Abstract: A vacuum furnace with a gas manifold branching into a plurality of secondary gas manifolds, the secondary gas manifolds each including a valve that is contained in each secondary gas manifold; a hot gas plenum including an inner and an outer shell with the outer shell attached at one side to the secondary gas manifold; a series of gas restrictor walls between the inner and outer shells of the hot gas manifold that serves the purpose of dividing the plenum into a plurality of non-circumferential sectors so that the load in the plenum may be cooled from the top, bottom, left, or right side or any combination thereof.

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.

Abstract: A high temperature vacuum furnace has a circulating path external to the heating chamber for facilitating inert gas circulation during initial convection heating of a high temperature vacuum furnace. The heating chamber of the furnace and a surrounding cooling gas introduction chamber are within a metallic convection shroud in such a way that the space in between defines a heating gas circulation chamber for circulating heated inert gas during low temperature heating for accelerating the heating-up of the hot zone to its normal operating temperatures. Once the hot zone has reached a selected temperature, the inert gas is pumped out and the furnace then operates in a vacuum. Quenching is achieved by introducing cooling gas into the heating chamber via nozzles through the heating chamber walls.

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 assemblies having spaced apart mounting assemblies with a rigid bridge compliantly mounted therebetween. The heater strip is compliantly connected to the bridge. Each mounting assembly has a metal post connected to the furnace heating chamber and surrounded by a ceramic sleeve. The ceramic sleeve is surrounded by two ceramic tubes which hold an end of the bridge therebetween.