AbstractThermal phenomena are associated with the operation of ice counter‐washers, a major component for the separation of ice and brine in freeze crystallization processes. Melting, freezing, and channeling in the upper leg of the counterwasher occur because of the temperature difference between the wash water and the ice and have important effects on the operation of the device. In the present study, these phenomena are modeled and analyzed and their scaling laws derived. Ice and wash water temperature distributions as well as variations in porosity and wash water flow rate due to melting and freezing in the ice plug are computed and plotted. The effect of channeling on counterwasher operation is studied and formulated in terms of the channel dimensions and ice plug properties. Growth rates of channels due to melting by the wash water are calculated. Results indicate that warm wash water and slow motion of the ice plug cause rapid channel growth and may be deleterious to counterwasher operation. Best conditions for recovery from channeling are obtained with wash water temperature close to freezing and high plug velocity.