Transfer coefficients for a rising swarm of bubbles

An experimental study was performed to determine the mass transfer coefficient for a rising swarm of bubbles in a liquid pool. The experimental study consisted of oxygen absorption to water from bubbles containing a mixture of oxygen/nitrogen, oxygen desorption from water pools, and CO{dollar}sb2{dollar} absorption from bubbles containing nitrogen/carbon dioxide into a water pool containing 10{dollar}sp{lcub}-2{rcub}{dollar} M KOH.; Experimentally measured liquid-side mass transfer coefficients were used to validate proposed engineering correlations defining the mass transfer coefficient for a swarm of bubbles. Oxygen absorption/desorption data were best predicted when the correlation for a drop rising in a liquid pool with flow separation near the drop waist (Nu = 0.6Pe{dollar}sp{lcub}1/2{rcub}{dollar}) was used in combination with a bubble size distribution consisting of two, large and small bubble, size groups.; CO{dollar}sb2{dollar} absorption study results showed that in addition to bubble size distribution, the pool pH has a direct effect on the mass transfer rate due to existence of chemical equilibrium among the species formed as a result of the carbon dioxide reaction with water. The results reconfirmed the applicability of the correlation validated against the oxygen test study data for the liquid-side mass transfer coefficient.; Experimental data reported in the literature for elemental iodine scrubbing by water pools were used to validate the gas-side mass transfer coefficients. The proposed model accurately predicted the experimental data, however, due to high mass fluxes associated with the gas-side controlled process and lack of time dependent data, the validation procedure may be questionable.; An experimental study was conducted to determine the swarm bubble size distribution. Parameters considered were gas flow rate, pool depth, and swarm location in the pool. Video-tapes and photographs were used to measure the size of the bubbles in swarm rising in the pool. These measurements were used to correlate the mass fraction of the gas that is carried in the large bubbles, present in the swarm. A statistical study was then performed and correlations were developed for prediction of the bubble size.