to one another. Because of the bar curvature, processed stock experiences different angles of bar intersection as the pulp progresses from the inside of the refiner plate to the outside of the refiner plate, yielding a reduced hit on the pulp where opposed refiner bars curve in opposite directions. Where refiner bars on opposed plates curve in a like direction as they pass over one another there is a hold back action on the stock in that region.