Innovation in Electric Arc Furnaces

Abstract

PrefaceSelection of innovations for each plant as well as selection of directions of further development is one of the crucial problems both for the developers and for the producers of steel in EAF. Ineffective selection leads to heavy financial losses and waste of time. In practice, this happens quite frequently.The main objective of this book is to help the readers avoid mistakes in selecting innovations and facilitate successful implementation of the selected innovations. The entire content of the book is aimed at achieving this objective. This book contains the critical analysis of the main issues related to the most widespread innovations in EAF. The simplified methods of calculations are used for quantitative assessment of innovations. These methods are explained by numerous examples. Considerable attention is given to the new directions of development which the authors consider to be the most promising.In the process of writing of the book, its content was discussed with many specialists working at metallurgical plants and for scientific research and development organizations. The authors express deep gratitude for their valuable observations and considerations.

Modeling and Validation of an Electric Arc Furnace: Part 1, Heat and Mass Transfer

“…As suggested, the arc energy transferred to the steel through conduction amounts to 15-20% of the total arc power, 75-85% of the arcs' energy is transferred to the furnace surfaces by radiation 6) and some of the energy is lost to gas and electrodes (2-5%). 3,7) In our case the energy dissipated from the arcs by conduction (Qarc) is proportional to arcs' powers and represents 20% of the total power, the energy transferred by radiation (Qarc-RAD) is assumed to represent 75% of arc power, 2.5% of the arc power heats the gas zone (Qarc-gas), while the remaining 2.5% of the energy is lost to electrodes and is thus neglected in further calculations.…”

“…where (PART 2) represents the energy provided by the burners, Kburn represents the approximate burner efficiency (0.7) 6) and together with represents the hyperbolic-tangent approximation which accounts for decreasing burner efficiency with increasing temperature of the steel. Hyperbolic-tangent burner efficiency approximation is derived from the paper of Bergman and Gottardi, 8) who suggest that the burner efficiency is decreasing proportionally to the % of the meltdown time.…”

Mathematical Modeling of Postcombustion in an Electric Arc Furnace (EAF)

“…The result of the enthalpy and capacity of CO combustion is shown in Table 12. The enthalpy is calculated by assuming that CO reacts with cold oxygen (at 298 K) at a temperature of 1800 K. The enthalpy of CO 2 is calculated at 2000 K [15]. Table 12.…”

Cisdi-Green Eaf

“…To that end, the temperature of discharged fume from EAF with conventional scrap preheating cannot be kept in a stable range; the temperature of after-burnt fume would generally rise, unable to be accurately controlled. In other words, the energy loss from fume after-burning and quenching is understood as an encroachment of the saved electric energy mostly from the scrap preheating [3] [4] . That underscores the study on how to make a cost-effective control of fume temperature downstream scrap preheating.…”