Experimental study of the effects of thermal and solutal convections in the continuous cast of a binary mixture
Article
DeZego, SE, Jones, WK, Dong, ZF et al. (1996). Experimental study of the effects of thermal and solutal convections in the continuous cast of a binary mixture
. American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD, 333 331-341.
DeZego, SE, Jones, WK, Dong, ZF et al. (1996). Experimental study of the effects of thermal and solutal convections in the continuous cast of a binary mixture
. American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD, 333 331-341.
An experimental study of the solidification process for the continuous cast of a binary NH4Cl-H2O solution with varying inlet temperature and compositon has been performed. Thermal and solutal density gradients have been found to strongly affect flow in the liquid region and are mainly responsible for the redistribution of species on the macroscopic scale. Flow visualizations have shown that dense solute-rich solution, rejected from the mushy zone, was redistributed into the upper regions of the liquid melt during cases of hypoeutectic initial concentrations. Localized remelting and shearing of columnar dendritic growth for the hypoeutectic cases and the redistribution and melting of equiaxed dendritic growth for the hypereutectic cases have also been found to strongly depend on the solution inlet temperature. It was established that the extent of equiaxed free solid that accumulated in the lower region of the liquid melt for the hypereutectic cases was dependent on the initial solution composition. Concentration histories show that segregation of species along the vertical centerline in the liquid pool have been measured to be in excess of 4% for some cases during quasisteady conditions. The warm buoyant solution entering the liquid melt via the feeding nozzle significantly increased convective effects that were not detected in previous research on static test sumps.
