Using a patented furnace advanced slag-free tapping system (FAST), Siemens VAI has developed a new electric arc furnace (EAF) concept specifically developed for melting direct reduced iron (DRI).

The Simetal EAF FAST DRI is designed for continuous melting as electrical energy input and DRI charging are continued during tapping, which shortens tap-to-tap times and reduces specific energy consumption.

Compared with conventional arc furnaces, tap-to-tap times can be cut by up to 15% and energy consumption by 20kWh/t while electrode consumption falls by 10%. The continuous supply of electrical energy during flat-bath operation not only improves productivity, but also avoids line harmonic distortions such as flicker. Using this technology, a 150t furnace can increase overall productivity by approximately 15%.

Using the furnace advanced slag-free tapping system (FAST), charging, tapping and taphole refilling are possible under power-on conditions. Slag-free tapping results in an enhanced alloys yield and better steel desulphurisation, making installation of additional burners unnecessary.

The furnace is designed for optional use in combination with Siemens’ Hot Transport System (HTS), enabling it to be fed with hot DRI at temperatures around 600°C. Due to the modular design of the new electric arc furnace, existing furnace installations can also be retrofitted with FAST DRI technology.