Gas-liquid interfacial area and liquid-phase mass transfer coefficient in sieve plate columns without downcomer operating at high gas velocities.

Abstract

Experiments were performed to investigate the gas–liquid interfacial area and the liquid-phase mass transfer coefficient of a two-phase dispersion on sieve plates with hole diameters of 4–12 mm and with free areas of 5.5–50.4% without downcomer. Operation was carried out at high gas velocities using cobalt-catalyzed oxidation of aqueous sodium sulfite solution with air.The two-phase dispersion showed froth regime and transition regime, which is called partially developed spray regimes/mixed froth regimes, depending on the gas velocities. The gas–liquid interfacial area of the two-phase dispersion in the froth regime is influenced by the free area of the plate, whereas no effect of free area is found in the transition regime. The correlations of interfacial area for each regime are given on the basis of the correlation obtained by Zuiderweg under a gas–liquid cross-current condition. Empirical equations for the Sherwood number based on liquid depth are obtained. Using the results of the interfacial area and the mass transfer coefficient, the mass transfer volumetric coefficient can be predicted.