Effects of Height to Diameter Ratio and Aeration rate on Liquid Mixing and Hydrodynamic Properties in a Bubble Column
Document Type: Full article
Abstract
"> Experimental measurements of overall gas holdup (εg), residence time distribution(RTD) and liquid mixing time (tm) have been carried out in an air-water system in a 17lit bubble column with an 11 cm diameter, over a wide range of superficial gas velocity(0.14-1.46 ms-1) and height to diameter ratio (1.36-8.84). The bed expansion methodwas used to obtain holdup values and the change of slope related to εg versussuperficial gas velocity (Usg) indicated the transition point from homogeneous toheterogeneous regime at Usg= 0.7-0.9 ms-1. Besides, the experiments illustrated thatH/D ratio had no effect on holdup values. The axial dispersion model was used withsemi-closed boundary conditions for prediction of RTD, and hence, the axial dispersioncoefficients (Dax). Moreover, fitting results of the model and experimental RTD curvesachieved from tracer injection method attained the model parameter, Dax , in three H/Dratios of 4.73, 6.36 and 8.84. Results showed that an elevation in H/D ratio, caused arise in Dax. On the other hand, the mixing time data declined with an increase in Usg;however enhancement of H/D ratio caused an increase in tm.
(2009). Effects of Height to Diameter Ratio and Aeration rate on Liquid Mixing and Hydrodynamic Properties in a Bubble Column. Iranian Journal of Chemical Engineering(IJChE), 6(3), 46-56.
MLA
. "Effects of Height to Diameter Ratio and Aeration rate on Liquid Mixing and Hydrodynamic Properties in a Bubble Column". Iranian Journal of Chemical Engineering(IJChE), 6, 3, 2009, 46-56.
HARVARD
(2009). 'Effects of Height to Diameter Ratio and Aeration rate on Liquid Mixing and Hydrodynamic Properties in a Bubble Column', Iranian Journal of Chemical Engineering(IJChE), 6(3), pp. 46-56.
VANCOUVER
Effects of Height to Diameter Ratio and Aeration rate on Liquid Mixing and Hydrodynamic Properties in a Bubble Column. Iranian Journal of Chemical Engineering(IJChE), 2009; 6(3): 46-56.