Abstract: Disclosed is a furnace wall structure which is placed in opposed relation with electrodes of a electric arc furnace and is made of copper or copper alloy in order to ensure a long service life, improved safety and a minimum thermal loss and in which a front plate which defines a heat-receiving surface exposed within the furnace is cooled by the forced circulation of cooling water.

Abstract: A roof assembly for an arc furnace is disclosed in which a furnace roof ring and a plurality of roof units are assembled together to define a roof section frustoconical in cross section and with a roof top opening, and a roof top made of an electrically insulating refractory and provided with electrode holes closely fitted into the roof top opening. Each sectionalized roof unit comprises a main body cast from cast iron or copper, and a cooling coil embedded in the main body with end sections being extended out of the upper major upper surface of the main body so as to be used as a cooling water inlet and an outlet. In order to ensure the satisfactory high-temperature strength and thermal-shock resistance, the inner major surface of the main body directed toward the inside of the furnace is partially lined with the refractory or corrugated.

Abstract: A power control system is disclosed for an electric arc or refining furnace circuit to which is supplied power directly from an independent power generating unit or units installed independently of a publicly available power supply system or any other power generating unit. Depending upon the operating conditions of the furnace, the power supply is controlled by the suitable adjustment of the generator voltage or frequency or by the combination thereof based upon the relations V = K..PHI..n where V = generator voltage, K = constant, .PHI. = flux density and n = operating speed of a prime mover mechanically coupled to each generator, and f = p.n/60 where f = frequency, and p = number of poles in each generator.