Patent ID: 8869989

Claim:
A rotor for a pressure screening apparatus for screening a pulp suspension, the apparatus including a housing, a screen in the housing having an inlet surface and an outlet surface, a stock inlet in the housing, a stock outlet in the housing for receiving screened fibers passing through the screen, and a rejects outlet in the housing for receiving reject material from the inlet surface of the screen, the rotor being adapted for mounting for rotation within the screen, and for defining an annular screening space between the rotor and the screen so that the pulp suspension flows into the screening space, with accepted pulp passing through the screen to the stock outlet and rejected pulp passing along the screen inlet surface in a screening flow direction to the rejects outlet, the rotor having an interior, and an exterior with pressure impulse protuberances thereon for rotation with the rotor in close proximity to the inlet surface, the stock inlet communicating with the screening space and the rotor interior, so that the stock inlet directs the pulp suspension to one end of the rotor, where it enters the screening space and the interior of the rotor, the rotor further having at least one opening extending in the screening flow direction from its interior to its exterior for over at least a fourth of screening flow length of the rotor for admitting a substantial portion of pulp suspension from the stock inlet and the rotor interior into the screening space.