Client: Tetra Tech (Formerly Foster Wheeler Environmental)
Location: Philadelphia, PA, USA
Background: Tetra Tech uses two (2) Chameleon Thermal Oxidizers to treat off-gas from soil vapor extraction of contaminated ground water.
Waste Description: The contaminants included a wide range of organics.
Solution: SVE operations generate high levels of organics in the first phase of remediation. Over years, as the remediation takes affect, the organic concentrations generated by the process are significantly reduced. As such, the best technology for the first phase of remediation is a recuperative thermal oxidizer. Over time, however, the cost of operating a recuperative thermal oxidizer becomes prohibitive as the organic concentrations are reduced. In the latter phases of remediation, a recuperative catalytic oxidizer is the most efficient design solution. To provide this customer with the flexibility needed, Air-Clear developed the Chameleon Series of oxidizers which can easily be converted from a recuperative thermal oxidizer to a recuperative catalytic oxidizer. This saves significant capital and operational costs for the customer.
Process Equipment: The contaminated vapors from the SVE process enter the a heat exchanger where the temperature of the process gas is raised prior to entering the thermal oxidizer combustion chamber; fuel use is substantially reduced by using a heat exchanger to “preheat” the waste gas entering the combustion chamber. A catalyst support grid is part of the integral design, allowing the insertion of catalyst at a later time to reduce operating costs when inlet concentrations are reduced. In addition, a hot bypass damper was included to regulate combustion chamber temperatures during the initial high concentration remediation phase.