HEATED ROLLER WITH INTEGRAL HEAT PIPE

摘要

A heat transfer roller (10) in a machine for coating, printing, copying or heating a web, has a hollow cylindrical roller core (11) and a metal sleeve (15) for conducting heat to or from an object contacting an outer surface (17) of the roller (10). A ring-shaped cavity (21) for receiving a heat transfer medium (26) is formed between the cylindrical roller core (11) and the sleeve (15) and extends the length of the roller (10) excluding portions (22) on respective ends. Cartridge heaters (20) are provided for heating the outer wall of the core (11) to further heat the heat transfer medium (26) in the heat pipe cavity (21). The ring-shaped cavity (21) is divided into sector compartments (23) by longitudinally extending flow restriction elements (24, 25b). Wicking material (25, 25b) is disposed in respective compartments (23). The wicking material (25, 25b) and flow restriction elements (24, 25b) hold a portion of the heat transfer medium (26) in the compartments (23, 25b) while also allowing a portion of the heat transfer medium (26) to move circumferentially around the roller (10) to make temperature more consistent across the outer surface (17) of the roller (10).