Author(s): J. P. Giovannettone
Linked Author(s):
Keywords: Two-phase flow; Hypolimnetic aerator; Bubble plume; Bubble column; Air-lift reactor; Oxygenation; Destratification; Void ratio; Sauter mean bubble diameter
Abstract: Oxygenation of a lake or reservoir through bubble plumes and hypolimnetic aerators can be beneficial to the aquatic and animal life in the water body and to humans living nearby. Bubble plumes can be partially simulated in the laboratory or in the field using a bubble column (BC) and hypolimnetic aerators by an airlift reactor (ALR). Tests should be performed to make the oxygenation process the most efficient at the least cost, but in the past these tests have been performed in columns and reactors that are significantly shallower than a typical lake or reservoir. This problem is eliminated by studying the hydrodynamics of two- phase gas-liquid flow inside a deep ALR. It was modified to be run as either an external air- lift reactor (EALR) or a bubble column. Several combinations of operating conditions were used to determine the effects of sparger type, column type, and superficial gas velocity on void ratio and bubble diameter. The results are compared to studies that have performed similar experiments in smaller columns. Ongoing experiments on gas transfer rates are underway. The combination of these experimental programs will result in design characterizations of deep ALR’s and BC’s that can be applied to most lakes and reservoirs.
Year: 2005