Hydrodynamic characteristics of bubble-induced three-phase inverse fluidized bed (BIFB)

A new bubble-induced three-phase inverse fluidized bed (BIFB) is proposed, where particles lighter than water are fluidized downwards by upward flowing gas without net liquid flow due to the reduced net gas-liquid mixture density and the turbulence caused by bubble flow. Key advantages include uniform fluidization of particles, zero or low liquid flowrate, low energy consumption and easy re-fluidization, showing great potential in biochemical, bioprocess, food, environmental and petrochemical industry. In a 0.33 m diameter pilot-scale BIFB column, four flow regimes; initial fluidization gas velocity and complete fluidization gas velocity were identified, using particles of different diameters and densities. A new concept, the fluidization ratio, is devised to best describe the fluidization quality in BIFB. (C) 2019 Published by Elsevier Ltd.