| US 7,491,296 B2 | ||
| Multi-stage screening apparatus, screen basket and method for screening pulp suspensions | ||
| Börje Fredriksson, Grästorp (Sweden) | ||
| Assigned to Metso Paper, Inc., (Finland) | ||
| Appl. No. 10/512,676 PCT Filed May 08, 2003, PCT No. PCT/SE03/00746 § 371(c)(1), (2), (4) Date Jul. 07, 2005, PCT Pub. No. WO03/104549, PCT Pub. Date Dec. 18, 2003. |
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| Claims priority of application No. 0201746 (SE), filed on Jun. 07, 2002. | ||
| Prior Publication US 2006/0070924 A1, Apr. 06, 2006 | ||
| Int. Cl. D21C 7/06 (2006.01) | ||
| U.S. Cl. 162—246 [162/251; 162/55; 209/305] | 12 Claims |
| 1. A screening apparatus for screening pulp suspensions, comprising:
a housing,
a tubular screen basket dividing the interior of the housing into a central chamber and a single outer substantially annular
chamber, the screen basket including at least two separate tubular screen sections,
an inlet member for supplying a suspension to be screened into one of the central chamber and outer chamber,
an accept outlet member for discharging a developed accept fraction of the suspension that has passed through the screen basket
into said single outer substantially annular chamber,
a reject outlet member for discharging a developed reject fraction of the suspension,
a rotor arranged in the housing for providing pressure and suction pulses in the suspension to be screened along the screen
basket, and
dilution means for supplying diluting liquid to one of the central chamber or outer chamber, the dilution means including
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 forming a plurality of dilution
liquid ejection passages between the dilution liquid compartment and one of the central chamber and outer chamber.
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