Power cable with metallic shielding tape and water swellable powder
AssigneePirelli Cable Corporation
InventorsFabrizio Marciano-Agostinelli, Marco Barbaro-Forleo, Paul L. Cinquemani, Michael D. Buckweitz
Life of this patent
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Abstract
A high voltage electrical power cable with a longitudinally folded, smooth or corrugated, metal strip around a plurality of layers around the conductor and a water swellable material at least at the adjacent edges of the strip. Preferably, the water swellable material is included with a polymeric material which is flowable at a temperature at least as low as 100.degree. C., the polymeric material has a 100 gram needle penetration value in the range from 50-100 tenths of a millimeter at 25.degree. C. and the water swellable material has a particle size not greater than 200 microns.
Claims34
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together and in conductive contact with adjacent wires, particles of water swellable material within any interstices in said conductor, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield of substantially constant cross-sectional radius around said insulation and a longitudinally folded strip of metal with circumferentially spaced edges around said insulation shield, said strip being corrugated transversely to its length to provide outwardly extending humps and intermediate valleys and having its edges extending longitudinally of said cable and being adjacent to each other but with a space at the face of one of said edges between it and the adjacent portion of the strip, the improvement comprising particles of a water swellable material at least in said space at the adjacent edges of said strip.
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together and in conductive contact with adjacent wires, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield of substantially constant cross-sectional radius around said insulation and a longitudinally folded strip of metal with circumferentially spaced edges around said insulation shield, said strip having its edges extending longitudinally of said cable and being adjacent to each other but with a space at the fence of one of said edges between it and the adjacent portion of the strip, the improvement comprising particles of a water swellable material at least in said space at the adjacet edges of said strip.
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together and in conductive contact with adjacent wires, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield of substantially constant cross-sectional radius around said insulation and a longitudinally folded strip of metal with circumferentially spaced edges around said insulation shield, said strip having overlapping edge portions extending longitudinally of said cable and adjacent each other but with a space at the face of one of said edges between it and the adjacent portion of the strip and being corrugated transversely of its length to provide outwardly extending humps and intermediate valleys extending circumferentially of said insulation shield and a jacket around said folded strip, the improvement comprising:
- filling compound filling any interstices in said conductor and being intermediate at least a longitudinally extending portion of said strip and said insulation shield and in said space, said filling compound comprising a polymeric material which is flowable at a temperature at least as low as 100.degree. C. and which has particles of a water swellable material in contact therewith.
A method of making an electrical power transmission cable having a plurality of layers of uninsulated wires thereby providing an outer layer of wires and an inner layer or layers of wires, said method comprising:
- bringing together said wires into conductive contact while applying flowable polymeric compound around at least the said wires forming the inner layer or layers;
- putting particles of a water swellable material having a particles size not greater than 200 microns into contact with said polymeric compound which is applied around said wires forming said inner layer or layers;
- extruding a first layer of semi-conductive material around said wires;
- extruding a layer of insulation around said layer of semi-conductive material;
- extruding a second layer of semi-conductive material of substantially constant cross-sectional radius around said layer of insulation;
- longitudinally folding a metallic strip around said second layer so as to provide overlapping edge portions extending longitudinally of the cable said edges being adjacent to each other but with a space at the face of one of said edges between it and the adjacent portion of the strip;
- and
- applying particles of a water swellable material adjacent the edge portions of said strip prior to completion of the folding of said strip so as to provide said particles at least in said space.
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together and in conductive contact with adjacent wires, particles of water swellable material within any interstices in said conductor, semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield of substantially constant cross-sectional radius around said insulation and an elongated metal element radially outwardly of said insulation shield, said element having its edges extending longitudinally of said cable and adjacent to each other but with a space at the face of one of said edges between it and the adjacent portion of the strip and the improvement compising particles of a water swellable material at least in said space at the adjacent edges of said element.
In an electrical power cable comrpising a stranded conductor formed by a plurality of wires stranded together, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield around said insulation and a longitudinally folded strip of metal around said insulation shield, said strip having its edges extending longitudinally of said cable and being adjacent to each other, and said strip being corrugated transveresely to its length to provide outwardly extending humps and intermediate valleys extending circumferentially of said insulation shield, the improvement comprising particles of a water swellable material admixed with an extrudable polymeric material and filling said humps at the interior thereof, said polymeric material having a 100 gram needle penetration value between 50 and 100 tenths of a millimeter at 25.degree. C. and said particles of water swellable material having a size not greater than 200 microns.
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield around said insulation and a longitudinally folded strip of metal around said insulation shield, said strip having overlapping edge portions extending longitudinally of said cable and being corrugated transversely of its length to provide outwardly extending humps and intermediate valleys extending circumferentially of said insulation shield and a jacket around said folded strip, the improvement comprising:
- a filling compound filling any interstices in said conductor and being intermediate at least a longitudinally extending portion of said strip and said insulaton shield, said filling compound comprising a polymeric material which is flowable at a temperature at least as low as 100.degree. C. and which has a 100 gram needle penetration value between 50 and 100 tenths of a millimeter at 25.degree. C. and which has particles of a water swellable material in contact therewith, said particles of water swellable material having a size not greater than 200 microns.
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield around said insulation and a longitudinally folded strip of metal around said insulation shield, said strip having its edges extending longitudinally of said cable and being adjacent to each other, said strip also being corrugated transversely to its length to provide outwardly extending humps and intermediate valleys extending circumferentially of said insulation shield, the improvement comprising particles of a water swellable material admixed with an extruddable polymeric material at least at the adjacent edges of said strip, the mixture of said particles and said polymeric material also filling said humps at the interior thereof.
In an electrical power cable comprising a stranded conductor formed by a plurality of wires stranded together, a semi-conductive stress control layer around said conductor, a layer of insulation around said stress control layer, a semi-conductive insulation shield around said insulation and a longitudinally folded strip of metal around said insulation shield, said strip having its edges extending longitudinally of said cable and being adjacent to each other, the improvement comprising particles of a water swellable material admixed with an extrudable polymeric material at least at the adjacent edges of said strip and within any interstices in said conductor.
Dependencies are inferred from the claim text.