Patent ID: 8201990
Filing Date: 2012-06-19
Classification: B01F,D21B

Abstract:
1. An impeller for use in association with an extraction plate adapted for defibering liquid slurry stock and causing defibered material to pass through said extraction plate, said impeller comprising: a central body portion having a radially outward edge; a plurality of vanes extending outwardly from said central body portion, each vane having an inner end attached to said central body portion within said radially outward edge, and an outer end, a relatively flat extraction side, a leading face, and a trailing edge, a smoothly contoured convex airfoil trailing surface extending from said leading face to the trailing edge, the vane leading face height from the extraction side to the air foil surface being substantially constant from the vane outer end to where the vane is attached to said central body portion at the radially outward edge of the central body portion, and the vane leading face height then thereafter gradually decreasing in height from the radially outward edge of the body central portion to the airfoil surface at the vane inner end.