Guide roll for a porous belt

摘要

A guide roll for a porous belt, for instance for the drying wire of a paper machine, is described. A perforated roll shell rotates about a stationary air guide box. The guide box has two air chambers which extend across the length of the guide roll. One air chamber serves the discharge of blowing air and the other air chamber serves the intake and removal of suction air. Contained between the air guide box and the roll shell is an annular space in which a blowing zone and a suction zone are defined by longitudinal seals. Considering that blowing air and suction air may have different temperatures, the two air chambers of the air guide box are movable axially relative to each other.