“Generalized Fluidization” Revisited

Abstract

The generalized fluidization diagram was drawn by Kwauk [Scientia Sinica, 1963, 12 (4), 587–612] and Kwauk [Science Press, Beijing: 1992] for fluidization under steady-state motion. In this article, we try to extend the work of Kwauk and redraw the diagram by taking into account the effects of mesoscale structures on drag force closure. The generalized choking is then defined on the new diagram, which is characterized by the bistable, coexisting states in both concurrent and countercurrent flows. The theoretical predictions are tested against experimental data, showing fair agreement especially for countercurrent gas-up flows and concurrent-down flows.