FLUID TO PARTICLE HEAT-TRANSFER IN A FLUIDIZED-BED AND TO SINGLE PARTICLES

A frequency response technique to evaluate gas to particle heat transfer coefficients to solid spheres and to fine particle fluidized beds is described. At low Reynolds numbers, the single particle Nusselt number approaches 2 as expected. However, the general magnitude for fine particle fluidized beds is 20-100 times those for packed or single particle systems, in marked contrast to the literature data. The present results are more rational, but still are model dependent as are all the other fluidized bed results.