Suction roll, especially for a paper web drier

摘要

The suction roll, especially for a paper web drier, comprises a perforated roll shell containing therein an internal chamber partitioned by a wall member transversely arranged with respect to the lengthwise axis of the suction roll. A connection flow communicates the interior of the suction roll with a suction device, preferably a vacuum pump. At least one blade or vane within the suction roll at least reduces or prevents a possibly arising rotational or cyclone-like flow. Thus, the pressure differential brought about by the suction device can be completely used for creating the suction action and for fixing the paper web at the suction roll. This rotational or cyclone-like flow particularly occurs when the suction action is applied through a hollow shaft or duct.