Soil Vapor Extraction can be defined as vacuum enhanced removal of volatile vapors from geologic formations.
The equipment typically used for soil vapor extraction (SVE) applications starts with the vacuum blower or pump. There are several types of vacuum blowers or pumps used for soil vapor extraction but the most common types include Regenerative Blowers, Rotary Lobe Blowers, Rotary Claw Blowers, Centrifugal Fan Blowers and Liquid Ring Pumps. Different types of vacuum blowers or pumps generate different levels of air flow and vacuum. For assistance choosing the appropriate blower or pump for your application, contact one of our trained professionals and also reference our application guide on pilot testing.
The vacuum blowers or pumps can be damaged by the liquid and/or vapor generated by soil vapor extraction so a moisture separator or knockout tank is used to protect the vacuum blower or pump. Depending on the type of vacuum blower or vacuum pump and the levels of vacuum that a particular blower or pump is capable of producing different styles of moisture separators or knockout tanks are used that are rated to handle the appropriate levels of vacuum. Particulate Filters are used to protect the vacuum blowers or pumps from dust, dirt and debris and exhaust silencers are used to quiet them.
Control Panels are necessary to operate the vacuum blower or pump. Controls range from a simple on or off control to advanced programmable logic controllers (PLC) with remote telemetry. Enviro-Equipment Inc. has an UL 508A and 698A licensed control panel shop in house to design, build and troubleshoot your control systems.
Several instruments can be used when extracting soil vapors. A Testo 445 can be used to measure air velocity, percent relative humidity and air temperature. Flame Ionization Detectors (FID) or Photoionization Detectors (PID) can be used to measure hydrocarbon vapor concentration. Magnehelic Gauges or Pressure Transducers can be used to determine influence, or changes in vacuum levels in monitoring wells.
Depending on local or state regulation, the off gas generated by extracting soil vapors may need to be treated. Vapor Phase Carbon and Oxidation are two options for off gas treatment. When using vapor phase carbon for off gas treatment, if the blower’s discharge temperature is above 140F it’s often preferable to use an after cooler to reduce the exhaust temperature for increased efficiency for the carbon treatment. When using an oxidizer, there are two types to consider, thermal and catalytic. Please read our application guide on off gas treatment for more information.
If your soil vapor extraction system generates a significant amount of contaminated groundwater, local or state regulation may require treatment before the liquid can be discharged. Air Strippers, Liquid Phase Carbon and Oil Water Separators can be used for groundwater treatment. Please read our application guide on groundwater treatment for more information.
One way to enhance the effect of soil vapor extraction is by coupling it with air sparging. Air sparging helps volitalize dissolved hydrocarbons so they can be extracted more quickly and easily. For more information on air sparging please read our application guide.
Visit our Soil Vapor Extraction Remediation Systems page to view the new Soil Vapor Extraction remediation equipment that we offer.