Abstract: A screen for the screening of pulp suspensions is disclosed, including a screen basket, a rotor for providing pressure and suction pulses in the suspension to be screened along the screen basket, and a dilution liquid header for supplying dilution liquid to counteract thickening of the suspension during operation. The header forms a tubular channel, which divides the screen basket into at least two parts, extends around the basket, and is provided with a plurality of dilution ejection nozzles. Each ejection nozzle forms a channel including at least two channel sections; namely, an entrance channel section that opens into the channel of the header, and an exit channel section downstream of the entrance channel section, wherein the entrance channel section is substantially wider than the exit channel section.

Abstract: Screening apparatus for screening pulp suspensions is disclosed comprising a screen basket dividing the interior of the housing into a central chamber and a single outer annular chamber. The suspension is supplied to one of the outer and central chambers, so that an accept fraction passes through the screen, while a reject fraction develops that is prevented from passing through the screen. Dilution is provided by supplying diluting liquid to dilute the reject fraction. The screen basket is divided into at least two separate tubular screen sections. The dilution is provided by at least one annular element axially interconnecting the two tubular screen sections and forming a tubular dilution liquid compartment extending at least substantially around the screen basket. The annular element forms a plurality of dilution liquid ejection passages between the dilution liquid compartment and one of the outer and central chambers.

Abstract: A screen for the screening of pulp suspensions is disclosed, including a screen basket, a rotor for providing pressure and suction pulses in the suspension to be screened along the screen basket, and a dilution liquid header for supplying dilution liquid to counteract thickening of the suspension during operation. The header forms a tubular channel, which divides the screen basket into at least two parts, extends around the basket, and is provided with a plurality of dilution ejection nozzles. Each ejection nozzle forms a channel including at least two channel sections; namely, an entrance channel section that opens into the channel of the header, and an exit channel section downstream of the entrance channel section, wherein the entrance channel section is substantially wider than the exit channel section.

Abstract: A screening apparatus for screening pulp suspensions is disclosed, comprising a housing, a screen basket having a tubular mantle wall with screen apertures, the mantle wall dividing the interior of the housing into a central chamber and an outer substantially annular chamber, and a rotor arranged in the housing for providing pressure and suction pulses in the suspension to be screened along the mantle wall. At least one elongated support element connects the screen basket to the housing and at least one load sensor is arranged on the support element for sensing the load exerted by the screen basket on the support element during operation of the apparatus. A control unit controls at least one operating parameter, such as the consistency of the suspension or rotational speed of the rotor, during operation in response to signals from the load sensor.

Abstract: Screening apparatus for screening pulp suspensions is disclosed comprising a screen basket dividing the interior of the housing into a central chamber and a single outer annular chamber. The suspension is supplied to one of the outer and central chambers, so that an accept fraction passes through the screen, while a reject fraction develops that is prevented from passing through the screen. Dilution is provided by supplying diluting liquid to dilute the reject fraction. The screen basket is divided into at least two separate tubular screen sections. The dilution is provided by at least one annular element axially interconnecting the two tubular screen sections and forming a tubular dilution liquid compartment extending at least substantially around the screen basket. The annular element forms a plurality of dilution liquid ejection passages between the dilution liquid compartment and one of the outer and central chambers.