Small cartridge heater

摘要

A cylindrical core of a ceramic such as alumina (Al2O3) has grooves in the form of a double lead thread. A coil of Nichrome V is placed in the grooves, starting in one lead of the thread and returning in the other. A split ring of a ceramic such as beryllia surrounds the core. The heater is enclosed in a housing of a metal such as Inconel 600. The entire cartridge is only one inch long and 3/16 inch diameter. It is used as a catalyst bed heater for a satellite thruster.