Enhancement of large-particle gas-fluidization by adding liquid

There are circumstances where fluidization of particles by a gas can be promoted by the addition of small quantities of liquid, contrary to many reported cases where liquid impedes gas-solid fluidization. Enhancement occurs only when the particles are larger than about 3 mm in diameter, the liquid and particles have similar densities (within ∼25%), and the particles are poorly wetted by the liquid. When these conditions are met, the liquid causes the minimum gas fluidization velocity U_gmf to decrease and particle motion to be more vigorous. For low liquid loadings, U_gmf and the pressure drop across the bed are then predicted well by a "modified liquid-perturbed gas model.".