VORRICHTUNG UND VERFAHREN ZUM TEMPERIEREN VON WALZEN

The roller (1) is equipped both with peripheral longitudinal bores (2) and an external heat exchanger. The latter forms a closed circuit with the bores in the roller. Both carry a recirculating, thermal-control fluid. The heat exchanger is an inductor (3) with hollow electrical conductors (5). The fluid is recirculated through both the bores and the conductors. The conductors form an inductive loop (4), and all have the same clearance from the roller surface. A magnetic yoke (6) surrounds the loop. The inductor has an E-shaped cross section, the conductors being located between the limbs. A valve is included in the fluid circuit, and a heat exchanger can be connected to it. The conductor is copper or aluminum. Of two rollers in the calendar, one is electrically heated, the other is heated by thermal fluid. The ratio of internal and external heating is controlled by altering the recirculation flowrate and/or by bypassing. The inductor is designed for operation at above 200[deg]C. The roller is under programmable control. An independent claim is included for the corresponding method of controlling the roller temperature.