We have conducted laboratory experiments of solidification on a cooling vertical cylinder in a hypoeutectic sodium nitrate solution that fills rectangular vessel, and formulated one-dimensional model for predicting the vertically averaged solid layer thickness. The experiments have been carried out by heating the lower wall of the vessel and cooling the vertical cylinder. Stratified concentration layers are formed in the vessel with the growth of solid due to the solute emission. As the process advances, the solution is eventually divided into two layers with a large density difference. The two layers have different average temperatures and concentrations. Taking the presence of the two layers into consideration, we have formulated the one-dimensional model for the growth of solid layer. The theoretical predictions compares well with the experimental results.
