• Patent

Plasma furnace disposal of hazardous wastes

A method and apparatus for plasma waste disposal of hazardouswaste material, where the hazardous material is volatilized undervacuum inside a containment chamber to produce a pre-processed gasas input to a plasma furnace including a plasma-forming region inwhich a plasma-forming magnetic field is produced. Thepre-processed gas is passed at low pressure and withoutcircumvention through the plasma-forming region and is directlyenergized to an inductively coupled plasma state such thathazardous waste reactants included in the pre-processed gas arecompletely dissociated in transit through the plasma-formingregion. Preferably, the plasma-forming region is shaped as a vacuumannulus and is dimensioned such that there is no bypass by whichhazardous waste reactants in the pre-processed gas can circumventthe plasma-forming region. The plasma furnace is powered by a highfrequency power supply outputting power at a fundamental frequency.The power supply contains parasitic power dissipation mechanisms toprevent non-fundamental, parasitic frequencies from destabilizingthe fundamental frequency output power. These power loss mechanismsuse either distributed resistance or frequency-selective power-lossdevices to prevent parasitic oscillations from instantaneouslyturning on the high frequency power oscillator at non-fundamentalfrequencies.


Markunas, R., Posthill, J., Hendry, R., & Thomas, R. (2003). IPC No. U.S. Plasma furnace disposal of hazardous wastes. (Patent No. 6552295).