Hydrodynamic similarity in liquid–solid circulating fluidized bed risers

Hydrodynamic similarity in the liquid–solid circulating fluidized bed systems under different operating conditions was investigated. The experimental data obtained from this work and in the literature show that when the scaling parameter, Gs/(ρpjl), is modified as (ja/jl), ratio of auxiliary liquid velocity to total liquid velocity, a detailed hydrodynamic similitude of the liquid–solid circulating fluidized risers under different operating conditions can be achieved. Furthermore, the experimental results from different liquid–solid flow systems show that as long as (ja/jl)0.3 remains constant, the solid concentrations in the zone of CFB risers increase linearly. Archimedes number, Ar, Galileo number and Froude number, FrD were used to use the modified scaling parameter, (ja/jl), without power. Experimental results show that as long as Ar−0.07(ja/jl), Ga−0.07(ja/jl) and FrD−0.07(ja/jl) is maintained, the similarity of the liquid–solid circulating fluidized bed riser is obtained using the new similarity parameter without using power. The empirical similarity parameter, (ja/jl), appears to have incorporated the effects of operating parameters (Gs and jl).