Definition - What does Wet Scrubber mean?
Wet scrubbers are devices that form an air pollution control system, installed in industries to remove certain compounds, particles and gases from the exhaust streams.
This system uses water and other additives to trap the gaseous pollutants. The removal of the gases from power plant emissions enables the gases to be recycled, generating energy, and preventing corrosion of the machines and mechanisms involved in the recycling process. A combination of venturi and centrifugal technology are used to ensure that the air is thoroughly cleaned.
Wet scrubbers are also known as packed-bed scrubbers or absorbing towers.
Corrosionpedia explains Wet Scrubber
Wet scrubbers use a counter flow technology to ensure that the water in the vertical tank or tower maintains contact with the gaseous stream of exhaust gases. The tank also has packing which filters the gases as well as the water so that more contact is achieved. The process is simple since water falls under the influence of gravity, whereas gases are pumped as they rise up the vertical tank. The process ends when the collected mixture is further filtered and extracted into disposable solid forms.There is also the use of venturi in this system to improve gas-to-water contact. The most important step is the separation of the gas steam and the scrubbing mixture.
More reactions occur at the effluent tank due to the exposure of the pollutant gases with the additives present in the water. The use of absorption in the spray tower scrubber system is a form of wet scrubber technology since droplets are used in the process. The efficiency of the system is determined by the inspection of the gaseous streams and the amount of particulate removed. Selection of the wet scrubber technology to be used depends on:
- Space required or volume of gas
- Temperature of the gas
- Types of pollutants to be removed
- Efficiency required
Corrosion regularly occurs in this type of scrubbing system due to the formation of acids and presence of abrasion where high velocities are produced. Control of pH and other relevant solutions are used to prevent the wearing of equipment through corrosion and abrasion.