Abstract: A combustion aiding apparatus for a steel-making electric-arc-furnace characterized by installing a combustion aiding burner on a balcony having an inspection-and-working opening through which to drop tapping hole filling-agent and also by making the nozzle of said combustion aiding burner freely inserted into and withdrawn from a furnace through the inspection-and-working opening, in a conventional combustion aiding apparatus for a steel-making electric-arc-furnace of eccentric bottom tapping type.

Abstract: A cooling apparatus for electric arc furnace (EAF) electrodes, in which nozzles spray and cool the surfaces of EAF electrodes outside the furnace roof. The water spray cooling is provided around the graphite electrode columns. Water flow is controlled in a way that water running down the electrode columns is evaporated before entering the EAF-roof hole to enable maximum graphite saving and high security.

Abstract: A primary duct is provided for supplying hot waste gas from an electric furnace to a preheater bucket charged with scrap. A preheating waste gas duct connected to the bucket is branched into a discharge duct for releasing preheating waste gas from the apparatus and a recycling duct for recycling preheating waste gas to the primary duct. In the vicinity of the junction of the primary duct and the recycling duct, an air inlet is formed for supplying air into the primary duct for burning the preheating waste gas.

Abstract: A preheating apparatus for preheating the material, such as scrap, to be charged into steel making equipment with the heat of exhaust gas from the equipment. The apparatus comprises a plurality of preheating units for dischargeably accommodating the charge. The preheating units are connected together in series by ducts to pass the exhaust gas through the units in series and preheat the charge in the units.

Abstract: A cooling box adapted to be installed in the refractory wall of a steel-making arc furnace for passing a cooling medium therethrough to cool the wall. The box comprises a base plate having an inlet and an outlet for the medium, a heat receiving copper plate having a slag lodging portion over the heat receiving surface thereof and a curved portion at each of its upper and lower ends for preventing cracking against thermal and mechanical stress concentration, and a back plate disposed between the plates closer to the heat receiving plate. The back plate and the heat receiving plate define a cooling medium flow chamber in communication with the inlet and the outlet and divided by a plurality of partitions to provide a flow channel of reduced cross section over the entire area of the heat receiving plate.

Abstract: A preheating apparatus comprises a transfer duct connected to a dust collecting combustion chamber for steel making equipment, a hood fitting to the duct and shiftable to the position of one of preheating pits selectively, a bucket removably placed in each of the preheating pits and having an exhaust gas passage in its interior and openable bottom means at its bottom, and a communicating duct for holding each of the pits in communication with an outlet duct of the combustion chamber. The material to be charged into steel making equipment is placed into the bucket and preheated with exhaust gas from the combustion chamber. The apparatus assures savings in energy, improved safety and enhanced heat exchange efficiency.