Gas entrainment rate and flow pattern in a plunging liquid jet aeration system using inclined nozzles.

Abstract

For an inclined plunging jet aeration system using liquids of low viscosity, the effects of operating conditions on the gas entrainment rate Qg when nozzles having various values of length-to-diameter ratio Ln/Dn were employed were evaluated experimentally. The changes in Qg were related to those in the jet shape before plunging and the liquid velocity distribution at the point where the gas sheath breaks up. An empirical equation was presented to predict the penetration depth Z of bubbles entrained by the diffusing jet. Bubble entrainment behavior was further examined in terms of the liquid velocity distribution in the submerged two-phase region and the size of entrained bubbles.