Soil Vapor Extraction: Carbon Bed Precoolers

AA Series Heat Exchanger

Soils that have been contaminated by chemical spills are often remediated using an air sparge and soil vapor extraction (SVE) process to remove volatile organic compounds (VOCs).  After harmful chemical vapors are extracted from the ground using a vacuum blower, they need to be removed from the air stream, usually by an activated carbon bed filter, before clean air can be exhausted to the atmosphere.  After passing through the vacuum blower, the air stream will have a significantly elevated temperature, which is likely to be unsafe for the downstream filters.  The filter media may be subject to combustion if the gas stream temperature is too high.

Xchanger AA Series heat exchangers are an efficient solution to cool the gas downstream of the blower to within 20°F of the ambient temperature in order to allow contaminants to be removed safely.  The AA Series heat exchangers are generally selected for minimal pressure drop, generally less than 0.25 psi and use a 1 or 2 HP electric motor.

For more information about soil vapor extraction, please see the below literature from the EPA’s website.

A Citizen’s Guide to Soil Vapor Extraction and Air Sparging (PDF)