A high-temperature gas heater

A crucible heater which employs graphite chips as the heating element for use in supersonic gasdynamic research is described. Gas passes through the graphite chip bed, which is heated by a graphite electrode through which an electric current is run. The electrode is a hollow perforated plate which filters particles and allows the passage of gas. Operating experience to date has been with nitrogen heated from cold to 1400 C in 15 s, and temperatures up to 2500 C are noted to be possible. The chamber permits continuous variation of pressure and temperature over a broad range, is tolerant of oxidants, and can be used with ferrochrome or silicon carbide chips instead of graphite.