Scrubbers are air pollution control devices that help cleanse the emissions coming out of an incinerator's smoke stack. Hot exhaust gas comes out of the incinerator duct and scrubbers help to wash the particulate matter (dust) resulting from the combustion out of the gas. High efficiency scrubbers literally scrub the smoke by mixing dust particles and droplets of water (as fine as mist) together at a very high speed. Scrubbers force the dust to move like a bullet fired at high velocity into the water droplet. The process is similar to the way that rain washes the air.

Scrubbers can also be used as absorbers. Absorption dissolves material into a liquid, much as sugar is absorbed into coffee. From an air pollution standpoint, absorption is a useful method of reducing or eliminating the discharge of air contaminants into the atmosphere. The gaseous air contaminants most commonly controlled by...