Air lock tubes for arc electrodes in vacuum melting plant - where each tube has telescopic upper portion with inflatable ring seal surrounding electrode

摘要

On the roof of a vacuum chamber employed in the metallurgical industry are air lock tubes, each of which has a telescopic upper portion. Each tube is used to surround an electrode; and the upper portion includes an inflatable ring seal forming a vacuum-tight joint round the upper end of an electrode. Each electrode consists of several coaxial sections, and is progressively lowered into the chamber via a hoist which includes an electrode contact clamp. The inflatable ring seal is pref. a hose made of elastomer, esp. neoprene, and reinforced by fibres. The electrodes gradually burn away in the chamber, and must therefore be continuously or periodically lowered into the chamber. The invention provides a simple method for adding new electrode sections.