Energy efficient solutions for EAF steelmaking

Abstract

Purpose: To review an advanced solutions to improve the energy efficiency of electric arc furnace (EAF), and presentation of own new efficient low-cost solutions with regard to needs of electrometallurgical complex of Ukraine. Design/methodology/approach: Numerical simulation and industrial experiment is used. The patterns and parameters of heat and mass transfer processes, hydromechanics in a steelmaking bath of an arc furnace, thermal operation of water-cooled elements and gas dynamics in EAF workspace, are the subject scope of the paper. Findings: Energy-efficient solutions for steelmaking: bath geometry, design features of water-cooled elements (WCE), distributed aspiration system, and the mid-temperature scrap preheating. Research limitations/implications: Influence of the bath depth on heat and mass transfer and heat loss by radiation; influence of the spatial structure of WCE on heat loss by radiation; the dispersion of aspiration on the amount of fugitive emissions through electrode gaps are established. Practical implications: Grounds to improve EAF melting space, water-cooled elements, aspiration system and utilization of energy loss are obtained. Use of the set of solutions in 120-ton EAF can reduce energy consumption by 56-68 kWh/ton. Originality/value: The new concepts of deep steelmaking bath, WCE with spatial structure and system of dispersed aspiration of the EAF are elaborated.

Methods to optimize energy consumption in Conarc furnaces

“…Hence, as per the analysis [3], which critically analysed the energy efficiency for carrying out various functions in steelmaking, it was observed that most of the supplied energy is required for heating the raw materials, and only a tiny amount of the energy is utilized for melting. Furthermore, electrical energy is preferably used for overheating the charge, while chemical energy is used for heating and melting [28]. From Fig.…”

Electric Arc Furnace Stirring: A Review

“…Timoshenko et al [80][81][82] has reported numerical modeling results using BGI, changing the height/diameter ratio of the EAF. Their results indicate that by increasing the H/D ratio from 0.18 to 0.33, the time to heat the liquid from 1500 to 1650 °C decreases by about 12-16%.…”

Energy-efficient solutions of foundry class steelmaking electric arc furnace

“…where F in is the in ner surface of the workspace, m 2 ) in dynamic lining layer thick ness d = 0.12 m and thermal conductivity l r = 2.9 W/(m ⋅ K) at a temperature difference between working surface and quasi static layer ΔT r = 1200 K, according to [9] 3 10 .…”

“…Insufficient energy efficiency of the EAF is associated with the notion of technological efficiency of shallow flat bath with a shape factor (ratio of diameter to depth) m = 5.5-4.5, in con trast with a "deep" bath in converter or ladle furnace unit, hav ing m ≈ 1. Studies [10] have shown the opportunity in reducing of radiation energy loss in the EAF of "large" metallurgy by 8.5-49 % in different conditions due to decrease in m up to 2.5-1.8. The possibilities of steel refining remain no lower than in a furnace with traditional bath geometry, despite re duction of metalslag interface, due to intensification of heat and mass transfer processes under conditions of pneumatic mixing in a "deep" bath.…”

“…Energy losses and refractory consumption. When assessing energy losses in the EAF the components (5,(10)(11)(12), the costs of heat accumulation (19) minus the enthalpy of preloaded scrap (20), taking into account the time of its exertion in the daily working cycle, are considered. It is assumed that energy loss with cooling water (5) takes place in the technological (18) and during half of the energy (8) period.…”