A weakly ionized plasma is generated by continuous high-power microwave win a dielectric cavity positioned in a slow waveguide. Contaminated air under atmospheric pressure is exposed to the plasma within the waveguide cavity for a limited saturation time controlled by inflow at a regulated flow rate. During such limited saturation time, the contaminated air is purified by sequential ionization and recombination under an electron temperature resulting in a microwave discharge plasma dominated by atomic oxygen at a relatively high saturation density level together with atomic nitrogen at a relatively low density level.
A method is provided for purifying gases, particularly gases contaminated by environmentally harmful substances, by way of plasma discharge. The gas to be purified is guided through a thermal plasma, which is generated by electrodeless ignition of a process gas, so that, by way of the thermal plasma, the harmful substances contained in the gas to be purified are converted to environmentally neutral, fully oxidized substances.
A method and apparatus for abating a compound in a substrate processing system's effluent gases. The method of the present invention begins by introducing ozone and the effluent gases into an abatement device's combustion chamber. Energy is then applied to the effluent gas and ozone. The application of energy, such as thermal or radio frequency energy, then causes a reaction in and between the effluent gases and the ozone, thereby rendering the compound inert. The resultant gases produced are then exhausted out of the combustion chamber.
An apparatus for the treatment of perfluorinated and/or hydrofluorocarbon gases, for the purpose of destroying them, is provided. The apparatus includes at least one high-frequency surface-wave exciter which produces surface waves, a waveguide designed to guide the surface waves produced by the at least one wave exciter to at least one hollow dielectric tube for (i) creating, when supplied with a carrier gas an atmospheric-pressure plasma and (ii) for dissociating the molecules of the perfluorinated and/or hydrofluorocarbon gases within the plasma in order to form reactive compounds, and at least one treatment unit for the reactive fluorinated compounds which is arranged on an exit side of a corresponding hollow dielectric tube.
A device (10) for purifying a gas stream (30) made up of a plurality of DBD cells (12a, 12b, 12c) in series and, for each of the DBD cells (12a, 12b, 12c), a power supply (24a, 24b, 24e) for providing alternating current to each DBD cell (12a, 12b, 12e).
Device for exciting a gas comprising a hollow structure forming a waveguide, made of an electrically conductive material, connected to a microwave generator and including a passage for a hollow dielectric tube adapted for flow of the gas to be excited, the hollow structure further including a wave-concentrating region designed to concentrate microwave radiation produced by the generator onto the tube, during operation of the device, for the purpose of producing a surface wave plasma in the gas, at least one electromagnetic screening sleeve made of a conductive material, fastened to the hollow structure and extending along the extension of the passage so as to surround the hollow tube.
