An experimental study to evaluate the convective heat transfer coefficient in
a cylindrical packed bed of spherical porous alumina particles is
investigated. The task consists in proposing a semi-empirical model to avoid
excessive instrumentation and time consumption. The measurement of the bed
temperature associated to a simple energy balances led to calculate the gas
to particle heat transfer coefficient using a logarithmic mean temperature
difference method. These experiments were performed at atmospheric pressure.
The operating fluid is humid air. The gas velocity and temperature ranged
from 1.7-3 m/s and 120-158?C, respectively. The data obtained was compared
with the correlations reported in the literature. It is shown that the
proposed model is in reasonable agreement with the correlation of Ranz and
Marshall. Despite, many researches on experimental investigations of heat
transfer coefficient in packed beds at low and average temperature are
proposed, few studies presented calculation of convective heat transfer
coefficient at high temperature (above 120?C). A possible application of the
proposed model is drying and combustion.
Convective Heat Transfer Coefficient in a Packed Bed of Rice
