Abstract: A high temperature vacuum heat treating furnace has a hot zone, including heating elements and thermal insulation, which is movable between a heating location at least partly surrounding a load space and a cooling location remote from the load space. A cooling gas plenum around the hot zone in the heating location can eject cooling gas toward a load in the load space after the hot zone is retracted. Cooling rates approximately comparable to a furnace operable at four bar pressure can thereby be obtained in a furnace rated for no more than two bar internal pressure.

Abstract: A vacuum furnace has a heating chamber heated by metal strip electric heater elements. The elements have insulated mechanical support between their ends to hold them in position in the furnace. Support is provided by a ceramic post having an internal thread in an outer end threaded onto a rod secured to a portion of the furnace. A transverse member at an inner end of the post includes a straight surface normal to the length of the post for engaging the heater element. The heater element is compliantly connected to the straight surface. One embodiment of heater element support is in the form of a T-shaped ceramic post having an internal thread in the leg of the T and a ceramic crossbar having a straight surface normal to the length of the post for receiving the heater element. Another embodiment has a ceramic post having an internal thread in the outer end of the post and a metallic crossbar having a straight surface normal to the length of the post for receiving a heater element.