Tubular oven

Claim 1

An oven comprising A. a tubular member having an interior layer comprised of polycrystalline silicon and an integral exterior layer comprised of phosphorous doped silicon having a specific resistance ranging from about 2 through 200 microohm centimeters, B. a pair of electrical contact means, each such contact means being in contact with a different opposed end region of said tubular member, each such contact means having 1. a plurality of circumferentially spaced adjacent graphite support members in face-to-face engagement radially with exterior layer portions of said tubular member, 2. a plurality of circumferentially spaced electrically conductive metal blocks in face-to-face engagement with radially outer surface portions of said graphite support members, and 3. clamping means securing said support members and said blocks together at and about said opposed end regions C. a thermally insulative layer circumferentially extending around said tubular member between said pair of electrical contact means but in axially spaced, adjacent relationship thereto, and D. means for cooling said pair of electrical contact means, said means for cooling comprising tubing adapted for conveying a cooling fluid in heat-exchange relationship to said metal blocks.