Perforated roll for guiding a flexible material web

摘要

A drum for guiding a material web, in particular a paper web. The drum has a jacket and a hollow interior. A respective cover at each end of the jacket. A respective bearing journal at each cover for supporting the roll to rotate. The jacket has a plurality of passage openings for passage of air therethrough. At least one and perhaps two impellers inside the interior of the drum, each having a suction side for drawing air into the drum through the passage openings. A pressure side at the other side of the impeller. Air exits the drum from the pressure side of the impeller through passage openings and/or an opening in a cover.