Thermal Remediation Vapor Covers: Why & How

Steffen Griepke Nielsen, Technical Director, Thermal Conductive Heating and Steam Enhanced Extraction

Summary

While it may be tempting to reduce overall project cost of an in situ thermal remediation (ISTR) project by not properly insulating the treatment zone, one must consider what compromises are being made to the overall treatment success by not insulating the treatment area. In addition one should factor the weight of the remedy success with the potential cost being saved.

Thermal conduction heating (TCH), steam enhanced extraction (SEE), and electrical resistance heating (ERH) are all thermal technologies widely used to effectively clean up a variety of chemicals from different geological settings, ranging from tight clays to permeable sands.

The depth to the top of the contaminated area, contaminant type, vadose zone, geology, vapor extraction strategy, and location of the water table are all factors influencing whether the surface of a thermal site will need to be insulated during a thermal remedy.

The main purposes of a vapor cover are to:

  • limit the infiltration of rainwater into the treatment area,
  • create a vapor tight seal to the atmosphere, and most importantly,
  • reduce the loss of heat from the shallow treatment zone during thermal operations.

During this webinar Steffen Griepke, Cascade Thermal's Technical Director for TCH and SEE, will focus on design considerations related to the selection of vapor caps for different thermal sites. Guidelines will be presented related to the choice of cap material for different heating scenarios, based on the site-specific chemicals of concern, and the shallow soil temperatures needed for proper treatment. Scenarios where no vapor cap is needed will also be presented. The discussions will be based on field data from sites with target temperatures ranging from 100°C to > 300°C.

Date and Time

October 17, 2018
10:00 AM PDT / 1:00 PM EDT

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