ONSET OF GAS INDUCTION, POWER-CONSUMPTION, GAS HOLDUP AND MASS-TRANSFER IN A NEW GAS-INDUCED REACTOR

A newly developed gas-induced reactor, characteristics of having a dra ft tube and dual turbines was studied. This paper presents the effects of operational variables on the onset of gas induction and power cons umption post gas induction. Moreover, gas holdup and mass transfer wer e also investigated. It was found that all the impeller speed, the liq uid level and the impeller diameter had significant effects on the ons et of gas induction and the power consumption post gas induction. Two empirical equations which correlate the onset of gas induction and pow er consumption post gas induction with the operational variables were obtained, being successfully capable of predicting the data. The volum etric mass transfer coefficients (k(L)a) of 0.8-1.2/min and liquid-fil m mass transfer coefficients (k(L)) of 2.5 x 10(-4)-7.5 x 10(-4) m/s w ere also obtained, being comparable to the cited values. Furthermore, regional bubble number and size distributions as well as an unique met hod for determining the gas holdup were also presented. (C) 1997 Elsev ier Science Ltd.