Thermal Desorption soil Remediation Unit

Application

Thermal desorption soil remediation unit. Stationary facility designed to remediate 75 tons/hour of various hydrocarbon contaminated soils, including heavy fuel oils. The process consists of a counterflow rotary desorber (1,000ºF) followed by a rotary mixer cooler, cyclone, fabric filter collector, heat exchanger, and thermal oxidizer (1600ºF). The on-line cleaning pulse-jet baghouse utilizes 294 GORE® membrane/Teflon® B fiberglass fabric filter bags to control PM emissions. Inlet grain loading is estimated to vary between 10-50 gr/acf @ 25,000 acfm @ 380ºF, with an air-to-cloth ratio of 3.25 fpm.

Results

Analytical testing of soils before and after treatment, reveals soil contamination levels up to 20,000 ppm TPH being remediated to levels below 10 ppm TPH.

Since the GORE® membrane filter bags were installed (prior to initial startup), the baghouse pressure differential has operated between 4-5" w.g., depending on the type of soil remediated. The GORE® membrane/Teflon® B fiberglass fabric filter bags allow the facility to operate continuously at baghouse temperatures up to the filter media's maximum operating temperature of 500ºF. This flexibility is advantageous when remediating difficult and heavily contaminated soils, where complete hydrocarbon volatilization requires higher desorber and baghouse temperatures. This higher baghouse temperature allowance also prevents the condensation of hydrocarbons within the collector.

Compliance testing done six months after startup, revealed an outlet emission level approximately 15% lower than the required maximum particulate emission limit.