| 摘要 |
The present invention is a vacuum furnace arrangement which in the preferred embodiment is generally cylindrical in shape having a hot zone chamber within, the hot zone chamber has heat insulating material secured to the inside surface of the outside wall. Secured, at several locations, to the outside wall and passing inwardly therefrom, through the heat insulating material, are a number of molybdenum rods. A heating element located in the hot zone chamber, in the preferred embodiment, is a flat strip of molybdenum, formed to approximate a circle, and which has apertures located therein with said rods passing therethrough. At each aperture there is a relatively long electrical insulator sleeve fitted over the rod to keep the rod electrically insulated from the heating element. The long sleeves in turn are held in position, within the aperture by a large disc-like shield on both ends and each of said shields in turn has an aperture through which the rod passes. Each of the shields is restrained by a pin located in the rod. In addition there are included two additional shorter sleeves of electrical insulating material disposed over said long insulating sleeve and between said disc-like shields. The shields and the two shorter sleeves act together to keep the long insulating sleeve from having vaporized material deposited thereon. The deposited material builds up and can eventually cause an electrical short circuit. In addition the shields and short sleeves act with the long sleeve to secure the heating element in place. The rod assembly can be readily disassembled and assembled to permit repairs which often become necessary in vacuum furnaces.
|
