Publication: ESTIMATION OF ENERGY CONSUMPTION IN THERMAL STERILIZATION OF CANNED LIQUID FOODS IN STILL RETORTS
Abstract
Thermal sterilization of canned liquid foods using saturated steam is dominated by natural convective heat transfer. The temperature in the can is strongly influenced by the velocity patterns and varies both with position and time thereby making estimations of heat transfer rates and energy consumption difficult. Computational Fluid Dynamics (CFD) simulations are carried out to determine the temperature-time history in cans of different aspect ratios and food media thermal conductivities. Correlations are developed for the variation of the volume averaged temperature and heat transfer flux with time during different phases of the heating period. Integrating the heat transfer expressions over the entire duration of the heating period, closed form solutions of energy consumption are developed. These expressions for heat transfer rate and energy consumption may be incorporated into various process design, operation and optimization strategies in batch still retort operations.