Hydrodynamics of a three-phase external-loop airlift bioreactor

The e!ect of the distributing plate ori"ce diameter, air#ow rate, solids loading and solids density on the hydrodynamic characteristics* gas holdup, circulation time and liquid velocity * of a three-phase external-loop airlift reactor was characterized. It was observed that the gas distributor has a small e!ect on riser gas holdup, circulation time and downcomer liquid velocity. On the contrary, the air#ow rate, solids loading and solids density signi"cantly a!ect the hydrodynamic characteristics of the external-loop airlift reactor. A previously described model was used to estimate simultaneously both the riser gas holdup and the downcomer linear liquid velocity. The model simulated with high-accuracy experimental data obtained with three di!erent distributing plate ori"ce diameters, two solids density and solids loading up to 30% (v/v). ( 2000 Elsevier Science Ltd. All rights reserved.

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