Mass transfer in a bubble column



The effects of gas and liquid flow rates and of seal height on the absorption of carbon dioxide in water have been studied. The gas bubbles were formed from 1/16 in. orifices, with both single and multiple hole arrangements.

Bubble frequencies were measured using a high speed motion picture camera and are reported graphically as a function of gas flow rate. At high flow rates, considerable breaking up of the bubbles was observed.

Because of the difficulty of estimating interfacial areas, the transfer data were reported using the product of the transfer coefficient and the interfacial area, KLa. For single orifices KLa was found to vary directly with the gas rate, was only slightly dependent on liquid rate and was almost independent of seal height after due allowance for end effects. With multiple hole plates having 5/8 in. spacing, there was no appreciable change in the transfer rate per hole until the hole density exceeded 1.5 per square inch, after which the rate decreased slightly.

End effect contributions to transfer are also reported.