Patent ID: 7618215

Claim:
A method for cleaning a soil containing contaminants comprising the steps of: introducing at least one heat-conductive pipe in said soil, whereby said pipe is in working condition under negative pressure and comprises a perforated outer pipe which is provided with a non perforated inner pipe of a smaller diameter such that a space is created between the inner and the outer pipe, heating said soil by thermal conduction by circulating a heated fluid through said heat-conductive pipe and temporarily reversing the flow of said heated fluid through the pipe, thereby obtaining a contaminant vapor, whereby said contaminant vapor is forced into the heat-conductive pipe through a negative pressure present herein, further transporting said contaminant vapor in said heat-conductive pipe out of the soil, incinerating said contaminant vapor in order to at least partly remove said soil contaminants, and re-using the heat energy obtained by incinerating said contaminant vapor for heating said soil in order to vaporize the remaining contaminants in said soil.