Baffle spray scrubbers are a technology for air

pollution control Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

. They are very similar to

spray tower A spray tower (or spray column or spray chamber) is gas-liquid contactor used to achieve mass and heat transfer between a continuous gas phase (that can contain dispersed solid particles) and a dispersed liquid phase. It consists of an empty c ...

s in design and operation. However, in addition to using the energy provided by the spray nozzles, baffles are added to allow the gas stream to atomize some liquid as it passes over them. A simple baffle scrubber system is shown in Figure 1. Liquid sprays capture

pollutant A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like o ...

s and also remove collected particles from the baffles. Adding baffles slightly increases the

pressure drop Pressure drop is defined as the difference in total pressure between two points of a fluid carrying network. A pressure drop occurs when frictional forces, caused by the resistance to flow, act on a fluid as it flows through the tube. The main de ...

of the system. This type of technology is a part of the group of

air pollution Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different typ ...

controls collectively referred to as

wet scrubber The term wet scrubber describes a variety of devices that remove pollutants from a furnace flue gas or from other gas streams. In a wet scrubber, the polluted gas stream is brought into contact with the scrubbing liquid, by spraying it with the ...

s. A number of wet-scrubber designs use energy from both the gas stream and liquid stream to collect pollutants. Many of these combination devices are available commercially. A seemingly unending number of scrubber designs have been developed by changing system geometry and incorporating vanes, nozzles, and baffles.

Particle collection

These devices are used much the same as

s - to preclean or remove particles larger than 10 μm in diameter. However, they will tend to plug or corrode if particle concentration of the exhaust gas stream is high.

Gas collection

Even though these devices are not specifically used for gas collection, they are capable of a small amount of gas absorption because of their large wetted surface.

Summary

These devices are most commonly used as precleaners to remove large particles (>10 μm in diameter). The

s across baffle scrubbers are usually low, but so are the collection efficiencies. Maintenance problems are minimal. The main problem is the buildup of solids on the baffles.
Table 1 summarizes the operating characteristics of baffle spray scrubbers. US EPA Air Pollution Training Institute
developed in collaboration with North Carolina State University, College of Engineering (NCSU)

Bibliography

*Bethea, R. M. 1978. Air Pollution Control Technology. New York: Van Nostrand Reinhold. *McIlvaine Company. 1974. The Wet Scrubber Handbook. Northbrook, IL: McIlvaine Company. *Richards, J. R. 1995. Control of Particulate Emissions (APTI Course 413).

U.S. Environmental Protection Agency The Environmental Protection Agency (EPA) is an Independent agencies of the United States government, independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon pro ...

. *Richards, J. R. 1995. Control of Gaseous Emissions. (APTI Course 415). U.S. Environmental Protection Agency. *U.S. Environmental Protection Agency. 1969. Control Techniques for Particulate Air Pollutants. AP-51.

References

Institute of Clean Air Companies
{{Webarchive, url=https://web.archive.org/web/20201001153344/https://www.icac.com/ , date=2020-10-01 - national trade association representing emissions control manufacturers Pollution control technologies Air pollution control systems Wet scrubbers Liquid-phase and gas-phase contacting scrubbers