Holdup and Flow Behavior of Fluidized Solid Particles in a Liquid-Solid Circulating Fluidized Bed

Characteristics of holdup and flow behavior of fluidized solid particles were investigated in a liquid-solidcirculating fluidized bed (0.102 m × 3.5 m). Effects of liquid velocity (UL), particle size (dP) and solid circulation rate(GS) on the solid holdup, overall particle rising velocity, slip velocity between liquid and particles and hydrodynamicenergy dissipation rate in the riser were examined. The particle holdup increased with increasing dP or GS but decreasedwith increasing UL. The overall particle rising velocity increased with increasing UL or GS but decreased with increasingdP. The slip velocity increased with increasing UL or dP but did not change considerably with GS. The energy dissipationrate, which was found to be closely related to the contacting frequency of micro eddies, increased with increasing dP, GSor UL. The solid particle holdup was well correlated with operating variables such as UL, dP and GS.