Holdup Studies in IFBR for Wastewater Treatment

In the present investigation, bed porosity and phase holdups in a three-phase inverse fluidized bed reactor are determined for Newtonian (aqueous solutions of glycerol) and non-Newtonian (aqueous solutions of carboxy methyl cellulose) systems using low-density polyethylene (LDPE) and polypropylene (PP) particles of different diameters (4, 6 and 8 mm). The gas holdup (εg) and porosity (ε) in the three-phase inverse fluidized bed reactor was observed to increase with an increase in Ug. The solid holdup (εs) and liquid holdup (εl) decreased as the Ug increased for a fixed Ul. The liquid holdup increased with increase in Ul and the gas holdup increased with increase in particle diameter. The effect of liquid concentration on gas holdup and liquid holdup are also studied. Empirical correlations are developed to determine the phase hodups. Modified drift flux model have been presented for the prediction of the phase holdups (solid, liquid and gas) for Newtonian and non-Newtonian systems.