Abstract: A venting system for heat treating flat material webs or films has a drying chamber with a centrally arranged single blower for supplying treatment medium, such as heated and cleaned air, to the surfaces of the flat material. Air guide channels and ducts are so arranged that a single blower is fully sufficient while still obtaining a defined suction withdrawal of the air that has contacted the flat material surfaces. Sets of blowing nozzles face the surfaces of the flat material and are arranged for cooperation with suction nozzles for the return of the treatment medium to the suction side of the blower in a substantially closed treatment medium circulating circuit.

Abstract: The invention relates to a treatment chamber for treating webs of material passing continuously through nozzle boxes extending pairwise above and below the material web and transversely across the width thereof. The treatment medium is fed from a conduit into one end of the nozzle boxes and their other end is closed. The nozzle boxes are not rigidly joined to the feed duct for the medium, rather they are separate from the medium feed duct and form an open end toward the feed duct. The open box ends are joined in a hinged manner to pivot levers, whereas the closed box ends are connected together by a cable running over a reversal guide roller. The spacings between the associated nozzle boxes are varied by pivoting the pivot levers in opposite directions. Furthermore, it is possible to lock the pivot levers and to fold-apart the nozzle boxes by actuating the cable.