Effect of Various Parameters on the Solids Holdup in a Liquid-Solid Circulating Fluidized Bed

Abstract

A liquid-solid circulating fluidized bed (LSCFB) is operated at high liquid velocity, where particle entrainment is highly significant and between the conventional liquid fluidized bed and the dilute phase liquid transport regimes. In the present work, systematic experiments were carried out in a 0.094 m ID and 2.4 m height laboratory-scale liquid-solid circulating fluidized bed apparatus by using various solid particles and tap water as a fluidizing medium to study the hydrodynamics (axial solids holdup and solids circulation rate). The effects of operating parameters, i.e., primary liquid flow rate in the riser (jf), auxiliary liquid flow rate (ja), total liquid flow rate (jl), particle density (?s), particle diameter (dp) and solids feed pipe diameter (do) on the axial solids holdup distribution were analyzed from the experimental data. Finally, a correlation was developed from the experimental data to estimate average solid holdup in the riser, and it was compared with present experimental and available data in the literature. They agree well with a maximum root-mean-square deviation of 9.12 %.