System for the remediation of highly contaminated soils

Abstract

A low-temperature thermal desorption (LTTD) system remediates highly contaminated soils. The system (1) reduces the concentration of vaporized contaminants exhausted from the primary treatment unit (PTU) and (2) precisely controls the concentration of vaporized contaminants exhausted from the PTU so as to permit the safe oxidization of contaminants in a secondary treatment unit without oversizing the secondary treatment unit or the baghouse. The concentration of vaporized contaminants exhausted from the PTU is reduced by drawing the vaporized contaminants into a low-pressure region of the PTU so as to contact the burner flame and by supplying this area of flame contact with a modulated supply of air to oxidize a designated portion of the vaporized contaminants within the PTU. The concentration and temperature of the remaining vaporized contaminants are controlled by monitoring the concentration of the contaminants in the gas stream exhausted from the PTU, by calculating a lower explosive limit (LEL) of the contaminant concentration, and by providing a modulated supply of heated dilution air to the gas stream to precisely reduce contaminant concentration levels in the gas stream to a desired percentage of the calculated LEL.

Dependencies are inferred from the claim text.