An apparatus having a first and second zones, for destroying hazardous compounds of a first and second types respectively present in a gas stream. The first zone has a first live electrode and a ground electrode. The first live electrode and the ground electrode define a first gas passage. These electrodes are excitable at a first energy level for generating a first electric field capable of generating a plasma in a gas flowing through the first gas passage. The second zone has a second live electrode spaced apart from the ground electrode. The second live electrode defines with the ground electrode a second gas passage communication with a downstream end of the first gas passage. The second live electrode is excitable at a second energy level for generating with the ground electrode a second electric field capable of sustaining the plasma in the gas flowing through the second gas passage. The second live electrode is located within electrically excitable distance from the first live electrode, whereby when the first energy level is different from the second energy level, either in their respective voltages, phases or frequencies, a third electric field is generated between the first and second live electrodes. This third electric field provides an additional source of energy between the first and second electric fields for sustaining the plasma throughout both zones, and for preventing a backward recombination of the hazardous compounds of the first type leaving the first zone.
A substrate is configured with first and second sets of electrodes, where the second set of electrodes is positioned asymmetrically between the first set of electrodes. When a RF voltage is applied to the electrodes sufficient to generate a discharge plasma (e.g., a one-atmosphere uniform glow discharge plasma) in the gas adjacent to the substrate, the asymmetry in the electrode configuration results in force being applied to the active species in the plasma and in turn to the neutral background gas. Depending on the relative orientation of the electrodes to the gas, the present invention can be used to accelerate or decelerate the gas. The present invention has many potential applications, including increasing or decreasing aerodynamic drag or turbulence, and controlling the flow of active and/or neutral species for such uses as flow separation, altering heat flow, plasma cleaning, sterilization, deposition, etching, or alteration in wettability, printability, and/or adhesion.
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.
An OAUGD plasma is generated using, for example, paraelectric or peristaltic electrohydrodynamic (EHD) techniques, in the plasma generator of a remote-exposure reactor, wherein one or more active species, especially oxidizing species in the plasma are convected away from the plasma-generation region and directed towards a workpiece that is located outside of the plasma-generation region (e.g., within an optional remote-exposure chamber configured to the plasma generator). In this way, the workpiece can be subjected to the one or more active species without directly being subjected to either the plasma or to the electric fields used to generate the plasma. The plasma generator may have a set of flat panels arranged within an air baffle to convect the active species in a serpentine manner through the plasma generator. The remote-exposure reactor can also be configured as a portable backpack unit with tubing that is used to direct the active species onto the workpiece, rather than placing the workpiece within a remote-exposure chamber of the reactor.
An OAUGD plasma is generated using, for example, paraelectric or peristaltic electrohydrodynamic (EHD) techniques, in the plasma generator of a remote-exposure reactor, wherein one or more active species, especially oxidizing species in the plasma are convected away from the plasma-generation region and directed towards a workpiece that is located outside of the plasma-generation region (e.g., within an optional remote-exposure chamber configured to the plasma generator). In this way, the workpiece can be subjected to the one or more active species without directly being subjected to either the plasma or to the electric fields used to generate the plasma. The plasma generator may have a set of flat panels arranged within an air baffle to convect the active species in a serpentine manner through the plasma generator. The remote-exposure reactor can also be configured as a portable backpack unit with tubing that is used to direct the active species onto the workpiece, rather than placing the workpiece within a remote-exposure chamber of the reactor.
A method and apparatus for treating a work surface, wherein there is provided a chamber having a longitudinal axis and longitudinally extending electrically conductive sidewalls, at least one sidewall having at least one longitudinally extending gap that interrupts a current path through the sidewalls transverse to the longitudinal axis, and wherein the chamber is sealed to allow pressure inside the chamber to be controlled. Also provided is an axially-extending array of current-carrying conductors which at least partially encircle the chamber, are transverse to the longitudinal axis, and establish a magnetic field parallel to the longitudinal axis of the chamber, and a power supply connected to the conductor array and adapted to provide high-frequency current in the conductors to magnetically induce ionization of the gaseous material in the chamber and form a plasma sheath that surrounds and extends along the longitudinal axis and conforms to the sidewalls of the chamber, and wherein the work surface is exposed to the plasma sheath and extends in the direction of the longitudinal axis.
