The ratio of terminal velocity to minimum fluidising velocity for spherical particles

Abstract

Abstract The analogy between the states of a particle falling at its terminal velocity in a fluid and that of a particle in a bed, at incipient fluidization by the same fluid, suggests the possibility of a correlating minimum fluidizing and terminal velocities and of predicting the minimum fluidizing velocity. A semi‐theoretical curve has been obtained, relating ( Re t / Re mf ) to Fn = gp F (rH S – rH F ) d 3 /μ 2 and it has been compared with new experimental data collected for this purpose in the range 10 3 < Fn <10 8 . Analytical expressions for ( Re t / Re mf ) are proposed.