Abstract: A microwave plasma generator including field-enhancing electrodes consisting of opposed laminae (108,109) with a gap (110) between them orthogonal to the direction of propagation through the plasma generator of microwave radiation. Gas inlet (106) and outlet (107) ports are arranged so that a gaseous medium to be excited into the plasma state passes through the gap (110).

Abstract: A reactor chamber forms part of an exhaust system of an internal combustion engine. Within the chamber are electrodes between which there is disposed a bed of active material through which, in use, the exhaust gases pass. In the presence of an electrical discharge, driven by an electrical voltage applied across the electrodes, the active material has a catalytic action in the reduction of nitrogenous oxides in the exhaust and also acts to remove hydrocarbons from the exhaust gases.

Abstract: A reactor (1) particularly for the plasma treatment of internal combustion engine exhaust gases, in which a power supply (10) and a reactor bed (2) of the dielectric barrier discharge type are connected directly and enclosed in an earthed metal chamber (17) which both isolates the high voltage power supply and acts as a Faraday cage preventing the emission of electromagnetic radiation from the power supply or plasma.

Abstract: A reaction chamber (12, 49) is adapted to be coupled to a source of microwave radiation. A pair of opposed field enhancing electrodes (18, 21; 62, 63) concentrate microwave energy so as to form plasma in a localised region between the electrodes. Gas passages are arranged for passing a gaseous medium into and out of the chamber so that the gaseous medium passes through the said localised region of plasma. The electrodes comprise electrically conducting tubes (18, 21; 62, 63) held in electrode holders (17, 19; 53, 54) located in the chamber wall, the electrode tubes being removable and replaceable from outside of the apparatus.

Abstract: A microwave plasma generator including field-enhancing electrodes consisting of opposed laminae (108,109) with a gap (110) between them orthogonal to the direction of propagation through the plasma generator of microwave radiation. Gas inlet (106) and outlet (107) ports are arranged so that a gaseous medium to be excited into the plasma state passes through the gap (110).

Abstract: A reactor chamber forms part of an exhaust system of an internal combustion engine. Within the chamber are electrodes between which there is disposed a bed of active material through which, in use, the exhaust gases pass. In the presence of an electrical discharge, driven by an electrical voltage applied across the electrodes, the active material has a catalytic action in the reduction of nitrogenous oxides in the exhaust and also acts to remove hydrocarbons from the exhaust gases.

Abstract: The space between parallel electrode plates (12, 13) of the reactor is dimensioned to make it possible to produce plasma at reasonable applied potential within the gas passages (15) of a monolithic substrate, such as a wallflow filter, in a slice (11) positioned between the electrode plates (12, 13).

Abstract: Hydrogen is generated from hydrocarbon fuel by a reforming reaction in a reactor (11) in which gaseous hydrocarbon and reforming reaction agents are subjected to the formation of a plasma having an electric field strength within the plasma exceeding 10,000 volts per centimetre, preferably at least 20,000 volts/cm, more preferably at least 40,000 volts/cm or even 80,000 volts/cm. The apparatus has electrodes (14, 15, 16) and dielectric material (22-27), the configuration of which allows for plasma having the electric field strength defined above.

Abstract: A reactor (100) for the plasma assisted processing of a gaseous medium, including a cylindrical bed (106) of active material (107) contained between two concentric electrodes (108, 109), both of which are earthed and with a third cylindrical electrode (111) concentric with the other electrodes positioned within the bed of active material (107) and connected to a high voltage input terminal (112).

Abstract: A reactor for the plasma-assisted processing of gaseous media comprising a reactor chamber including a gas permeable bed of active material, a power source for applying across the bed of active material a potential sufficient to establish a plasma in a gaseous medium flowing through the bed of active material and a chamber having an inlet stub and an outlet stub for constraining the gaseous medium to flow through the bed of active material, wherein the bed of active material comprises a matrix of beads of a dielectric material having an assembly of regular arrays of beads in each of which adjacent beads are connected to a high voltage input terminal or an electrical ground.

Abstract: A reactor for the plasma processing of gaseous media, especially internal combustion engine exhaust, has a bed made of a body of ceramic material a series of gas permeable electrodes embedded within the bed. The electrodes are distributed to provide a predetermined electric field distribution within the bed.

Abstract: A reaction chamber (12, 49) is adapted to be coupled to a source of microwave radiation. A pair of opposed field enhancing electrodes (18, 21; 62, 63) concentrate microwave energy so as to form plasma in a localised region between the electrodes. Gas passages are arranged for passing a gaseous medium into and out of the chamber so that the gaseous medium passes through the said localised region of plasma. The electrodes comprise electrically conducting tubes (18, 21; 62, 63) held in electrode holders (17, 19; 53, 54) located in the chamber wall, the electrode tubes being removable and replaceable from outside of the apparatus.

Abstract: A reactor for the plasma assisted processing of gaseous media, including a cylindrical reactor bed of gas permeable dielectric material contained between two co-axial electrodes, wherein the inner electrode has associated with it a number of radially projecting vanes or disks made of a dielectric material having a permittivity greater than that of the reactor bed material.

Abstract: A reactor for non-thermal plasma assisted treatment of a gaseous medium incorporates at least one electrically conducting mesh filter element positioned so that gaseous medium passes therethrough. At least one dielectric barrier layer provides for a dielectric barrier type discharge, when an electrical power supply is connected to the electrodes to generate the plasma.

Abstract: A reactor particularly for the plasma treatment of internal combustion engine exhaust gases, in which a power supply and reactor bed are connected directly and enclosed in an earthed metal chamber which both isolates the high voltage power supply and acts as a Faraday cage preventing the emission of electromagnetic radiation from the power supply or plasma.

Abstract: A reactor for the plasma processing of gaseous media, especially internal combustion engine exhaust, has a bed made of a body of ceramic material and electrodes. At least one electrode terminates within the bed at a distance from earthed supporting structure to avoid or reduce the risk of tracking or arcing between the electrode and the supporting structure.

Abstract: A reactor for the plasma processing of gaseous media, especially internal combustion engine exhaust, has a bed made of a body of ceramic material and electrodes. At least one electrode terminates within the bed at a distance from earthed supporting structure to avoid or reduce the risk of tracking or arcing between the electrode and the supporting structure.

Abstract: A plasma enhanced gas reactor including a reaction chamber having a pair of field-enhancing electrodes each of which has an axial passage through it by one of which a reactant gas is admitted to the reaction chamber, and by the other of which reaction products are removed from the reaction chamber.

Abstract: An apparatus for detecting the presence of volatile substances in a gaseous medium, including apparatus for producing within a sensor chamber a localised electric field the energy density of which is sufficient to excite the gaseous medium to a plasma condition, and apparatus for detecting changes in a parameter of the plasma due to the presence of the volatile substances in the gaseous medium.