High power self-shielded electron processors and their application to stack gas treatment

The increasing industrial demands for large width (approximately 2 m), high dose rate (1 megarad at 1500 meters/minute) electron beam machinery has led to a relatively rapid improvement in this field over the past several years. Selfshielded machinery capable of up to 1000 mA of current at 300 kilovolts is now in commercial use, and the essential features of these designs are presented. A variety of product handling geometries for use with these accelerators have been developed, for processes involving flexible web, rigid sheet, and three dimensional objects in both the polymerization and sterilization applications. One of the major power intensive processes to which these machines are currently applied is that of the reduction of pollutants (NOx, SO2, etc.) in the flue gas from fuel combustion - particularly those fossil fuels used in power production. The preferred technique utilizes the treatment of the ammoniated gas at modest dose levels (0.5 - 2.0 megarads) to enhance the formation of ammonium salts which are then removed from the gas stream by conventional filtration. Some results from a 180 kW x 300 kV pilot installation in Karlsruhe, West Germany, are presented. (author)