Bubble columns terminal rise velocity

Fig. 24. Effect of bubble diameter-terminal rise velocity on transitions bubble columns [oi = 0.5, Cv = 1.0, m = 1.9].

In bubble columns, the estimation of parameters is more difficult than in the case of either gas-solid or solid-liquid fluidized beds. Major uncertainties in the case of bubble columns are due to the essential differences between solid particles and gas bubbles. The solid particles are rigid, and hence the solid-hquid (or gas-solid) interface is nondeformable, whereas the bubbles cannot be considered as rigid and the gas-liquid interface is deformable. Further, the effect of surface active agents is much more pronounced in the case of gas-liquid interfaces. This leads to uncertainties in the prediction of all the major parameters such as terminal bubble rise velocity, the relation between bubble diameter and terminal bubble rise velocity, and the relation between hindered rise velocity and terminal rise velocity. The estimation procedure for these parameters is reviewed next. 

Gogoi and Dutta (1996) proposed the Cliff-Grace-Webber con elation for the terminal bubble rising velocity for turbulent slurry bubble columns (Cliff et al., 1978 Shall et al., 1982) ... 

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