Electric cartridge heater

摘要

A cartridge heater includes an inner casing in which a heating element is accommodated. This inner casing is surrounded by an coaxially arranged outer casing of larger diameter so that an annular space is defined between the inner and outer casings. In the space a helical coolant piping is arranged, embedded in a highly heat-conductive substance of granular and/or pulverulent form so as to allow excess heat to be carried away.