Wet scrubbers use a liquid to remove solid, liquid, or gaseous contaminants from a gas stream. The scrubbing liquid performs this separation by dissolving, trapping, or chemically reacting with the contaminant.
Usually the wet scrubber consists of a vertical vessel containing packing materials such as rings, saddles, etc. Water is sprayed across the top of the bed and trickles through the packing material. Gas enters near the bottom and contaminants are removed as the gas stream moves upward through the water-washed packing. Horizontal configurations are also available.
The cleaned gas stream passes through a mist eliminator near the outlet where entrained moisture is removed prior to discharge. Scrubbing liquor is collected at the bottom. A portion is usually recycled to the inlet, and the balance discharged to the sewer.
Wet scrubbers are equipped with dosing pumps, recirculation pumps, fans, chemical sensors and controllers, blowdown automated valves, control panels.
Wet scrubbing technologies can be used where medium to high air flows and medium to very high concentrations of pollutants are present. They have the advantage of being able to operate at much higher temperatures than dry scrubbers and and have the ability to remove particulate pollutants as well.
Their field of applications is extensive and they can be used for removal of gaseous, odorous and toxic pollutants in in almost any medium to large scale industrial and commercial installation. For maximum removal efficiency they can be combined with a final dry scrubbing stage.