FR2007268A1 - Introducing air into paper-making machine - drying section pockets - Google Patents

Abstract

Apparatus for introducing air into the 'pockets' of paper making machine drying sections. G2B. In which the drying felts are replaced by a screen belt covering the wet paper web as it passes over successive rolls in the drying section, the pockets being defined as the spaces bounded by the straight lengths of web extending from one roll to the next, the roll surface and the screen belt and its guide roll. The apparatus consists of two parallel walls running the whole width of the web, sitting in a tray-shaped base connected to a source of drying air, preferably heated, the walls being adjustable for height and lockable in any given position by means of an eccentric cam device. Much lower air pressures are required than for the drying rolls and felts, so that larger quantities can be supplied without the risk of tearing the still weak paper web. Since air is supplied at constant pressure across the whole width of the paper, more uniform drying is assured, while the air moisture content remains less than that of the web. The surfaces of the side walls are covered by rubber or the like to prevent damage to the screens with which they are in close proximity.