PCM-based energy recovery from electric arc furnaces

The problem of energy recovery from the electric arc furnace process of steel industry is addressed. During a tap to tap cycle, a significant part of the energy required for steel production is dissipated by the off-gas. The high variability of temperatures and flows, and the high concentration of dust, which characterize the production process, make the adoption of current energy recovery solutions quite difficult, both from the technological and the economical perspective. A new system is proposed exploiting the characteristics of phase change materials (PCM), in particular aluminum, to reduce the variability of off-gas temperatures and thermal powers, in order to allow an efficient energy recovery. The smoothing device is analyzed by thermo-fluid dynamic simulations in order to optimize its performance. A new boiler configuration equipped with cyclones is proposed to overcome also the problem of high dust content of the off-gas. The high recovery efficiencies, the low investment and operation costs and non-invasive plant modifications induced by the smoothing system, make the proposed PCM-based recovery system a feasible solution to reduce energy supply costs and emissions in the steel industry. (C) 2014 Elsevier Ltd. All rights reserved.