Experimental Study on the Hydrodynamics and Mass Transfer Characteristics of Airlift Loop Reactors (ALR)

The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of the airlift loop reactor was studied. The effect of the airlift reactor and ultrasonic wave on the reactor’s gas holdup, liquid circulation velocity, mixing time and overall volumetric mass transfer coefficient respectively with and without the presence of ultrasonic wave is empathetically examined and compared. The experiment has proven that the incorporation of ultrasonic wave has no effect on the gas holdup but has the tendency to gradually decrease the liquid circulation velocity and increase the overall volumetric mass transfer coefficient; the effect on the mixing time is relatively complex. At low gas velocity, low powered ultrasonic wave promotes the radial mixing of fluid; with the increase of ultrasonic power, ultrasonic vibration obstructs the radial mixing of fluid. Therefore, there exists an optimal ultrasonic power. Moreover, the effect of ultrasonic wave on the mixing time gradually decreases with the increase of the superficial gas velocity. Correlations were also proposed for the hydrodynamics and mass transfer characteristics of the reactor.