Bubble Towers

Gas is dispersed into the liquid phase in the form of fine droplets. Bubble towers are used with systems in which the liquid phase controls the rate of mass transfer; that is, the absorption of relatively insoluble gases. Refer to Fig.(6-a).

Spray Towers

Resistance to transfer within the gas phase is reduced by the swirling motion of the falling liquid droplets. Spray towers are used for mass transfer of highly soluble gases where the gas-phase resistance normally controls the rate of mass transfer. Refer to Fig.(6-b).