Basic hydrodynamics of a pilot-scale liquid-solid inverse fluidized bed

A pilot-scale liquid-solid inverse fluidized bed (LSIFB) with 0.33 m in inner diameter and 3.0 m in height was designed and installed. Basic hydrodynamics were investigated experimentally using particles with different diameters and densities. The minimum fluidization velocity increases with the increase of particle diameter and the decrease of particle density and is independent of particle loading. Forty eight sets of data on minimum fluidization velocities from the investigation combined with the literature were collected and summarized to establish an empirical equation by modifying the Wen and Yu equation. The modified equation can predict effectively the minimum fluidization velocity across a wide range of Archimedes number. The bed expansion ratio increases with liquid velocity and particle density but decreases with the increase of particle diameter. Based on the bed expansion characteristics, an empirical equation was proposed by correlating Archimedes number and Reynolds number to predict successfully the bed expansion.