High temperature vacuum furnace

Apparatus for an electric resistance heat treating furnace including a cylindrical heat shield assembly and a planar heat shield assembly at each end of the cylindrical heat shield assembly forming an interior chamber, comprising:

• first pairs of elongated radiant energy heating units formed to be uniformly spaced in coaxial alignment around and offset from the interior of said cylindrical heat shield assembly, said units in each of said first pairs being located at mutually opposed sides of said cylindrical heat shield assembly and include parallel spaced resistance elements electrically connected in series at adjacent ends thereof;
• and
• second pairs of elongated radiant energy heating units formed to be uniformly spaced in transverse alignment and offset from the interior of each of the planar heat shield assemblies, said units of each of said second pairs being located at mutually opposed sides of each of the planar assemblies and include parallel spaced resistance elements electrically connected in series at adjacent ends thereof;
• each of said resistance elements including relatively thin flat elongate sections angularly disposed from each other for radiating energy in diverse directions into the chamber and toward the cylindrical and planar heat shield assemblies.

Apparatus for cooling an electric resistance heat-treating furnace comprising:

• a cylindrical vacuum-tight vessel with a loading door at each end for receiving a workload, said vessel including inlet and outlet ports;
• a cylindrical heat-reflecting assembly concentrically offset from the interior of said vessel defining an interior hot zone and an annular channel between said cylindrical assembly and said vessel;
• a planar heat-reflecting assembly offset from the interior of each of said loading doors defining an end channel at each end between said planar assembly and said doors;
• first radiant heating units circumferentially spaced around and offset from the interior of said cylindrical assembly;
• second radiant heating units transversely spaced and offset from the interior of the planar assemblies;
• a heat exchanger operatively connected between an inlet and an outlet port of said vessel for cooling a fluid from said outlet port;
• blower means operatively connected between said heat exchanger and said inlet port for circulating the fluid through said chamber and said channel;
• first means responsive to the temperature of the fluid at said outlet port for modulating the fluid flow only through said channels;
• and
• second means responsive to the temperature of the fluid at said outlet for modulating the fluid flow only through said chamber.