Article: AGITATED VESSEL MASS TRANSFER
Mass transfer in agitated vessels usually involves dispersed gases absorbing into and often reacting with a continuous liquid phase, e.g., in oxidation or chlorination. Interfacial area and contact time depend on the operating conditions. Moderately high impeller speeds are needed to recirculate rising gas to the impeller or to carry bubbles down to the bottom of the vessel, Figure a and Figure b. Very high gas rates, or insufficient impeller speeds, can lead to the pumping action of the agitator being overwhelmed by buoyancy forces, a condition known as flooding, Figure c.