Correlation for Calculating Heat Transfer Coefficient in Conical Spouted Beds

Abstract

A correlation has been proposed for predicting local bed-to-surface heat transfer coefficients in conical spouted beds based on an experimental study conducted using beds made up of sand, sawdust, and their mixtures under various operating conditions, namely, different static bed heights and gas velocities over minimum spouting. A comparison of the results with those obtained using the correlations in the literature proved that they provide very poor predictions and, furthermore, they are not able to predict local coefficients in the bed. Based on a statistical analysis, the significant moduli have been identified in the relevant literature correlations and two new moduli related to the radial and longitudinal positions have been contemplated. The analysis identified two groups of heat transfer coefficients: those within the bed and those on its surface. The correlation proposed is specifically suitable for ascertaining the best location of heat transfer devices within the annulus of the spouted beds.