Solidification of aqueous ammonium chloride in a rectangular cell under constant wall temperature - an experimental study

The effect of a binary alloy solidification process was investigated for four different initial ammonium chloride concentrations (5%, 10%, 15% and 25%) and for four different constant wall temperature conditions (−13°C, −20°C, −25°C and −30°C). The solidification process inside the test cell was interrupted at various time steps to capture the phase front profile. Results show that a higher initial concentration and a lower constant wall temperature tend to increase the strength of thermal-driven buoyancy flow and solute-driven buoyancy flow respectively. The shape of both the solid and mushy phase front profiles are affected by the strength of these two flows. Isotherm plots and superimposed images are used to determine the location of solid-must interface and must-liquid interface respectively, inside the test cell at any time interval.