Abstract
A gas-liquid two-phase plunging jet is formed through an ejector type nozzle with a sheet of perforated plate. Absorbers using such a jet have a high gas holdup and a large product of liquid-phase mass transfer coefficient and gas-liquid interfacial area (k¯LA)T. In the present study, the dependence of gas holdup and bubble diameter on nozzle geometry and column diameter was investigated experimentally. An equation for gas holdup was derived based on physical considerations. The mass transfer mechanism for all experimental data was analyzed with a coaxial bi-zonal model. The dependence of liquid phase mass transfer coefficient k¯LT and specific gas-liquid interfacial area aT on column diameter DT was evaluated. Gas holdup was found to be a function of equivalent diameter, de, total energy of the liquid jet, ET, and DT. The behavior of this absorber can be explained using the coaxial bi-zonal model across all data. (k¯La)T for the plunging jet absorber can be enhanced by decreasing DT, while aT showed a weak dependence on DT. Changes in k¯LT were influenced by increasing the ratio of gas-liquid interfacial area in the peripheral annular zone to that in the core zone. Therefore, changes in (k¯La)T against energy loss per unit volume of liquid, ET/VL, was dependent on changes in k¯LT with ET/VL. Design of the plunging jet absorber showed that a nozzle diameter DN = 1 cm and DT = 5 cm were desirable under the experimental conditions.
