Axial mixing of liquid in counter-current bubble columns

Axial mixing of liquid in bubble columns with a counter-current now is investigated experimentally. Experiments were conducted in vertical columns 0.07 m in diameter and 4.25 m in height, and 0.15 m in diameter and 2.7 m in height. Air and tap water were used as the gas and liquid phases, respectively. The axial dispersion coefficient of liquid increases with increasing gas and liquid velocities, and is discussed by comparing with model based on the turbulent mixing-length theory, which was de,eloped by,Matsumoto el al., and on the internal recirculating flow model extended by Wachi ef al, in a concurrent bubble column.