Benchmark for heat recovery from the offgas duct of electric arc furnaces

Tenova's iRecovery® steam generation technology is used in many industrial plants for energy optimization. With level 1, the off-gas can be cooled down to 600°C in a steam generating off- gas duct. Level 2 enables the off-gas to be cooled down to 200°C using a waste heat boiler. The mixture of steam and water is guided into a steam drum where the steam and water are separated. While the steam is taken out, the water returns to the circuit. The German steelmaker Georgsmarienhütte GmbH (GMH) had chosen a level 1 system. After the iRecovery® duct, a water quenching tower is installed. No downstream oxygen control system is installed. iRecovery level 2 waste heat boilers are designed in such a way that the residence time is not longer than in the formerly used system. Fast quenching does not depend on water injection. The benefits of this system includes less inner corrosion, lower water consumption, lower water volume and higher safety in different emergency situation.