Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0063—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing waste materials, e.g. slags
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
  • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
  • H01B3/08—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances quartz; glass; glass wool; slag wool; vitreous enamels
  • H01B3/087—Chemical composition of glass
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
  • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
  • H01B3/12—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances ceramics
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
  • H02G5/00—Installations of bus-bars
  • H02G5/06—Totally-enclosed installations, e.g. in metal casings
  • H02G5/066—Devices for maintaining distance between conductor and enclosure

Definitions

• the present invention relates to utilization as electrical insulator of a glass-ceramic material made from blast furnace slag.
• an underground tube cable generally has an effective service length of at least 50 to 100 years, and to realize this aim v e ry high demands must be put on all details forming part of the cable, i.a. the required insulators which normally will not be replaced in the cable during the said period of time because of the highly complicated working moments associated with such a replacement. Therefore, in order to satisfy the high demands the insulators must have the following properties:
• the insulators have been made mainly from ceramic materials such as porcelain, of glass and of various epoxy compositions.
• the insulators consisting of epoxy material have proved to be those which are best suited for utilization in tube cables and tube capsules.
• Such insulators of epoxy material are manufactured by moulding, but the manufacturing process is highly complicated.
• the main object of the invention is to provide an electrical insulator which satisfies the demands set forth in the introductory part of this description, especial regard being taken to the requirement of resistance against ageing, simultaneously as the insulator is cheap to manufacture.
• This is rendered possible, according to the invention, by utilization as electrical insulator of a glass- ceramic material obtained from blast furnace slag, said glass-ceramic material having a content of CaO exceeding or equalling 10 per cent by weight, and preferably amounting to approximately 22 per cent by weight, the electrical insulator forming a pin insulator in a gas-insulated tube cable or tube capsule intended for high voltage.
• Glass- ceramic material or so-called glass-ceramics of the stated kind have proved to satisfy the aforestated demands on insulator material equally well as conventional glass- ceramic materials having a lower content of CaO and . produced from molten glass.
• As a starting material for glass-ceramic materials intended for insulators there is thus utilized extremely cheap so-called low-grade blast furnace slag which is intermixed with a suitable quantity, determinable in advance, of silica, Si0 2 , and treated in a controlled process utilizing high temperatur and high pressure.
• a material produced in this way and known under the denomination "Slaggsital" has the fol lowing particu lars:
• V-notch value 2.8 4.0 kgcms/cm 2
• the above-mentioned "Slaggsital" material has earlier been produced mainly in the shape of plates and discs and has been utilized as covering material in the building industry and as grinding material in the mining industry and the iron and steel industry and in the coal industry and also as acid-proof lining in the chemical industry.
• Figure 1 is a side view of a tube cable section which is partly cut up for the purpose of improved illustration
• Figure 2 is a sectional view on an enlarged scale of the tube cable shown in Figure 1.
• the tube cable consists of a sleeve which may be composed of an exterior part 10 and a shielding interior part 12. Disposed within the sleeve are three tubular conductors 14 of aluminium for three-phase operation which are applied symmetrically with a spacing from one another and the encasing sleeve, pin insulators 16 constructed in accordance with the principles of the invention and disposed in spaced relationship along the conductor units serving as spacing members. The ends of the cable section are closed by insulators also made according to the invention in the shape of end discs 18.
• the prefabricated tube cable sections can already in connection with the fabrication be filled with insulating medium up to operation pressure. When joining the sections together in the ground a minor quantity only of insulating medium need to be added. Alternately, all insulating medium may, of course, be supplied in one operation in connection with the mounting of the tube cable.
• the pin insulators 16 are directly secured onto the cable sleeve or (not shown), they may be mounted on a ring member which is inserted into the said sleeve.
• the insulating medium between the conductors 14 an t e conductors and the sleeve 10, 12 may consist of e.g. sulfur hexafloride, SF 6 , or gaseous nitrogen, N 2 , or a mixture of said gases. Oil may also be used in some cases.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Dispersion Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Insulators (AREA)
• Glass Compositions (AREA)

Applications Claiming Priority (2)

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• 1978
  • 1978-03-10 SE SE7802801A patent/SE7802801L/xx unknown
• 1979
  • 1979-03-09 WO PCT/SE1979/000050 patent/WO1979000737A1/en unknown
  • 1979-03-09 JP JP50048079A patent/JPS55500150A/ja active Pending
  • 1979-10-09 EP EP79901151A patent/EP0012772A1/de not_active Withdrawn
  • 1979-10-24 DK DK448579A patent/DK448579A/da unknown

Non-Patent Citations (1)

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