Paper mill drying and surface treatment calender drum has elastic sleeve made of an electrical conductor and rotating in close proximity to induction heater

摘要

A paper mill has a heat-treatment calender drum with a mantle (3) bearing an elastic sleeve (4). The elastic sleeve is made of an electrical conductor and rotates in close radial proximity to an induction heating assembly (12). The elastic sleeve has a permeability greater than one. The drum mantle (3) permeability is less than that of the sleeve. The induction heating (12) unit has two or more loops (18, 19) parallel to the drum axis of rotation and forming an E-shaped yoke (14) as seen in cross sectional view. Inductor operation is controlled by a regulator unit (22) coupled to temperature sensors (21, 23, 24).