PURPOSE: A working liquid circling structure of a heat roller is to reduce the energy consumed by the heat roller at the standby time. CONSTITUTION: A heat roller(10) comprises an outer roller-sided sheath(11) made of stainless steel or aluminum, an end plate(12) attached both ends of the sheath to form a sealed cavity filled with a working liquid and a vapor of the working liquid. A heater-sided sheath(13) is provided in its inside with a heater lamp(15). A space formed by the heater-sided sheath and the heater lamp is filled with a thermal greese to enhance the heat transfer. The inside of the heat roller is provided with a wick(14) and a working liquid cycling device(16) for returning the working liquid to the wick. The wick encloses the heater-sided sheath and is concentric with the heater-sided sheath about a rotating shaft(20).
