Bubble Column: an OpenFOAM® simulation

Bubble columns are useful processing units to contact gas and liquid for inter-phase mass transfer and chemical reactions. They have been applied in chemical, biomedical, pharmaceutical, petrochemical, waste-water treatment and other industries. Their construction is simple: a vertical column filled with liquid (mostly water) and a gas entering from bottom through a sparger. The liquid can fed (continuous operation) from top or bottom.

Since they provide high contact surface between phases, they are good candidates where mass transfer/heat transfer is an limiting factor. In addition, low shear rate (gentle operation) of fluid in this column makes it a very good candidate as the reaction medium for shear-sensitive materials such as algae and bacterial components. The design of bubble columns requires deep knowledge about gas holdup, bubble size and residence time of phases in the column.

Here you see an animation of bubble column operation. The animation shows the gas phase velocity field and phase holdup. The simulation have been performed using OpenFOAM. You can find a tutorial on how to simulate bubble columns using OpenFOAM here. The simulation is 2D and column dimensions are 0.26 m x 2 m. Superficial air velocity (300 K and atmospheric pressure( is 0.05 m/s.

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