Evaporative desorption soil treatment apparatus and process

Abstract

Treatment apparatus and a process for thermal desorption of hydrocarbon contaminants from excavated soil provides efficient contaminant removal by handling the soil in a thermally conductive treatment vessel that fits within an insulated treatment chamber. The soil is treated in this chamber with fresh air that is dried and electrically heated prior to contacting the treatment vessel. Excavating the soil directly into the treatment vessel allows the treated soil to be returned to the final disposition site in the same vessel, minimizing soil handling

Description

[0001] This application claims priority from Provisional Patent Application 60 / 354,572, "Evaporative Desorption Soil Treatment Apparatus and Process" filed on Feb. 06, 2002.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0002] Not Applicable.REFERENCE TO A MICROFICHE APPENDIX[0003] Not Applicable.BACKGROUND OF THE INVENTION--FIELD OF THE INVENTION[0004] This invention relates to a process and apparatus for thermal desorption of contaminates from a mixture of soil and rocks using desiccated, electrically-heated fresh air to treat the soil and rocks which have been excavated and placed in a thermally conductive treatment container which is then placed in a thermally insulated treatment chamber. The fresh, hot, desiccated air is drawn through the soil treatment container, cooled, and released; or discharged to a treatment system, as required or needed, prior to release to the atmosphere.BACKGROUND OF THE INVENTION--DESCRIPTON OF RELATED ART[0005] The use of petroleum h...

AI Technical Summary

Benefits of technology

[0030] A third object of this invention is to use dry air as the treatment gas. This increases the efficiency of heat delivery by eliminating the latent heat of vaporization of entrained moisture and improves the efficiency of hydrocarbon and water removal from the treated soil.

[0031] A fourth object of this invention is to provide efficient heat transfer to the soil. This reduces the energy required to treat a batch of soil.

[0033] A sixth object of this invention is to provide a soil treatment container in which the soil may be inserted into as it is excavated, and therefore does not require further handling of the soil until treatment is complete and it is being placed in returned to its final disposition location.

Problems solved by technology

One risk associated with the storage and handling of petroleum hydrocarbons is the potential for spillages, during handling or the potential for leakage during storage.

This has the undesirable consequence of forming products of incomplete combustion, oxides of nitrogen, and other greenhouse gases as a by-product.

Combustion also has the potential to add unburned hydrocarbons to the process exhaust gas if strict control of the combustion process is not maintained.

The pile arrangement processes do not require energy-intensive material handling during treatment, however they may be characterized as requiring labor-intensive setup and disassembly in the activity of layering the piping system within the soil pile and removing it following treatment, and also in covering and uncovering the completed pile.

A disadvantage of these prior-art container arrangements is they require handling the soil to move it from the container in which it was placed after excavation, which presumably would be a dump truck hopper, load it into the treatment container for treatment, and then handle it again following treatment to put it back into the dump truck hopper for disposition.

This reduces the energy required to treat a batch of soil.

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