Furnace for the high temperature-high pressure treatment of materials which includes pressure medium circulation channels

Claim 1

In a furnace for the isostatic hot pressing of a workpiece which comprises: a hollow cylinder; separate end closures for sealing the open ends of the pressure cylinder, the end closures projecting into the cylinder; heating members positioned within the pressure cylinder defining therewithin a furnace space; and an insulated casing surrounding the furnace space and the heating members, the insulated casing including an insulating sheath supported at one end by a first of the separate end closures; the improvement wherein; said insulating sheath is fixedly connected at said one end to said first end closure in a gas-tight fashion, and in such an orientation to provide a gap between itself and the inner wall of the hollow pressure cylinder; said insulating sheath includes a channel means therein at the end thereof opposite to the end connected to said first end closure so as to provide fluid communication between said furnace space and said gap; and said first end closure includes means for providing two paths for pressure gas communication therethrough, one path to supply pressure gas to said furnace space and one path to provide pressure gas exit from said gap and thus, together with said channel means, provide circulation of said pressure gas to cool same, and pressure gas supply means for said two paths, said supply means including a valve means.