Local hold‐up and liquid velocity in air‐lift reactors

Measurements of local hold‐up and liquid recirculation rate in an air‐lift reactor were performed with two types of gas spargers using a manometric technique. A simple exponential function correlated properly the liquid velocity measured to the gas flow rate. The local hold‐up varied appreciably along the column and showed a maximum in most of the cases. A simple linear relationship correlated the local gas velocity with the total flow rate of the mixture.