Effect of Stirring Condition and Bath Shape on Degassing Behavior in Water Model

Abstract

Degassing rate constant of CO₂ in gas-stirred or mechanically stirred NaOH aq. system was studied by the water model experiments. Effects of stirring gas-flow rate, pressure of atmosphere, speed of rotor and shape of bath on rate constant, K, was investigated.
The following results were obtained:
(1) Rate constant, K, increased with increase of gas-flow rate, speed of rotor and with decrease of pressure of atmosphere. And K was correlated with stirring power ε and ε/A.
(2) Calculated K using a single bubble model and surface reaction model showed a good agreement with observed K. Ratio of Ks at free surface to overall rate constant K was correlated with ratio of free surface area to volume.
(3) Volumetric coefficient at free surface in RH shape was estimated three times as large as that in Ladle shape.