Patent ID: 6666954
Filing Date: 2003-12-23
Classification: D21F

Abstract:
A pressing section comprising:two press rolls arranged to form at least one press nip for dewatering a fibrous material web; a first and a second dewatering belt arranged to be guided through said at least one press nip with the fibrous material web, wherein the first and second dewatering belts are positioned on opposite sides of the fibrous material web to absorb pressed-out water; a common guidance path, formed by said first and second dewatering belts guiding the fibrous material web, located after said at least one press nip, relative to a web travel direction; a separating roll; a lower one of the first and second dewatering belts being positioned below the fibrous material web and arranged to wrap said separating roll along with the fibrous material web at an end of said common guidance path; a positionably movable guide roll; an upper one of the first and second dewatering belts being positioned above the fibrous material web and arranged to be separated from the fibrous material web in a separation path, located at an end of said common guidance path, by guidance around said positionably movable guide roll, which is located downstream of said separation path; said upper dewatering belt being guided in an unsupported run from an end of said separation path to said positionably movable guide roll, and said positionably movable guide roll being located so that said unsupported run is between 20 and 80 mm; and said lower dewatering belt and the fibrous material web being arranged to wrap said separating roll subsequent to said separation path, relative to the web travel direction, at a wrapping angle of at least about 30Â°, wherein said positionably movable guide roll is movable to adjust a wedge-opening between the material web and said upper belt in order to limit the amount of air introduced into said wedge-opening, thereby improving web guidance and reducing web flutter on said lower dewatering belt.