Fluid dynamics and mass transfer in submerged gas-particle jets

A room temperature model of a submerged gas-particle jet was used to investigate the hydrodynamics and gas-liquid mass transfer in such systems. Air or CO₂ was used to inject particles of silica sand into water. In some cases, the sand was coated with resin to produce a hydrophobic surface. The flow regimes of behavior were observed: In the bubbling flow regime large bubbles of gas are formed and penetrated by a stream of particles which did not entrain gas, and in the steady jet flow regime the gas and particles travel together in a narrow cone. The second flow regime is favored by a high gas velocity, a small particle size, and a high ratio of particles to gas in the jet. The surface characteristics of the injected particles do not appear to affect this transition. A CO₂-NaOH solution model was used to determine the effects of inert particle injection of the rate of mass transfer from gas to liquid. The rate of mass transfer was higher in steady cone jets, because under these conditions, the gas is dispersed into finer bubbles and carried deeper in the bath. Formerly Graduate Student in the Department of Civil Engineering, Mechanics, and Metallurgy, University of Illinois at Chicago