Scrap melting in continuous process rotary melting furnace Part 2 – Development of model

Abstract

A heat transfer model for scrap melting in an oxy fuel fired continuous process rotary melting furnace, which was envisioned as a replacement for the electric arc furnace in minimill steelmaking, is presented in a two-part series. The present paper describes the development, validation and predictions of the model. The model treats the furnace as three domains: the freeboard space, the liquid bath, and the refractory structure, all linked by shared boundary conditions. The model predictions indicate that a melting rate in order of 100 ton h⁻¹ can be achieved by a 4 m (inner diameter) × 16 m furnace operating with a CH₄ firing rate of 6000 nm³ h⁻¹. The thermal efficiency is ∼66%. The direct energy consumption is 620 kW h t⁻¹, which is less than the 660 kW h t⁻¹ of a typical electric arc furnace and represents a saving of ∼45% in terms of at source energy, i.e. accounting for the actual energy required for thermal generation and transmission.