Further study on the influence of particle coating on fluidized bed heat transfer

Heat transfer to an immersed sphere from fluidized uncoated sand particles of different mean size and size distribution is compared with that from coated sand particles of equal size extracted from two full-scale fluidized bed boilers for different superficial gas velocities and mean particle diameters from 350 to 646 μm. The thin coating on the sand bed particles from full-scale boilers was found to have a significant effect on the heat transfer coefficient, while the particle size distributions, as well as coating thickness, had little or no influence on the heat transfer coefficients for the conditions investigated.