INVESTIGATION OF THE GAS HOLD-UP OF OXYGE N AND HYDROGEN IN DIFFERENTAQUEOUS-ELECTROLYTE SOLUTIONS .2. MODELING OF THE GAS HOLD-UP

To date models used to describe the gas hold-up in a homogeneous bubbl e flow have not considered the coalescence behaviour of the gas bubble s. in several studies, however, it is shown that coalescence has a str ong effect on gas hold-up. Using the results of experimental investiga tions, a new model was developed to calculate the gas hold-up in diffe rent electrolyte solutions. The coalescence in this model is considere d as a reaction of two bubbles. The reaction rate constant of the coal escence reaction is the main parameter for predicting the gas hold-vp for different solutions and gases. It not only depends on the type and concentration of the electrolyte, but also on the kind of gas.