Research On Electromagnetic Field And Inclusion Removal In Electromagnetic Induction Heating Channel

Channel-type electromagnetic induction heating tundish is a tundish secondary refining technology developed with the continuous development of continuous casting technology,which can effectively improve continuous casting productivity,improve the quality of slab,and promote energy conservation and emission reduction.As the technology is still in a preliminary stage of development in China,the current research focuses on the numerical simulation of the temperature field and flow field of molten steel in the tundish,and there are few studies on the magnetic flux density,induced current intensity,electromagnetic force,Joule heat and other physical quantity distribution in the channel.The ANSYS finite element electromagnetic field analysis was used to numerically calculate the magnetic induction intensity in the induction heating channel,the induced current intensity in molten steel,the electromagnetic force received by molten steel,and the distribution of Joule heat in liquid steel under different current intensity and frequency conditions.Through physical simulation experiments,the removal of inclusions under different inductive heating currents and fluids in the channel at different flow rates was also studied.The main conclusions are as follows:?1?The magnetic induction intensity in the channel is symmetrically distributed along the center of the channel.In the axial direction of the channel,the distribution of magnetic induction intensity is not uniform.The magnetic induction intensity is larger in the middle of the channel,and the maximum and minimum values appear near the end of the channel.The magnetic induction intensity in the diameter direction of the channel has the same distribution rule,and its magnitude remains the same and similar.The induced current density,electromagnetic force,and Joule heat are symmetrically distributed in the direction of the channel axis with respect to the center section of the channel,and the maximum value appears in the middle of the channel,and a minimum occurs near the end of the channel.The induced current density,electromagnetic force,and Joule heat in the radial section of the channel are distributed unevenly and gradually decrease from the channel surface toward the center of the channel.?2?The magnetic induction intensity in the channel and the current density produced by the molten steel increase linearly with the increase of the coil current intensity.When the coil applies a current frequency of 45 kHz and the intensity is in the range of 15 to 45 A,the current increases by 10 A.The magnetic induction intensity in the straight direction of X=9.0 mm in the channel will increase by about1.0⁴×10^-3 T,and the current density in the channel Z=10 mm will increase by about1.1×10⁶ A·m^-2.The electromagnetic force exerted on the molten steel and the Joule heat generated will also increase with the coil current intensity.When the current intensity increases from 15 A to 45 A,the electromagnetic force on the channel surface is 164.04 N·m^-3.Increased to 1448 N·m^-3,Joule heat increased from 1.51×10⁵W/m² to 1.37×10⁶ W/m².?3?The magnetic induction and electromagnetic force in the channel decrease with the increase of the current frequency.The induced current density on the channel surface and the Joule heat generated by the molten steel increase with the increase of the current frequency.When the current intensity is 45 A,when the current frequency increases from 20 kHz to 50 kHz,the maximum magnetic induction intensity on the channel surface decreases from 1.42×10^-2 T to 3.58×10^-3 T.The maximum value of the electromagnetic force is 4779.37 N·m^-3 decreased to 949.07 N·m^-3.The maximum current density generated by molten steel on the channel surface increased from2.26×10⁶ A·m^-2 to 2.60×10⁶ A·m^-2,and the Joule heat generated by the molten steel increased from 1155387.75 W/m² to 1394775.75 W/m².?4?Under the condition that the channel solution flow rate is 4 ml/s¹6 ml/s,the adsorption rate of the iron powder on the channel wall surface gradually increases as the current in the coil increases from 15 A to 45 A,but the increment increases.Smaller.When the channel solution flow rate was 4 ml/s,8 ml/s,and 16 ml/s,the adsorption rate of iron powder on the channel wall surface increased from 92%to96%,and 88%to 95%,72,respectively.%increase to 91%;at the channel solution flow rate of 24 ml/s and 34 ml/s,as the current increases from 15 A to 45 A,the adsorption rate of the iron powder on the channel wall gradually increases,and its increment increases.When the flow rate of the channel solution was 24 ml/s and 34ml/s,the adsorption rate of the iron powder on the channel wall increased from 60%to 84%and 10%to 78%,respectively,with the increase of current.?5?The velocity and current size of the molten steel in the channel have an effect on the removal of inclusions in the steel.When the current applied in the coil is small,the flow rate of the solution in the channel has a greater influence on the amount of the adsorbed inclusions on the channel wall;when the coil is applied When the current is large,the effect of the flow rate of the solution in the channel on the amount of inclusions adsorbed on the wall of the channel is reduced,and increasing the current applied in the coil can significantly increase the adsorption rate of inclusions on the wall surface of the channel at high flow rates of the channel solution.