Understanding the bubble behaviours and flow characteristics of large-capacity bottom-blowing electric arc furnace(EAF)is crucial for potential exogenous gas-induced slag foaming process and enhancement of molten bath...Understanding the bubble behaviours and flow characteristics of large-capacity bottom-blowing electric arc furnace(EAF)is crucial for potential exogenous gas-induced slag foaming process and enhancement of molten bath dynamics.A physical model and a 3D gas-slag-steel transient bottom-blowing numerical model of a 150 t EAF were established to investigate the bubble behaviour and flow characteristics throughout the molten steel bath and slag layer under bottom-blowing,with referring to gas flow rate,plug diameter,plug arrangement and injection angle.Results indicate that the average bubble sizes experience increase,dynamic stability and decrease in molten steel bath and then undergo decrease and increase after entering into slag layer for all bottom-blowing modes.The bubble numbers exhibit the opposing trends during the process.Increase in gas flow rate leads to a significant rise in average bubble size but a decrease in number,average dwelling time and the spread area of bubbles in slag layer.Increase in plug diameter causes an opposite impact.The effect of plug arrangement radii on bubbles is almost negligible.Increasing the injection angle results in an increase in bubble size and a decrease in both bubble number and dwelling time in slag layer.The slag foaming potential was discussed referring to the bubble size,number and dwelling time in slag layer.Increase in gas flow rate and plug diameters can significantly enhance the fluids flow through increasing average flow velocity,decreasing mixing time and dead zone ratio of molten bath.Plug arrangement radius and injection angle express nonlinear correlation with average flow velocity and dead zone ratio,and the plug arrangement radius of 0.5R(R represents the radius of bottom circle of EAF model)and injection angle of 15°perform better in enhancing dynamics of molten bath.A group of bottom-blowing parameters are proposed to achieve better comprehensive performance of bubble-induced slag foaming and molten bath dynamics.展开更多
The electric arc furnace(EAF)offers advantages in energy savings,environmental protection,and high efficiency by using scrap as the primary charge and utilizing a high-temperature electric arc as the main heat source ...The electric arc furnace(EAF)offers advantages in energy savings,environmental protection,and high efficiency by using scrap as the primary charge and utilizing a high-temperature electric arc as the main heat source for steel smelting.The improvement of EAF smelting efficiency is primarily influenced by three key factors:the heat transfer efficiency of the electric arc,the intensity of molten pool stirring,and the melting rate of scrap.The arc heat transfer efficiency determines the energy input efficiency and the maximum smelting temperature of the EAF.Molten pool stirring intensity plays a crucial role in ensuring uniformity in temperature,composition,and flow within the furnace,preventing the formation of dead zones.The scrap melting rate is a decisive factor in EAF smelting efficiency,largely governed by the coupling of heat and mass transfer.Thus,understanding not only the rapid melting mechanism of scrap but also the impact of arc heat transfer and molten pool stirring is essential to optimizing the smelting process.Advancing research in these areas is critical for shortening the EAF smelting cycle,reducing energy consumption,lowering costs,and improving resource utilization.Therefore,recent achievements and development trends in fundamental research on enhancing EAF smelting efficiency were summarized.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52374317).
文摘Understanding the bubble behaviours and flow characteristics of large-capacity bottom-blowing electric arc furnace(EAF)is crucial for potential exogenous gas-induced slag foaming process and enhancement of molten bath dynamics.A physical model and a 3D gas-slag-steel transient bottom-blowing numerical model of a 150 t EAF were established to investigate the bubble behaviour and flow characteristics throughout the molten steel bath and slag layer under bottom-blowing,with referring to gas flow rate,plug diameter,plug arrangement and injection angle.Results indicate that the average bubble sizes experience increase,dynamic stability and decrease in molten steel bath and then undergo decrease and increase after entering into slag layer for all bottom-blowing modes.The bubble numbers exhibit the opposing trends during the process.Increase in gas flow rate leads to a significant rise in average bubble size but a decrease in number,average dwelling time and the spread area of bubbles in slag layer.Increase in plug diameter causes an opposite impact.The effect of plug arrangement radii on bubbles is almost negligible.Increasing the injection angle results in an increase in bubble size and a decrease in both bubble number and dwelling time in slag layer.The slag foaming potential was discussed referring to the bubble size,number and dwelling time in slag layer.Increase in gas flow rate and plug diameters can significantly enhance the fluids flow through increasing average flow velocity,decreasing mixing time and dead zone ratio of molten bath.Plug arrangement radius and injection angle express nonlinear correlation with average flow velocity and dead zone ratio,and the plug arrangement radius of 0.5R(R represents the radius of bottom circle of EAF model)and injection angle of 15°perform better in enhancing dynamics of molten bath.A group of bottom-blowing parameters are proposed to achieve better comprehensive performance of bubble-induced slag foaming and molten bath dynamics.
基金supported by National Key R&D Program of China(Grant No.2022YFC3901403)China Baowu Low Carbon Metallurgy Innovation Foundation(Grant No.BWLCF202211)Program of Introducing Talents of Discipline to Universities(Grant No.B21001).
文摘The electric arc furnace(EAF)offers advantages in energy savings,environmental protection,and high efficiency by using scrap as the primary charge and utilizing a high-temperature electric arc as the main heat source for steel smelting.The improvement of EAF smelting efficiency is primarily influenced by three key factors:the heat transfer efficiency of the electric arc,the intensity of molten pool stirring,and the melting rate of scrap.The arc heat transfer efficiency determines the energy input efficiency and the maximum smelting temperature of the EAF.Molten pool stirring intensity plays a crucial role in ensuring uniformity in temperature,composition,and flow within the furnace,preventing the formation of dead zones.The scrap melting rate is a decisive factor in EAF smelting efficiency,largely governed by the coupling of heat and mass transfer.Thus,understanding not only the rapid melting mechanism of scrap but also the impact of arc heat transfer and molten pool stirring is essential to optimizing the smelting process.Advancing research in these areas is critical for shortening the EAF smelting cycle,reducing energy consumption,lowering costs,and improving resource utilization.Therefore,recent achievements and development trends in fundamental research on enhancing EAF smelting efficiency were summarized.
