Heat Furnace Coil

A tube furnace is an electric heating device used to conduct syntheses and purifications of inorganic compounds and occasionally in organic synthesis. One possible design consists heating coils that are embedded as a spring on ceramic tube; such type can with stand 1200 ⁰C continuous temperature in a thermally insulated chamber. Temperature is controlled via feedback from a thermocouple.
For temperature more than 1200⁰C ceramic tube inside insulated chamber is heated with rod type or U type Silicon carbide heating elements, such furnace can withstand maximum temperature of 1500⁰C. Advanced materials in the heating elements, such as molybdenum disilicide offered in certain models can now produce working temperatures up to 1800 °C.
More elaborate tube furnaces have two (or more) heating zones useful for transport experiments and also to achieve more uniform heat zone in middle of furnace. Some digital temperature controllers provide an RS232 interface, and permit the operator to program segments for uses like ramping, soaking, sintering, and more. This facilitates more sophisticated applications. Common material for the reaction tubes includes alumina, Pyrex, and fused quartz.