Fume air scrubbers are light duty wet scrubbers used for air pollution control. The term “fume scrubber” was made popular by the metal finishing industry, since the pollutants emanating from the open-top dip tanks were generally referred to as “fumes.” Fumes may consist of solid or liquid aerosols and/or vapors. Most of the dip tanks used in various metal finishing processes – such as anodizing, brightening, cleaning and plating – produce airborne vapors and liquid aerosols (mists).

Vapors are produced by virtue of one or more components in the bath having a high volatility. Many metal finishing processes run at elevated temperature, which increases the volatility of the bath constituents. Mists are generated either by mechanical agitation of the liquid in the bath or by bubbles forming and bursting as they escape from the liquid surface during an electrochemical process. Mist formation due to an electrochemical process leads to a much finer aerosol than that formed by mechanical agitation.

Fume air scrubbers generally incorporate nominal packed beds. They may use recycled water or water with a chemical additive such as sodium hydroxide. They are available in vertical counterflow or horizontal crossflow configuration. A variety of construction materials are also available, such as PVC, CPVC, polypropylene and FRP.