| 摘要 |
1502758 High voltage cable KABEL-UND METALLWERKE GUTEHOFFNUNGSHUTTE AG 3 Nov 1976 [3 Nov 1975] 45717/76 Heading H1A A high voltage cable insulated by gas, e.g. sulphur hexafluoride, has an inner conductor comprising a core of an alkali metal, e.g. sodium, an alloy thereof, or two or more alkali metals inside a sheath 2 of thermoplastic or elastomeric material, e.g. polyethylene, and a corrugated metal tube 3 surrounding the sheath and core; an outer metallic sheath tube 7 preferably with a thermoplastic covering 8 is coaxially spaced from the inner conductor. Tube 3 may be made from a welded copper tape and surround sheath 2 with clearance, the clearance containing an inert gas. Sheath 2 may contain soot or metal to increase its thermal and electrical conductivity. A conductive layer may be provided on sheath 2. The outer sheath 7 may, as shown, be corrugated and flexible to allow winding on drums or it may be rigid, in which case it is conveyed to the site in short lengths. In a further form the outer sheath is formed as two half shells. The inert gas in sheath 3 can be used to monitor the tightness of the sheath.
|
