iRecovery System

iRecovery® technology results in effective recovery of EAF off-gas thermal energy. This energy is the biggest fraction of the primary energy input in the EAF process typically wasted away. The iRecovery® system consists in a Heat Recovery for Steam Generation (HRSG) with a radiant, Evaporative Cooled System (ECS), and convective section, the Waste Heat Boiler (WHB), which can completely process the waste gas from approx. 1700°C to 200°C. Pressurized water at boiling point feeds the ECS + WHB where it is converted into steam through the heat exchanged with the waste gas. Saturated steam the energy carrier to the different users.

iRecovery® was firstly developed for standard 100% scrap EAF basket charging processwhere the energy in the waste is almost 25% of the primary input in a standard process using about 380 kWh of electrical energy per ton of liquid steel. The iRecovery® performance is based on 180-200 Kg/tls of steam.

The well-known Tenova EAF Consteel process for continuous charging and charge pre-heating, [2], is one of the main technologies for recovering and re-using the waste gas thermal power directly in the melting process. Tenova coupled the Consteel and iRecovery® in order to improve the effectiveness of its technologies: while the high temperature thermal power contained in the waste gases, up to 800°C, is first used in scrap preheating by Consteel, the WHB is recovering the residual waste gas energy. This combination can produce about 90-140 kg/tls of steam.”