Novel Scaling Parameter for Circulating Fluidized Beds

Experimental results of a one-fifth scale cold laboratory model of a circulating fluidized-bed pilot plant for biomass gasification are reported here. Measurements revealed that the solid circulation rate is a function of the superficial gas velocity in the riser and the total mass load in the system. A novel dimensionless scaling parameter introduced describes the dimensionless mass turnover. Experiments were carried out varying both particle diameter, 170 μm ≤ d ≤ 860 μm, and density, 1,480 kg/m³ ≤ ρ_s ≤ 8,900 kg/m³. An excellent prediction for the mass turnover was obtained for mass loads varying from 1 to 15 kg and throughout the whole particle size and density range using the equations derived. Furthermore, the particle-size distribution is a scaling parameter to be matched between a model and an industrial plant. Correspondence concerning this article should be addressed to J. Yates.