Dual Phase Extraction (DPE) can be defined as a process that uses vacuum pumps or blowers to remove various combinations of contaminated groundwater, separate-phase petroleum product, and hydrocarbon vapor from the subsurface. Extracted liquids and vapor are treated and collected for disposal per state regulation. A few other terms for Dual Phase Extraction include Multi Phase Extraction (MPE), vacuum enhanced extraction or bio slurping. Dual Phase Extraction is often performed by a mobile system and may be called Mobile Multi Phase Extraction (MMPE) or Aggressive Fluid Vapor Recovery (AFVR). Enviro Equipment rents and sells mobile dual phase extraction trailers.
The equipment typically used for dual phase extraction (DPE) applications starts with the vacuum blower or pump. There are several types of vacuum blowers or pumps used for dual phase extraction but the most common types include Rotary Lobe Blowers, Rotary Claw 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 dual phase extraction so a moisture separator or knockout tank is used to protect the vacuum blower or pump. 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 with dual phase extraction. A Testo 445 or Dwyer Thermal Anemometer can be used to measure air velocity, percent relative humidity and air temperature. Flame Ionization Detectors (FID) or Photo Ionization 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 dual phase extraction 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.
Depending on local or state regulation, the groundwater generated by dual phase extraction may require treatment before it 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.
Visit our Dual Phase Extraction Remediation Systems page to view the new Dual Phase Extraction remediation equipment that we offer.