| There is a lot of heat loss of molten steel in the tundish.The heat loss can be made up by the induction heating.What's more,the removal ratio of inclusions in the tundish was also improved,tundish with induction heating has been identified as a generic technology for continuous casting process.A three-dimensional transient mathematical modeling has been developed to investigate the electromagnetic phenomena,fluid flow and temperature field in the continuous casting tundish with sidewall-type induction heating.Eight kinds of electromagnetic fields in the tundish with different induction heaters are studied,the magnetic field,induced current,electromagnetic force and Joule heating distribution in the tundish with different induction heating power are studied by finite element method.Based on the finite volume method,the fluid flow and heat transfer behavior of the molten steel with the magnetic field were coupled and solved,then the optimal induction heating method and the parameters of the heating power meeting the target temperature range were obtained.Finally,the residence time distribution(RTD)curve was obtained by monitoring the tracer concentration of each nozzle,then the average residence time of the molten steel in the tundish and volume ratio of dead zone were studied.The induced current was nonuniform distribution in the tundish with sidewall-type induction heating and the induced current was larger near the heating side.The electromagnetic force generated due to the interaction of magnetic field with induced current is pointing to the tundish.The molten steel with the electromagnetic force went forward while it kept rotational motion.The flow paths of the molten steel were prolonged,average residence time and the flow properties of the molten steel were improved.With the same induction heating power,the electromagnetic field region and improvement of fluid flow,temperature distribution and RTD curve with heating mode of the bipolar core electromagnetic induction heater was greater than with heating mode of the tri-polar core electromagnetic induction heater.The electromagnetic field action region in the tundish increased and magnetic flux density,induced current,electromagnetic force and joule heating decreased,when the electromagnetic induction heaters were symmetrical arranged.The heat efficiency and the tundish metallurgical effect of the heating mode with unilateral heater was better than of the heating mode with bilateral symmetrical arrangement heater.The electromagnetic field with sidewall-type induction heating was mainly in the tundish pouring area;Improving fluid flow and temperature distribution of the molten steel in the pouring area or the pouring region of tundish is the key.Fluid flow and temperature distribution of the molten steel in the tundish were improved by moving electromagnetic induction heater towards the end of the tundish pouring area.Heat efficiency with the channel-type induction heating was 80%-90%,according to the results of industrial test and the online operation.With sidewall-type induction heating,the temperature of the molten steel in the 35t tundish with induction heating power of 500-1000kW was controlled in the range of ±2.5 ?,heat efficiency was 88%.So the tundish with sidewall-type induction heating can be a new indtuction heating technology of tundish. |
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