The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Apr. 22, 2003

Filed:

Dec. 20, 2000
Applicant:
Inventors:

Robert J. Markunas, Chapel Hill, NC (US);

John B. Posthill, Chapel Hill, NC (US);

Robert C. Hendry, Hillsborough, NC (US);

Raymond Thomas, Chapel Hill, NC (US);

Assignee:

Research Triangle Institute, Research Triangle Park, NC (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K 1/000 ;
U.S. Cl.
CPC ...
B23K 1/000 ;
Abstract

A method and apparatus for plasma waste disposal of hazardous waste material, where the hazardous material is volatilized under vacuum inside a containment chamber to produce a pre-processed gas as input to a plasma furnace including a plasma-forming region in which a plasma-forming magnetic field is produced. The pre-processed gas is passed at low pressure and without circumvention through the plasma-forming region and is directly energized to an inductively coupled plasma state such that hazardous waste reactants included in the pre-processed gas are completely dissociated in transit through the plasma-forming region. Preferably, the plasma-forming region is shaped as a vacuum annulus and is dimensioned such that there is no bypass by which hazardous waste reactants in the pre-processed gas can circumvent the plasma-forming region. The plasma furnace is powered by a high frequency power supply outputting power at a fundamental frequency. The power supply contains parasitic power dissipation mechanisms to prevent non-fundamental, parasitic frequencies from destabilizing the fundamental frequency output power. These power loss mechanisms use either distributed resistance or frequency-selective power-loss devices to prevent parasitic oscillations from instantaneously turning on the high frequency power oscillator at non-fundamental frequencies.


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