In a gas fuel engine, a first air-fuel mixture having a local excess air factor \u03bb not less than 2 is combusted. A network interface unit is operably connected to a plurality of processing entities and associated memory units. A highest point of each vertical elastic plate forms a support point. The media is entrained into the air by a pressure tank 17 which includes a classifier 18 for reclaiming a portion of the media for reuse.