Internally heated autoclave for metal impregnation

Claim 1

An internally heated autoclave for impregnating a porous material with molten metal comprising an outer shell having an open end and a closed end, a cover closing said open end, cooling means positioned for cooling the other periphery of said shell, the inner periphery of said shell being lined with a thermally insulating material; a metal vessel positioned concentrically within the interior of said shell and dividing said interior into two separate and isolated chambers, the first of said chambers being a heating chamber between the outer periphery of said metal vessel and said shell, and the other of said chambers being an impregnating chamber formed by said metal vessel; an impregnating vessel positioned within and supported by said metal vessel, said impregnating vessel adapted to contain said molten metal; heating means positioned within said heating chamber for heating said metal vessel and thus said molten metal; a lift means having a shaft extending through said cover and into said impregnating chamber; a dip cage attached to the lowermost end of said shaft and adapted to be raised and lowered by said lift means; a pressure source; a vacuum source; and means to selectively communicate either said pressure source or said vacuum source to said chambers, said means to communicate including pressure equalization means to equalize the pressure in said chambers.