Wet Scrubber

A wet scrubber is an air pollution control device that cleans flue gas or other process gas of pollutants and dust by bringing the gas into contact with a scrubbing liquid, typically water, which is especially effective at removing water soluble toxic or corrosive gases such as hydrochloric acid or ammonia from an exhaust stream. Scrubber performance improves by increasing the gas residence time inside the unit or by increasing the scrubbing liquid surface area, using a spray nozzle, a packed tower or an aspirator to do so. A specialized condensing wet scrubber can also recover thermal energy from hot exhaust gas, drawing more than 2 gigajoules, about 560 kilowatt hours, of latent heat per ton of water condensed, energy that can be captured for uses such as district heating, though an ordinary wet scrubber trades this benefit for a visible plume of water vapor if its treated gas is sent up a stack.