Patent ID: 6101735
Filing Date: 2000-08-15
Classification: D21F

Abstract:
In a dryer section of a paper machine having single-wire draw groups, each of said single-wire draw groups including a drying wire guided in a loop, reversing cylinders arranged in said drying-wire loop and small-diameter contact drying cylinders each arranged in a gap between a pair of said reversing cylinders, a paper web being pressed by said drying wire into direct contact with said small-diameter contact drying cylinders, the improvement comprising:at least one large-diameter contact drying cylinder having a diameter greater than about 2200 mm arranged in at least one of said single-wire draw groups, the web being pressed by said drying wire of said at least one of said single-wire draw groups into direct contact with said at least one large-diameter contact drying cylinder, the diameter of each of said at least one large-diameter contact drying cylinder being greater than a diameter of said small-diameter contact drying cylinders in said at least one single-wire draw group, andan impingement-drying hood arranged to extend over a curve sector of said at least one large-diameter contact drying cylinder along which the web and said drying wire of a respective one of said at least one of said single-wire draw groups run, said hood being arranged to apply an impingement-drying effect to the web and said drying wire on said curve sector of said at least one large-diameter contact drying cylinder such that a moist boundary layer in contact with said drying wire is disintegrated and drying is promoted from a side of a face of the web opposite to the face of the web contacting said at least one large-diameter contact drying cylinder.