Single bucket charging practice with telescopic EAF roof closure

An electric arc furnace (EAF) at BasA¸tug Metallurgy was modernized in 2015 and equipped with a larger shell and bigger transformer. In the telescopic EAF the electrode column can be significantly shorter compared to other single charge EAF of similar capacity. During melting, the roof gradually slides down to the lower, fully closed position resulting in almost complete overlapping of the roof and part of the upper shell. The cycle of the telescopic movement between the upper closing position after charging and fully closed position is completed after 30-40% of the power-on-time. Some improvement related to the burner operation mode had been introduced increasing the burner power from to 4 MW. The diameter of the lower shell was increased to 8700 mm allowing for 200 t of liquid steel capacity. The new upper shell expanded the shell volume up to 330 m3. Optimized melting conditions and reduced caving phenomena drastically decreased the number of electrode breakages from 8 to 4 per month on an average.