Power and technological features of steel melting in electric arc furnace and transferring EAF to operation with water-cooled roof designed in Moscow State Evening Metallurgical Institute

The work shows the necessity and possibility of replacement of brickwork in steelmaking electric arc furnace roof with water-cooled elements as the power introduced to the furnace increases. Such replacement results in some increase of specific energy consumption, mainly due to increase of losses during the oxidation and reduction periods of the melt, which is offset with reducing the furnace downtime for replacement of brickwork roof. Specific energy consumption decreases with increasing furnace productivity. Heat losses can also be reduced by screening the roof by injection of carbon-bearing gases to the furnace. The ways to achieve the maximum effectiveness of furnaces with water-cooled roofs by increasing productivity and changing the geometrical parameters of the furnace are also considered. The water-cooled roof designed in the Moscow State Evening Metallurgical Institute was operated at EAFs with capacities ranging from 1.5 to 200 t, and new EAFs of 175 and 320 t were put into operation in 2004-2005. Productivity indices of 230 and 320 t/hour were achived, with specific electric energy consumption of 290 and 359 kWh/t.