To minimize damages to a work to be treated or the constituting materials in a furnace, while maintaining heating efficiency by a method wherein the heating operation is stopped immediately, when combustion gas happens to leak into a treating chamber or the like.
A vacuum heat treatment furnace 1 effects heating treatment, such as heat treatment or the like, for a work to be treated in a treating chamber 10, accommodated in a sealable vessel 2, under a vacuum atmosphere or an evacuated atmosphere. The vacuum heat treatment furnace 1 comprises a radiant tube 16, inserted into the treating chamber 10 surrounded by a heat insulating material, a pressure sensor 30 provided in the vessel 2, and valves 24, 34, 38, which are provided in pipelines 23, 27, 29 communicating with the air supplying pipe 21, as well as the air discharging pipe 26 of the tube 16 and is closable by the sensor 30.
AKUTSU KOICHI
SATO KENJIRO
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