Particle-to-gas heat transfer coefficients were determined in packed and fluidized beds with large diameter particles and high mass velocities using the cyclic temperature method.

Experimental results for packed beds were satisfactorily correlated within 10% deviation as εjh vs. NRe and were found to compare favorably with results of other experimenters obtained with much lower mass velocities and larger particles. The particle-to-gas heat transfer coefficient varied as G0.60 for the steel spheres vs. G0.66 for the tungsten spheres, and as Dp−0.44.

Heat transfer coefficients obtained at minimum fluidization were in good agreement with those obtained with packed beds. As the mass velocity was increased above that required for minimum fluidization, heat transfer coefficients remained essentially constant.