A generalized bubble diameter correlation for gas‐solid fluidized beds

Abstract

Abstract A new bubble diameter correlation is derived to predict bubbling characteristics of fluidized beds of varieties of powders. The present model is founded on the postulate that the steady bubble size, which is often called the maximum stable diameter, observed in a bed of Geldart group A powder is formed as a result of an equilibrium of successive coalescence and splitting. For the cases of group B powders the present correlation automatically converges to the conventional correlation of Mori and Wen (1975), whose predictions are close to those of Rowe (1976) and Darton et al. (1977). For group A powders the present correlation is validated by comparison with experimental data in the literature. Based on this correlation a theoretical explanation is presented for the fact that the maximum bubble diameters observed were up to 50 to 100 times as large as those from the stable bubble theory of Harrison et al. (1961).