THE EXPANSION OF GAS-FLUIDIZED BEDS IN BUBBLING FLUIDIZATION

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.