Into the pluri-cylindrical machines, contrarily to the Yankee machine for Tissue production, the requested heaet to cause water evaporation inside the sheet, is almost given from dryer cylinders.

The air used for pocket ventilation is heated at a temperature of about 120°C throught an air/air recuperator which exploits the heat contained inside the extraction fumes of the Hood itself, and thanks to a battery system with alive steam. Where this is possible, as aid of the alive steam battery, we use battery which uses the heat contained into the condensate and into the flash steam coming from the steam plant supply of the dryer cylinders. A number of centrifugal fans are used for the inlet of the necessary air for pocket ventilation.