Baffle spray scrubbers are a technology for air pollution control. They are very similar to spray towers 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 effect, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oi ...

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

pressure drop Pressure drop (often abbreviated as "dP" or "ΔP") 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 i ...

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

air pollution Air pollution is the presence of substances in the Atmosphere of Earth, air that are harmful to humans, other living beings or the environment. Pollutants can be Gas, gases like Ground-level ozone, ozone or nitrogen oxides or small particles li ...

controls collectively referred to as

wet scrubber The term wet scrubber describes a variety of devices that remove pollutants from a Industrial furnace, 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 sp ...

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 spray towers - 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. *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