Märkäpuhdistin

Märkäpuhdistin, also known as a wet scrubber, is an air pollution control device. It removes pollutants from a flue gas stream by bringing the flue gas into contact with a scrubbing liquid. The pollutants can be in the form of particulate matter, gases, or both.

The principle of operation involves using a liquid, typically water, to absorb or trap the contaminants. There are various designs for wet scrubbers, including venturi scrubbers, spray towers, and packed bed scrubbers. In a venturi scrubber, the flue gas is accelerated through a constricted section where the scrubbing liquid is injected. The high velocity causes the liquid to break into small droplets, increasing the surface area for efficient pollutant removal. In spray towers, the flue gas passes through a chamber where liquid is sprayed from nozzles, allowing for contact and removal of pollutants. Packed bed scrubbers utilize a bed of packing material, such as rings or saddles, which is wetted by the scrubbing liquid. As the flue gas flows through the packing, pollutants are captured.

Wet scrubbers are effective in removing a wide range of pollutants, including sulfur dioxide (SO2), hydrogen chloride (HCl), particulate matter, and heavy metals. They are commonly used in industrial applications such as power plants, chemical manufacturing, and incinerators. The scrubbing liquid can be plain water, or it can be treated with chemicals like lime or sodium hydroxide to enhance the removal of specific pollutants. The spent scrubbing liquid, which now contains the captured pollutants, is then treated or disposed of appropriately.