Packed bed wet scrubbers are commonly used to remove water soluble compounds and eliminate any particulates (PM) from the polluted gas stream. It consists of a chamber containing layers of variously-shaped packing material, to provide a large surface area for liquid-particle contact. A scrubbing liquid (in general water or a solution with chemicals according to the contaminants) is sprayed with nozzles on the packed material.
Such system allows the continuous formation of scrubbing liquid droplets; thus, the liquid surface is incessantly regenerated. The polluted gas stream flows up to the chamber (counter current to the liquid) and the particulates and soluble gas molecules come in contact with the film of scrubbing liquid on the packing and then removed by either absorption or chemical reactions with the scrubbing liquid. The liquid recirculates in the system and it is removed only when it is saturated with pollutants.