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Show Combustion Ambient Recuperative Regenerative Energy consumption, MJ/kg aluminum (106Btu/t) 3.04 (2.61) 2.43 (2.09) 1.94 (1.67) NOx emissions ppmv @ 3% 02 (g/MJ / lb/106 Btu) 66 (0.034/0.08) 143 (0.074/0.172) 55 (0.029/0.067) NOx, g NOx/kg Al melted (Ib/t Al melted) 0.10 (0.2) 0.18 (0.36) 0.055 (0.11) The regenerative burner system produces the least amount of NOx per ton of molten aluminum". SUMMARY Development work and application successes have demonstrated the power and versatility of the dilute gas combustion LNI/FDI technique in reduction of N O x emissions in high performance combustion systems without sacrifice of efficiency or heating capability of the furnace. Optimization of LNI/FDI burner parameters has been aggressively followed in conjunction with development of a substantial understanding of the application parameters required to match LNI/FDI in-furnace combustion with the fired process. The LNI/FDI technique has been evaluated for several combinations of fuels and oxidant-supply conditions. It has shown to be a powerful N O x inhibitor with all commonly used practical industrial choices. For regenerative burners, where high air preheat capability offers low fuel consumption, LNI/FDI offers striking N O x emission reduction - to the point that such burners are most likely to offer the lowest mass emissions per unit of production of any combustion system type - ambient air, recuperative, or regenerative - in many high production processes. Application of the technique to liquid fuels significantly broadens the available high-performance system options for their users. Extension of LNI/FDI to oxygen and air/oxygen burners also provides high levels of emissions reduction. Ongoing efforts to reduce the size and cost of the LNI/FDI package are making the technology available and cost effective for even more applications. W e believe LNI/FDI to be the most powerful NOx-inhibiting technology available today for high-temperature process furnaces. REFERENCES 1. US Patent 4,945,841, 07/07/1990, Nakamachi et al., Apparatus or Method for Carrying Out Combustion in a Furnace. 2. Shigeta, E., Kanazawa, H., Koizumi, T., & Nagata, T., (1991) Low-NOx Combustion Technique for High-Temperature Furnace, AFRC/JFRC International Conference on Environmental Control of Combustion Processes, Honolulu, Hawaii. 3. Saiki, N., & Koizumi, T., (1994) Application of Low-NOx Combustion Technique for Regenerative System, AFRC/JFRC Pacific Rim International Conference on Environmental Control of Combustion Processes, Maui, Hawaii. 4. Thermcon Ovens B. V. - Private Communication 5. North American Combustion Handbook, Volume II, (1997). 6. Cain, B. E., Robertson, T. F., & Newby, J. N., (1998) Reducing N O X Emissions in High Temperature Furnaces, International Gas Research Conference, San Diego, California. 9 |