Abstract: A rotatable heat exchange drum is provided. This drum can be used for heating and/or cooling an elongated material. The drum includes an outer cylinder having an inner surface, and an inner cylinder within the outer cylinder, the inner cylinder having an outer surface annularly spaced from the inner surface of the outer cylinder so as to form an annular gap. The outer surface of the inner cylinder and/or the inner surface of the outer cylinder are/is provided with at least one channel extending therein, and being in communication with the annular gap between the inner and outer cylinders. The channel serves to provide a pathway over which heat exchange fluid is swirled in order to thereby prevent the formation of stagnant boundary or "confine" layers within the annular gap.