Maximum Heat Transfer Coefficient between a Horizontal Tube and a Gas-Solid Fluidized Bed

Abstract

Experiments have been conducted to measure the maximum heat transfer coefficient, hh,max, between an electrically heated single horizontal tube and air-solid square fluidized beds of glass beads, dolomie, sand, silicon carbide, and alumina particles. The effect of particle size, shape, density, and specific heat, tube size, bed depth, heat flux, and distributor design on maximum heat transfer rate has been investigated. Experimental values of hh,max are compared with the values of maximum heat transfer coefficient predicted by the existing correlations. None of these correlations is found to be adequate to reproduce the present data. Therefore a new correlation has been proposed for hh,max on the basis of our data and then examined to assess its reliability on the basis of available data in the literature. In addition, the existing correlations for bed porosity, ∈, and optimum mass fluidizing velocity, Gopt, have been examined on the basis of our data and a new correlation is given for the bed porosity. © 1981, American Chemical Society. All rights reserved.