Patent ID: 6821390
Filing Date: 2004-11-23
Classification: D21F

Abstract:
Apparatus for controlling quality parameters of a pulp sheet in a dewatering section of plants for producing paper, tissue or pulp from a pulp suspension, the quality parameters including basis weight cross-profile, formation, and fiber direction, the apparatus comprising at least one headbox, each headbox defining a pulp suspension flow path, each headbox including:a suspension feed device; a distribution device comprising a distribution chamber adapted for discharging the pulp suspension from the headbox, the distribution chamber extending laterally across the flow path from a first side to a second side, the first and second sides of the distribution chamber defining a sheet width; and a turbulence-generating chamber adapted for receiving the pulp suspension from the feed device, the turbulence-generating chamber extending laterally across the flow path from a first side to a second side and including a first peripheral zone extending laterally from the first side of the turbulence-generating chamber to the first side of the distribution chamber, a second peripheral zone extending laterally from the second side of the turbulence-generating chamber to the second side of the distribution chamber, and a plurality of pipes extending in the direction of the flow path, each of the peripheral zones having discharge means for discharging at least a portion of the pulp suspension in the associated peripheral zone from the distribution device, and drainage means for discharging excess suspension from the distribution device.