Numerical Simulation of Fluid Flow and Heat Transfer in a Ductile Iron Ladle During Holding and Teeming

A 3D transient numerical model of a ductile iron ladle has been developed to predict the fluid flow and temperature drop during the holding and teeming. The volume of fluid (VOF) multiphase model has been employed to track the interface between the liquid metal and the air. The SST k-ω model has been applied to model the turbulence due to natural convection in the ladle. The temperature evaluation in the refractory lining walls during preheating and teeming is shown. Appropriate boundary conditions are applied for natural convection and radiation to surroundings from all the outer steel surfaces as well as from the top glass wool cover. The heat loss due to radiation from the liquid metal surface to the surrounding walls is also considered in the present model by applying an energy sink term to the cells at the interface. The numerical results of the 780 kg ladle have been compared with the measured temperature drop of the metal using an S-type thermocouple for two ladle cycles and the difference between the measured and predicted temperature at the end of two cycles is 3 °C. Decreasing the ladle capacity to 650 kg for pouring the same amount of metal increased the temperature drop by 11 °C due to increase in surface area to melt volume ratio. Also increasing the refractory thickness for 650 kg ladle increased the temperature drop by 4 °C due to the heat accumulation in the ladle during the cyclic transient heat transfer process.