Vacuum furnace with movable hot zone

摘要

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. $$