Abstract
Gas hold-up in water and Castor oil, which were agitated separately by four disc type impellers, is compared on the basis of equal specific power dissipation (PG/V). It is noted that unlike in water, gas hold-up in Castor oil is time dependent, and also strongly influenced by impeller design. Further, the gas hold-up values in Castor oil are generally higher than those observed in water, and unlike in water, decrease with increasing (PG/V). These observations, which appear anomalous in the context of some earlier publications, are explained by considering the hold-up in Castor oil in terms of contributions from large and tiny bubbles.
