The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

Kai Dong - One of the best experts on this subject based on the ideXlab platform.

  • Three-phase numerical simulation of oxygen penetration and decarburisation in EAF using injection system
    Ironmaking & Steelmaking, 2020
    Co-Authors: Chun Lai He, Kai Dong, G L Jiang
    Abstract:

    The flow field of the Molten Bath and the decarburisation rate in a 150 t electrical arc furnace (EAF) are discussed based on a three-phase numerical simulation, while the furnace profile of the EAF and the installation location of oxygen lance are fixed. As shown in the results, with increasing charge mass of the Molten Bath and lowering oxygen lance height, the penetration depth of oxygen jet and the velocity of uncovered steel created by the jet increase, the area of uncovered steel becomes small and the flowrate of steel flowing through the uncovered area increases; thus, the absolute decarburisation rate increases. Simultaneously, the optimum operating mode for this EAF is with a charge mass of 150 t and an oxygen lance relative height of 0·45 m, in which the low speed area on the bottom of the EAF is the minimum and the relative decarburisation rate is the maximum; this contributes to a reduction in the tap to tap time of EAF steelmaking.

  • Technological innovations of electric arc furnace bottom-blowing in China
    Journal of Iron and Steel Research International, 2018
    Co-Authors: Yun Wang, Xuetao Wu, Kai Dong
    Abstract:

    Nowadays, in China, the bottom-blowing technique plays an important role in accelerating the Molten Bath stirring and promoting the metallurgical reactions in electric arc furnace (EAF) steelmaking. The innovations of bottom-blowing technologies in EAF steelmaking were reviewed. The optimized bottom-blowing arrangement in EAF based on the furnace structure and the position of electrodes was introduced, and the fluid flow characteristics of EAF Molten Bath with bottom-blowing were analyzed. Furthermore, bottom-blowing CO2 in EAF can facilitate the carbon–oxygen reaction reaching equilibrium and decrease the content of nitrogen in Molten steel due to its special metallurgical properties. Pulsating bottom-blowing in EAF can effectively improve the Molten Bath stirring through the action of the unsteady bottom-blowing gas streams, which could make the fluid flow field more disorderly than the steady bottom-blowing. And submerged O2 injection with CO2 in EAF can noticeably strengthen the EAF Molten Bath stirring, increase the production efficiency and improve the Molten steel quality.

  • Simulation and application of pulsating bottom-blowing in EAF steelmaking
    Ironmaking & Steelmaking, 2018
    Co-Authors: Yun Wang, Kai Dong, Xuetao Wu, Fengwu Chen
    Abstract:

    ABSTRACTPulsating bottom-blowing was proposed to strengthen the electric arc furnace (EAF) Molten Bath stirring. The fluid flow characteristics and stirring effects of different pulsating bottom-blowing modes on EAF Molten Bath were studied through water model experiments and numerical simulations. The mixing time was measured by water model experiments and the flow field characteristics of EAF Molten Bath were simulated by numerical simulations. Compared with conventional bottom-blowing, pulsating bottom-blowing can accelerate the fluid flow velocity and improve the stirring of Molten Bath. With pulsating bottom-blowing, the Molten Bath fluid flow field is more disorder, the fluid flow velocity increases and the dead zone volume decreases. Compared with EAF steelmaking with conventional bottom-blowing conditions, pulsating bottom-blowing technology can improve the metallurgical effects and the Molten steel quality in EAF steelmaking with lower FeO content of final slag, lower phosphorus content and carbo...

  • Research on the Flow Properties and Erosion Characteristics in Combined Blown Converter at Steelmaking Temperature
    CFD Modeling and Simulation in Materials Processing 2018, 2018
    Co-Authors: Shaoyan Hu, Kai Dong
    Abstract:

    The coupling stirring effect driven by top blown supersonic jets and bottom blown jets plays a crucial role in converter Bath movement. Based on numerical simulation, jet-Bath interactions inside a 110-ton commercial converter at room temperature and at steelmaking temperature were compared. Penetration depth and flow velocity in Molten Bath are larger at steelmaking temperature because the velocity attenuation of supersonic jet is suppressed. The mathematical model was then used to investigate the effect of radial angle between oxygen lance nozzles and bottom blowing tuyeres on Molten Bath flow properties, which revealed the fluid flow mechanism in combined blown converter. Based on the Molten Bath flow field, mathematical model describing the erosion behavior of converter lining was established and erosion characteristics in combined blown converter was researched. The results showed that radial angle between oxygen lance nozzles and bottom blowing tuyeres has an important influence on converter Bath velocity field distribution and lining erosion.

  • Effect of oxygen flow rate and temperature on supersonic jet characteristics and fluid flow in an EAF Molten Bath
    Canadian Metallurgical Quarterly, 2017
    Co-Authors: Shaoyan Hu, Kai Dong
    Abstract:

    ABSTRACTA new operation method for the oxygen lance of an electric arc furnace (EAF) was proposed, meeting the simultaneous demand for low oxygen flow rate and high stirring power in a particular smelting stage. When the oxygen flow rate needs to be reduced, the stirring power of the jet can be improved by increasing oxygen temperature properly. Free supersonic jet characteristics at different flow rates and stagnation temperatures were studied by numerical simulation and validated by a jet measurement experiment. The results showed that the designed Mach number can be maintained by coupling adjustment of flow rate and stagnation temperature. Meanwhile, a three-phase, full-scaled numerical model for a commercial 75t EAF with three oxygen lances on the side-wall was established to study the fluid flow in the Molten Bath. The velocity distribution, cavity profile and total kinetic energy of the EAF Bath induced by the impingement of supersonic jets onto the liquid Bath were discussed and compared. It was fo...

Tooru Tsuru - One of the best experts on this subject based on the ideXlab platform.

  • electrodeposition of al ni intermetallic compounds from aluminum chloride n n butyl pyridinium chloride room temperature Molten salt
    Journal of Electroanalytical Chemistry, 2001
    Co-Authors: A Nishikata, Tooru Tsuru
    Abstract:

    Abstract Electrodeposition of aluminum–nickel intermetallic compounds (particularly Ni 3 Al) has been carried out onto platinum and mild steel cathodes from a 2:1 (mole ratio) aluminum(III) chloride- N -( n -butyl)pyridinium chloride (BPC) Molten Bath saturated with nickel(II) chloride at room temperature. A single phase of Al–Ni alloy is difficult to obtain by controlled-potential and controlled-current methods; however, it can be obtained by pulse current plating. The electrodeposition of nickel from an AlCl 3 –BPC–NiCl 2 (6.14:3.07:0.09 mole ratio) Molten Bath occurs via an instantaneous nucleation mechanism in the very initial stage of the crystal growth. The deposition reaction mechanisms of nickel in this Molten Bath are revealed by electrochemical analysis. The experimental Tafel slope of 42 mV dec −1 and the calculated transfer coefficient α → c of 1.5 suggest that the rate determining step is a charge transfer reaction of an adsorbed bare monovalent cation to the metallic state. The effect of the cycle regime on the electrodeposition of Al–Ni alloys has been investigated. The current efficiency for the deposition of alloys is about 99%.

  • Electrodeposition mechanism of aluminium from aluminium chloride-N-(n-butyl)pyridinium chloride room temperature Molten salt
    Indian Journal of Chemical Technology, 1999
    Co-Authors: A Nishikata, Tooru Tsuru
    Abstract:

    ,Electrodeposition of aluminium has been carried out by controlled-current and controlled-potential methods from acidic aluminum(lII) chloride-N-(n-butyl)pyridinium chloride (BPC) Molten Bath at room temperatUre. The electrodeposition of alumini um from acidic AlClrBPC melt occurs via instantaneous nucleation mechanism in the very initial stage of the crystal growth. The deposition reaction mechanisms of al uminium in the acidic AlCh-BPC Molten Bath are revealed by electrochemical analysis. The experimental Tafel slo6e of 20 mY dec- I and the calculated transfer coefficient (ue) of 3 suggest that th e rate determining step is a chemical re ac tion involving the release of the compl exi ng agents vi a three consecutive single electron transfer steps. The influence of various conditions on electrodeposition and the morphology of the electrodeposited layers have been in vestigated by X-ray di'ffractometry and scanni ng electron microscopy. On increasing the current density smaller particle size and better adhesiveness of the electrodeposited layers have been obtained. The cathodic current efficiency for the depositi on of Aluminium is about 99.8%.

A Nishikata - One of the best experts on this subject based on the ideXlab platform.

  • electrodeposition of al ni intermetallic compounds from aluminum chloride n n butyl pyridinium chloride room temperature Molten salt
    Journal of Electroanalytical Chemistry, 2001
    Co-Authors: A Nishikata, Tooru Tsuru
    Abstract:

    Abstract Electrodeposition of aluminum–nickel intermetallic compounds (particularly Ni 3 Al) has been carried out onto platinum and mild steel cathodes from a 2:1 (mole ratio) aluminum(III) chloride- N -( n -butyl)pyridinium chloride (BPC) Molten Bath saturated with nickel(II) chloride at room temperature. A single phase of Al–Ni alloy is difficult to obtain by controlled-potential and controlled-current methods; however, it can be obtained by pulse current plating. The electrodeposition of nickel from an AlCl 3 –BPC–NiCl 2 (6.14:3.07:0.09 mole ratio) Molten Bath occurs via an instantaneous nucleation mechanism in the very initial stage of the crystal growth. The deposition reaction mechanisms of nickel in this Molten Bath are revealed by electrochemical analysis. The experimental Tafel slope of 42 mV dec −1 and the calculated transfer coefficient α → c of 1.5 suggest that the rate determining step is a charge transfer reaction of an adsorbed bare monovalent cation to the metallic state. The effect of the cycle regime on the electrodeposition of Al–Ni alloys has been investigated. The current efficiency for the deposition of alloys is about 99%.

  • Electrodeposition mechanism of aluminium from aluminium chloride-N-(n-butyl)pyridinium chloride room temperature Molten salt
    Indian Journal of Chemical Technology, 1999
    Co-Authors: A Nishikata, Tooru Tsuru
    Abstract:

    ,Electrodeposition of aluminium has been carried out by controlled-current and controlled-potential methods from acidic aluminum(lII) chloride-N-(n-butyl)pyridinium chloride (BPC) Molten Bath at room temperatUre. The electrodeposition of alumini um from acidic AlClrBPC melt occurs via instantaneous nucleation mechanism in the very initial stage of the crystal growth. The deposition reaction mechanisms of al uminium in the acidic AlCh-BPC Molten Bath are revealed by electrochemical analysis. The experimental Tafel slo6e of 20 mY dec- I and the calculated transfer coefficient (ue) of 3 suggest that th e rate determining step is a chemical re ac tion involving the release of the compl exi ng agents vi a three consecutive single electron transfer steps. The influence of various conditions on electrodeposition and the morphology of the electrodeposited layers have been in vestigated by X-ray di'ffractometry and scanni ng electron microscopy. On increasing the current density smaller particle size and better adhesiveness of the electrodeposited layers have been obtained. The cathodic current efficiency for the depositi on of Aluminium is about 99.8%.

Mingming Li - One of the best experts on this subject based on the ideXlab platform.

  • transferring characteristics of momentum energy during oxygen jetting into the Molten Bath in bofs a computational exploration
    Steel Research International, 2016
    Co-Authors: Mingming Li, Qiang Li, Shibo Kuang
    Abstract:

    Mingming Li, Qiang Li, Shibo Kuang, and Zongshu ZouThis paper presents a numerical study of transferring characteristics of momentum/energyduring oxygen jetting into the slag–metal Molten Bath in basic oxygen furnaces by a multi-fluid volume of fluid model. The evolution of the momentum/energy and turbulence of jetsalong their axial travel were studied. The results were quantitatively compared within awide range of oxygen supply pressures, at which the jets may be at under- or over-expanding state. The efficiency of the momentum/energy transfer from the jets to theMolten Bath was also assessed with respect to lance height and operation pressure. Thenumerical results show that the momentum and kinetic energy for the jets suffering fromshock waves likely cause more intensive damping compared to the jets with expansionwaves. The turbulence kinetic energy and turbulence dissipation rate are observed to firstlyincrease and then decrease. This effect is more pronounced at a lower operation pressure.Based on these results, the optimum lance height was identified for a rapid slaggingoperation. It is also shown that the efficiency of the energy transfer from the jets to theMolten Bath is very low. Decreasing lance height or increasing operation pressurepromotes the efficiency of the momentum transfer from the jets to the Molten Bath butlowers the efficiency of the kinetic energy transfer.

  • Transferring Characteristics of Momentum/Energy during Oxygen Jetting into the Molten Bath in BOFs: A Computational Exploration
    Steel Research International, 2015
    Co-Authors: Mingming Li, Qiang Li, Shibo Kuang
    Abstract:

    Mingming Li, Qiang Li, Shibo Kuang, and Zongshu ZouThis paper presents a numerical study of transferring characteristics of momentum/energyduring oxygen jetting into the slag–metal Molten Bath in basic oxygen furnaces by a multi-fluid volume of fluid model. The evolution of the momentum/energy and turbulence of jetsalong their axial travel were studied. The results were quantitatively compared within awide range of oxygen supply pressures, at which the jets may be at under- or over-expanding state. The efficiency of the momentum/energy transfer from the jets to theMolten Bath was also assessed with respect to lance height and operation pressure. Thenumerical results show that the momentum and kinetic energy for the jets suffering fromshock waves likely cause more intensive damping compared to the jets with expansionwaves. The turbulence kinetic energy and turbulence dissipation rate are observed to firstlyincrease and then decrease. This effect is more pronounced at a lower operation pressure.Based on these results, the optimum lance height was identified for a rapid slaggingoperation. It is also shown that the efficiency of the energy transfer from the jets to theMolten Bath is very low. Decreasing lance height or increasing operation pressurepromotes the efficiency of the momentum transfer from the jets to the Molten Bath butlowers the efficiency of the kinetic energy transfer.

  • numerical simulation of the interaction between supersonic oxygen jets and Molten slag metal Bath in steelmaking bof process
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2015
    Co-Authors: Qiang Li, Mingming Li, Shibo Kuang
    Abstract:

    The impinging of multiple jets onto the Molten Bath in the BOF steelmaking process plays a crucial role in reactor performance but is not clearly understood. This paper presents a numerical study of the interaction between the multiple jets and slag–metal Bath in a BOF by means of the three-phase volume of fluid model. The validity of the model is first examined by comparing the numerical results with experimental measurement of time-averaged cavity dimensions through a scaled-down water model. The calculated results are in reasonably good agreement with the experimental data. The mathematical model is then used to investigate the primary transport phenomena of the jets-Bath interaction inside a 150-ton commercial BOF under steelmaking conditions. The numerical results show that the cavity profile and interface of slag/metal/gas remain unstable as a result of the propagation of surface waves, which, likely as a major factor, governs the generation of metal droplets and their initial spatiotemporal distribution. The total momentum transferred from the jets into the Bath is consumed about a half to drive the movement of slag, rather than fully converted as the stirring power for the metal Bath. Finally, the effects of operational conditions and fluid properties are quantified. It is shown that compared to viscosity and surface tension of the melts, operating pressure and lance height have a much more significant impact on the slag–metal interface behavior and cavity shape as well as the fluid dynamics in the Molten Bath.

  • PRICM: 8 Pacific Rim International Congress on Advanced Materials and Processing - Numerical Study on Behavior of Top-Blown Supersonic Jets and Their Interaction with Bath in BOF Steelmaking Convertor
    Proceedings of the 8th Pacific Rim International Congress on Advanced Materials and Processing, 2013
    Co-Authors: Mingming Li, Qiang Li, Lin Li, Mingxia Feng, Zuoliang Zhang
    Abstract:

    A three-dimensional transient CFD model combined VOF interface tracking technique for compressible supersonic oxygen-jets impinging on the free surface of Molten slag/metal is developed. Jets behavior at steelmaking temperature is investigated, and simulation results are validated by comparison with experiments. Interaction of jets and Molten Bath, impinged deformation of slag/metal interface and its evolution with time are discussed. The results show that penetration depth increases with the decrease of lance height and with the increase of operation pressure. Impact area shrinks with the drop of lance height, but is almost unaffected by operation pressure. The shape of depression and interface of slag/steel/gas is found to be instable and oscillatory with time due to propagation of waves in cavities. The circulation of Molten Bath is formed, and the position of vortex changes with blowing time and interface movement.

Shibo Kuang - One of the best experts on this subject based on the ideXlab platform.

  • transferring characteristics of momentum energy during oxygen jetting into the Molten Bath in bofs a computational exploration
    Steel Research International, 2016
    Co-Authors: Mingming Li, Qiang Li, Shibo Kuang
    Abstract:

    Mingming Li, Qiang Li, Shibo Kuang, and Zongshu ZouThis paper presents a numerical study of transferring characteristics of momentum/energyduring oxygen jetting into the slag–metal Molten Bath in basic oxygen furnaces by a multi-fluid volume of fluid model. The evolution of the momentum/energy and turbulence of jetsalong their axial travel were studied. The results were quantitatively compared within awide range of oxygen supply pressures, at which the jets may be at under- or over-expanding state. The efficiency of the momentum/energy transfer from the jets to theMolten Bath was also assessed with respect to lance height and operation pressure. Thenumerical results show that the momentum and kinetic energy for the jets suffering fromshock waves likely cause more intensive damping compared to the jets with expansionwaves. The turbulence kinetic energy and turbulence dissipation rate are observed to firstlyincrease and then decrease. This effect is more pronounced at a lower operation pressure.Based on these results, the optimum lance height was identified for a rapid slaggingoperation. It is also shown that the efficiency of the energy transfer from the jets to theMolten Bath is very low. Decreasing lance height or increasing operation pressurepromotes the efficiency of the momentum transfer from the jets to the Molten Bath butlowers the efficiency of the kinetic energy transfer.

  • Transferring Characteristics of Momentum/Energy during Oxygen Jetting into the Molten Bath in BOFs: A Computational Exploration
    Steel Research International, 2015
    Co-Authors: Mingming Li, Qiang Li, Shibo Kuang
    Abstract:

    Mingming Li, Qiang Li, Shibo Kuang, and Zongshu ZouThis paper presents a numerical study of transferring characteristics of momentum/energyduring oxygen jetting into the slag–metal Molten Bath in basic oxygen furnaces by a multi-fluid volume of fluid model. The evolution of the momentum/energy and turbulence of jetsalong their axial travel were studied. The results were quantitatively compared within awide range of oxygen supply pressures, at which the jets may be at under- or over-expanding state. The efficiency of the momentum/energy transfer from the jets to theMolten Bath was also assessed with respect to lance height and operation pressure. Thenumerical results show that the momentum and kinetic energy for the jets suffering fromshock waves likely cause more intensive damping compared to the jets with expansionwaves. The turbulence kinetic energy and turbulence dissipation rate are observed to firstlyincrease and then decrease. This effect is more pronounced at a lower operation pressure.Based on these results, the optimum lance height was identified for a rapid slaggingoperation. It is also shown that the efficiency of the energy transfer from the jets to theMolten Bath is very low. Decreasing lance height or increasing operation pressurepromotes the efficiency of the momentum transfer from the jets to the Molten Bath butlowers the efficiency of the kinetic energy transfer.

  • numerical simulation of the interaction between supersonic oxygen jets and Molten slag metal Bath in steelmaking bof process
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2015
    Co-Authors: Qiang Li, Mingming Li, Shibo Kuang
    Abstract:

    The impinging of multiple jets onto the Molten Bath in the BOF steelmaking process plays a crucial role in reactor performance but is not clearly understood. This paper presents a numerical study of the interaction between the multiple jets and slag–metal Bath in a BOF by means of the three-phase volume of fluid model. The validity of the model is first examined by comparing the numerical results with experimental measurement of time-averaged cavity dimensions through a scaled-down water model. The calculated results are in reasonably good agreement with the experimental data. The mathematical model is then used to investigate the primary transport phenomena of the jets-Bath interaction inside a 150-ton commercial BOF under steelmaking conditions. The numerical results show that the cavity profile and interface of slag/metal/gas remain unstable as a result of the propagation of surface waves, which, likely as a major factor, governs the generation of metal droplets and their initial spatiotemporal distribution. The total momentum transferred from the jets into the Bath is consumed about a half to drive the movement of slag, rather than fully converted as the stirring power for the metal Bath. Finally, the effects of operational conditions and fluid properties are quantified. It is shown that compared to viscosity and surface tension of the melts, operating pressure and lance height have a much more significant impact on the slag–metal interface behavior and cavity shape as well as the fluid dynamics in the Molten Bath.