HYDRODYNAMIC STUDY OF TWO AND THREE-PHASE AIRLIFT REACTORS

The experimental investigations on the hydrodynamic performance of both two and three-phase gasliquid-solid in 171 and 135-liter external loop airlift reactors have been conducted. the purpose of thework includes the development of new hydrodynamic correlations concerning the riser and down-comersections of the airlift reactors. in the two-phase study, tap water is used as the newtonian medium. while in the three-phase study different quantities of paper are added in xanthan solution of water. the gas holdupin the riser (er) and in the down-comer (ed), the liquid circulation velocity in the riser (vlr) and in the down-comer (vld) are determined as function of the superficial gas velocity (vgr).the ratio of the cross-sectional area of the down comer to the riser (ad/ar) is used as a scale-up factorto differentiate the reactors (i.e. ad/ar = 0.54 meant the larger reactor, ad/ar = 0.25 meant the smallerreactor). the effect of the (ad/ar) factor on the (er, ed, vlr) parameters have been studied for different systems.the dependency of down-comer gas hold-up on the riser hold-up for different systems is computed and the new correlations were obtained by means of linear fit of ed versus er.in general, the addition of different quantities of paper on air-water- xanthan system leads to significant simulation of gas hold-ups and liquid circulation velocities for the study of the three-phase aspects of the hydrodynamics of airlift reactors.