Analysis of the void fraction around a surface immersed in a fluidized bed by surface-to-bed heat transfer measurements

A semi-empirical model is used to calculate the averaged surface void fraction in fluidized beds, εw, starting from experimental data on surface-to-bed heat transfer coefficient. The model is able to describe the effect of the main process parameters and shows that εw increases with minimum fluidization void fraction and particle Archimedes number.