| 摘要 |
<p>A hydrodynamic device for generating negative pressure excursions in a pulp slurry during fine screening, includes at least one half-foil member (123) disposed on a substantially cylindrical outer surface of a rotor (121). The rotor (121) is mounted within and co-axial with a substantially cylindrical screen (95) having a circumferentially continuous apertured zone to define an annular screening chamber (93) between the rotor (121) and the screen (95). The half-foil member (123) is collectively at least axially co-extensive with the apertured zone and has a leading edge which, also collectively, is inclined at a spiral angle (33) relative to the axis of the rotor (121) such that, in one embodiment, during rotation, the leading edge of the half-foil member (123) conducts large particles downwardly through the screening chamber (93). A selection of hydrodynamic foil configurations is provided in order to adapt to a wide range of pulp types and screening conditions.</p> |
