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 modular corona discharge reactor in which individual reactor chambers are arranged vertically and are grouped in serial pairs.

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 (100) for the plasma assisted treatment of effluent gases such as exhaust from internal combustion engines, and effluent gases from industrial processes and incineration. The reactor includes a stage for the plasma-assisted processing of noxious components in the effluent, such as carbonaceous combustion products from internal combustion engines. A diverter valve (119) is provided for bypassing at least that stage should it become blocked, for example by untreated carbonaceous combustion products. In a particular form of the reactor the treatment stages are modular in form.