ballottement

CONT: The condensate that forms in the dryer cylinders is removed by a specially-designed syphon assembly .... at the high speeds of modern paper machines, the condensate layer has become so immobilized that even a very thin layer is a significant impediment to heat flow. Fortunately, the condensate layer still has some peripheral motion at high machine speed. This motion can be converted into a wave action by means of ""dryer bars"" attached axially to the interior surface of the dryer cylinder. This wave action (called ""sloshing"") greatly decreases the thermal resistance of the rimming condensate, and thus allows an increased rate of heat transfer.