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Show - 11 - formation for this burner becomes significant when the hydrocarbon concentration falls below 30% (Le. 70 mole% hydrogen). CONCLUSIONS The development work successfully resulted in a burner that produced a flat, radial flame pattern when firing a variety of fuels from natural gas to 100% hydrogen. The burner produced NOx emissions well below the requirements of the initial application for all of the hydrogen/natural gas mixtures with 350 OF air preheat. NOx emissions, expressed as pounds of NOx per million Btu fired, were lower for fuel mixtures with very high hydrogen concentrations. This has been attributed to a reduction in the amount of NOx generated by the prompt NOx mechanism for these mixtures. REFERENCES 1. Waibel, R. T.: Ultra Low NOx Burners for Industrial Process Heaters, Second International Conference on Combustion Technologies for a Clean Environment, Lisbon, (1993) 2. Miller, J. A. and Bowman, C. T.: Prog. Energy Combustion Science, Vol. 15, pp. 287 -338 (1989) Copyright 1994 John Zink Company, a division of Koch Engineering Company, Inc. All rights reserved. |