A model for predicting the performance of a batch fountain confined spouted bed dryer at low and moderate temperatures

Abstract

Spouted bed dryers are well known for their high efficiency at low and moderate temperatures. The design of industrial scale dryers requires the estimation of heat and mass transfer coefficients, but there is hardly any information involving their estimation in fountain confined conical spouted beds. Thus, a model is proposed for predicting their performance, which is based on unsteady state heat and mass balances for the solid and air phases in the spout, fountain and annulus. It was validated by comparing the output values with those obtained in previous batch drying runs, and therefore allows predicting the dryer performance and the mass transfer coefficient. The results show that the temperature and velocity of the air at the inlet, as well as the solid properties, are highly influential parameters, which is explained by the level of turbulence attained. Therefore, this model allows predicting the performance of industrial spouted bed dryers.