Wet scrubbers are used for cleaning air and other gases of various pollutants and dust particles or substances considered harmful to the environment, and which may be removed or neutralized.
A Wet Scrubber is an air pollution control device which uses a liquid to remove contaminants from a gas stream. The removal process is achieved by bringing the gas stream into contact with the scrubbing liquid, which facilitates mass transfer of the contaminants into the liquid.
Wet scrubbing works via the contact of target compounds or particulate matter with the scrubbing solution. Solutions may simply be water (for dust) or solutions of reagents that specifically target certain compounds. Process exhaust gas can also contain water-soluble toxic and/or corrosive gases like hydrochloric acid (HCl) or ammonia (NH3). These can be removed very well by using a wet scrubber.
The removal efficiency of pollutants is improved by increasing residence time in the scrubber or by the increase of surface area of the scrubber solution by the use of a spray nozzles, packed towers or aspirators. Wet scrubbers may increase the proportion of water in the air, resulting in a visible stack plume, if the air is discharged to atmosphere. Industrial applications for the control of odours and VOC emissions include exhaust air streams from textile heat-set stenters, printing, anaerobic digesters, waste transfer stations and food processing applications.