BUBBLE DYNAMICS AND OXYGEN-TRANSFER IN A SPEECE CONE

A model is developed that predicts bubble dynamics and oxygen transfer in a Speece Cone. The model is based on differential mass balances fo r both gas and water and requires a knowledge of cone dimensions, wate r flow rate, depth to the cone, and initial bubble diameter produced b y the oxygen diffuser. The model calculates the oxygen transfer, nitro gen stripping, and gas-phase holdup within the cone. Experimental data for a Speece Cone have not been published; however, a modified versio n of the model is tested using data obtained from a hydrodynamically s imilar full-lift hypolimnetic aerator with good results. This process model, when coupled with a suitable cost model, should prove useful in the preliminary design and economic optimization of Speece Cone oxyge nators. (C) 1998 IAWQ. Published by Elsevier Science Ltd.