Wet Scrubbers

Wet Scrubbers

 Depending upon the specific gas and contaminant combination, the process stream from the wet scrubber is either forced through a liquid spray or through a pool of scrubbing solution. A properly configured wet scrubber can have a removal efficiency rate as high as 95%. This form of air pollution control can operate at various temperatures and moisture contents, allowing for such efficient decontamination of a process stream in a number of environments. The versatility of wet scrubbers makes them popular in construction, fertilizer, steel mill, power generation, paper and pulp, manufacturing and propane or natural gas related industries. Pollutants produced in these environments, such as volatile organic compounds, hydrocarbon and solvent fumes can have serious environmental and biological ramifications if not properly disposed of. For this reason the EPA and other organizations encourage and even require the use of wet scrubbers and other emission control systems.

Though configurations and operations may differ significantly, the basic components of wet scrubbers are similar across the industry. Every arrangement needs duct work and a fan or pump system to draw or push the polluted gas into the collection area or chamber. A pump is also required to pressurize the liquid scrubbing solution or air stream depending upon the specific configuration. The two most basic types of wet scrubbers are spray and pool scrubbers. In the former, pressurized cleaning solution is sprayed into the moving air stream. The liquid attracts heavier particulates causing them to disengage from the gas and instead attach to the liquid which then collects in a chamber. Used liquid is cleaned and often returned for reuse. A pool scrubber requires a saturation chamber. The gas stream is forced through this pool of scrubber solution which collects and binds contaminants while allowing the air stream to pass. Chemical solutions may also be used in either instance to destroy or reconfigure harmful pollutants as needed. Additional filters can be added both before and after scrubbing for increased efficiency. Pre-filters are often employed to enhance efficiency as they collect larger pollutants, allowing the scrubber to focus more keenly on smaller particulates. Final filters may also be used at the exhaust end of wet scrubbing. Like the solution, the clean air may be returned to circulation, though it is commonly expelled into the atmosphere. Although permanent mounted industrial wet scrubbers were once the norm, scrubbers have also become smaller, more portable and even mobilized devices for localized cleansing.