The report gives results of an air pollution emissions control study to: characterize the current field population of industrial boilers; identify trends in boiler design; and assess operating problems associated with combustion modification. Statistics were analyzed to describe the field population and recent sales trends for firetube and watertube industrial boilers in the range from 10 million to 500 million Btu/hr. Boiler capacity, design type, mode of direction, primary and secondary fuels, firing method (for coal), industrial classification, and geographic region of the boiler installation were all considered. When combustion modifications are used to control nitrogen oxide emissions from industrial boilers, practical operating problems may arise, namely: fireside corrosion and deposits on boiler tubes; and flame instability, including blow-off, flashback, combustion-driven oscillations, and combustion noise or roar. These problems were assessed and research needs were identified in relation to such combustion modifications as low-excess-air operation, staged combustion, and fluegas recirculation.

"April 1974." "EPA/650-2-74-032." Final.

As a basis for R & D planning directed to the control of air-pollutant emissions, an EPA grant study was undertaken by Battelle-Columbus Laboratories (1) to characterize the current field population of industrial boilers, (2) to identify trends in boiler design, and (3) to assess operating problems associated with acombustion modification. Statistics supplied by the American Boiler Manufacturers Association were analyzed by Battelle to describe the field population and recent sales trends for firetube and watertube industrial boilers in the range from 10 million to 500 million Btu/hr. Aspects considered were boiler capacity, design type, mode of erection, primary and secondary fuels, firing method for coal, plus the industrial classification and geographic region of the boiler installation. When combustion modifications are employed to control nitrogen oxide emissions from industrial boilers, practical operating problems may arise, namely: (1) fireside corosion and deposits on boiler tubes and (2) flame instability--including blow-off, flashback, combustin-driven oscillations, and combustion noise or roat. These problems were assessd, and research needs were identified in relation to such combustion modifications as low-excess-air operation, staged combustion modification, and flue-gas recirculation.