The expansion of gas-fluidised beds has been examined in the range of
Archimedes number from 100 to 10(5) using five grades of glass balloti
ni and two grades of lead shot of narrow size distribution, and Diakon
particles of wide size distribution. A porous plastic distributor pla
te was used in beds of diameters 89 and 290 mm. Power law and exponent
ial correlations of the expansion were examined. All of the experiment
al data were correlated within experimental error by the equation rho(
b)/rho(mf) = exp[-0.0052U(U/U-mf - 1)]. The dimensionless group U*, n
ot apparently considered elsewhere, is defined as U-t(rho/mu g)(1/3) w
here U-t is the particle terminal velocity. (C) 1997 Elsevier Science
Ltd.