Experimental Study and Theoretical Model Described Transition Regime Parameters and Hydrodynamic Parameters in a Gas-Liquid Dispersion Column

Abstract

Experimental study of total gas hold-up, bubble diameters and rise velocity ofthe swarm of bubbles, and regime transition point in dispersion column. Theexperimental runs were carried out in two perspex columns of 7.5 cm and 15 cm insidediameter. The present work investigated the effect of two system of two-liquid phase(air-water, and air-aqueous-n-propanol solution) in the range (0.05-0.7Wt%),superficial air velocity in the range (0.025-0.3 cm/s) and two air distributor plates of1.5 mm diameter holes (i.d.= 7.5 cm, holes=36 and free area=1.4%, and i.d.= 15 cmholes=121 and free area=1.2%). In this paper, a Krishna et al., 1999 model has beenimproved, and the combination of this improved model with derived drift flux modelhave been described the hydrodynamics of dispersion column operating inhomogeneous and heterogeneous flow regimes (i.e. transition regime parameterest ransand Utrans ). Photographic technique was used by taking three pictures in different view(different angle) of the dispersion column, to measure the hydrodynamic parameters.From the experimental data, it was found that the addition of a small amount of npentanolto distilled water and varying dispersion column diameter, is the main factorthat affects, the transition flow regime. Also the experimental results show that thevalues of total gas hold-up for air-aqueous n-pentanol solution system are greater thanthe values for air-water system, but the values of total gas hold-up decrease withdispersion column diameter for two systems.The experimental data show that the values of total gas hold-up and superficial airvelocity at transition regime varied with the weight percent of n-pentanol by fitting ofsecond order polynomial regressions for the two dispersion column diameters: