Influence of vibration characteristics on temperature uniformity of particles during heating processes in a vibrationally fluidized bed

Abstract

Granular heat transfer is encountered in many industries, including food production, solar energy harvesting and nuclear engineering. The present study investigates influence of vibration characteristics on granular heat transfer in a vibrationally fluidized bed of particles using a thermal discrete element method. The bed is heated by transferring a constant heat flux from its bottom wall. Vibrations generally had two influences: first, particles reached a higher average temperature, and second, they attained more uniform temperature distribution. The particles average temperature generally increased by increasing vibration amplitude and frequency. However, the best temperature uniformity occurred in an optimal set of amplitudes and frequencies. Contrary to claims in previous studies, the effective thermal conductivity (ETC) of the vibrated bed was not the only determining parameter for quality of heat transfer. Other parameters such as flow patterns, convective and diffusive motions must be also analyzed to evaluate the heating process in vibrating beds.