Modeling of Electric Arc Furnaces ( EAF ) with electromagnetic stirring
Electromagnetic stirring can play an important role in modern Electric Arc Furnaces (EAF), as they often operate far from equilibrium conditions, with tap-to-tap times of 45 minutes or less, high electric power input and significant energy additions from fuel and oxygen. Numerical modeling is used extensively in ABB’s current efforts to optimize the EAF process with electromagnetic stirring. The modeling approach uses a Finite-Element method (FEM) for computing the forces generated by the electromagnetic stirrer, whereas the resulting flow properties, heat and mass transfer in the system is computed using a Finite-Volume (FVM) flow solver. The paper presents the numerical model in greater detail and discusses some important results. We show that electromagnetic stirring gives a more than ten-fold increase of flow velocities and circulation, compared with a flow driven by natural convection alone. The global circulation created by electromagnetic stirring dramatically reduces temperature differences in the melt, thus reducing super-heating of the melt surface and risks for cold regions. Efficient mixing of chemical species, together with even temperatures, is beneficial for efficiency and controllability of the chemical reactions in the slag-metal interface.
Modeling and Optimization of the Electric Arc Furnace With Electromagnetic Stirring
Electric arc furnace (EAF) is an energy intensive process and one of major routes of steelmaking. EAF productivity and steel production cost are major concern for EAF technology development. ABB developed electromagnetic products for EAFs over 70 years ago. Over 150 units were installed worldwide with increased productivity, improved steel quality and operation safety. Since 2009, ABB has committed to the technology and product development of ArcSave, a new generation of electromagnetic stirrer for EAF application. ArcSave has been investigated through numerical simulation [1], EAF water model experiments [2] and plant test with ABB previous electromagnetic stirrer [3]. ArcSave product was released in 2014 and first was installed in a 90 ton Arc furnace. Hot test results show a significant iron yield increase and other process benefits which have been presented in the AISTech 2015 conference [4].
SR topography of plastically deformed Fe-Si bicrystals - observation in situ and post mortem
SR reflection topography was applied to study the interaction of slip dislocations with the grain boundaries in Fe-4at%Si bicrystals deformed by compression. Three experimental settings with either a white or monochromatic beam were used and the corresponding orientation contrast analysed. Dislocation transmission through the grain boundary was observed in bicrystals with favourable geometry of the slip systems.