Electrical insulation device
AssigneeLaporte Industries Limited
InventorMichael Robinson
Life of this patent
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Abstract
Electrical insulation may be provided between two parts of a structure intended for exposure to high temperature radiation from a heat source, e.g. the interior wall of an electrical discharge furnace, by providing slot in the structure positioned so that the base of the slot cannot view the heat source directly. The slot may have flared lips, sides generally angled away from each other in the direction of increasing temperature, provision for a flow of gas in the same direction and provision for cooling the material bridging the base of the slot to a temperature at which it may be electrically insulating.
Claims27
A structure requiring electrical insulation between two parts thereof, a surface of the structure being intended for exposure in use in a furnace to radiation from a heat source having a temperature sufficiently elevated to cause a reduction in the electrically insulating properties of normally insulating constructional materials, characterised by the provision of a slot in the structure between the two parts thereof the slot extending from the heat exposed surface of the structure into the depth of the structure the slot being positioned and dimensioned so that the base of the slot would not view the heat source in use.
In an electrical discharge furnace having an operational temperature in excess of 1500.degree. K. and comprising spaced electrode means for striking a discharge across the interior of the furnace and furnace wall comprising at least an inner refractory surface supporting and separating said electrode means, said furnace wall being electrically non-insulating in use by virtue of the furnace operational temperature, the improvement comprising provision of electrical insulation in the furnace wall by providing a slot extending circumferentially around the wall, extending from the inner surface of the wall into the depth thereof and being positioned and dimensioned so that the base of the slot would not view the electrical discharge in use, together with means for maintaining a flow of gas in the slot towards the inner surface of the wall and means to cool the material bridging the base of the slot to not more than 675.degree. K. in use.
In an electrical discharge furnace comprising a spaced electrode means for striking a discharge across the interior of the furnace and furnace wall having an inner surface supporting and separating said electrode means, with said wall being electrically non-insulating in use at the operational temperature of the structure, the improvement comprising the provision of electrical insulation in said furnace wall by providing a slot therein, said slot being located about the circumference of said wall, extending from its inner surface to a base located at a depth of the wall, and being positioned and dimensioned so that the base would not view the electrical discharge.
Dependencies are inferred from the claim text.