Hydrodynamic studies on zeolite fluidized beds

The present study presents systematic experimental data on the fluidization of zeolite particles in water-solid fluidized beds. Four particle size groups, 90-180 μm, 180-250 μm, 250-315 μm and 315-500 μm and 22 different volumetric flow rates were used, corresponding to Rep of 0.012 to 1.452. All particle sizes showed smooth flow rate vs expanded bed height curves. As is proven, the Ergun equation is useful for determining the minimum fluidization velocity for the large particle sizes by using a fixed sphericity value of 0.354. For the fluidized bed regime (us>umf), the Ergun equation fails to represent the data as it results in fluctuating particle sphericity values, while the Richardson-Zaki model seems to correlate the data for the large particle sizes only. A new correlation is presented, connecting bed voidage to Rep for all particle sizes with an average relative error of 2.38±2.49% and the range is 0.02-9%.