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ISSN Печать: 1093-3611
ISSN Онлайн: 1940-4360
Indexed in
HIGH-POWER AC ARCS IN METALLURGICAL FURNACES
Краткое описание
A typical three-phase submerged-arc furnace for production of silicon metal and ferrosilicon has electrode currents ~ 100 kA, phase voltages ~ 100 V and total furnace power ~ 10−60 MW. The arcs burn in gas filled cavities or "craters", where the main atomic components of the plasma mixture are silicon, oxygen and carbon. Two quite different simulation models for high-current AC arcs have been developed: the simple PC based Channel Arc Model (CAM) [1], and the more sophisticated Magneto-Fluid-Dynamic (MFD) model, which is here described in some detail. The coupling between the arcs and the AC power source is described by a complete three-phase Electric Circuit Model. Modelling results for ~ 1 kA laboratory AC arcs agree satisfactorily with electrical measurements. In the industrial ~ 100 kA case the simulations clearly show that the maximum possible arc length is 5−10 cm, which is much less than previously assumed. Preliminary results with a Cathode Sub-Model for high-current AC arcs indicate that the cathode current density varies considerably during an AC period, while the spot radius remains almost constant. Model simulations further show that the influence of the easily ionised contaminants Ca and Al on arc behaviour is much less than expected. Preliminary studies of the effect of Fe vapour on the plasma properties suggest that modelling results obtained for silicon metal are also applicable to ferrosilicon furnaces. Arc splitting − i.e. several parallel arcs appearing simultaneously − may also play a role in the furnace craters.
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Saevarsdottir, G. A., Larsen, H. L., and Bakken, J. A. , Modelling of AC Arcs in Three-Phase Submerged Arc Furnaces.
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Saevarsdottir, G. A., Larsen, H. L., and Bakken, J. A. , Modelling of industrial AC arcs.
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Sevastyanenko, V G. and Bakken, J. A. , Radiative transfer in industrial thermal plasmas of complex composition.
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Larsen, H L and Bakken, J A , Modelling of industrial AC arcs.
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Neumann, W. , Pre-Electrode Processes.
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Benilov, M. S. and Marotta, A. , A model of the cathode region of atmospheric pressure arcs.
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Benilov, M. S. , The ion flux from a thermal plasma to a surface.
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Schei, A., Tuset, J. K., and Tveit, H. , Chemistry of the Si-O-C system.
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Fu You, Wang Zhen, Wang Zhiqiang, Wang Ninghui, Wang Xiaochen, Splattering Suppression for a Three-Phase AC Electric Arc Furnace in Fused Magnesia Production Based on Acoustic Signal, IEEE Transactions on Industrial Electronics, 64, 6, 2017. Crossref
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Tesfahunegn Y. A., Magnusson T., Tangstad M., Saevarsdottir G., Dynamic Current and Power Distributions in a Submerged Arc Furnace, in Materials Processing Fundamentals 2019, 2019. Crossref
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Tesfahunegn Y. A., Magnusson T., Tangstad M., Saevarsdottir G., Effect of Carbide Configuration on the Current Distribution in Submerged Arc Furnaces for Silicon Production—A Modelling Approach, in CFD Modeling and Simulation in Materials Processing 2018, 2018. Crossref