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Show ~~--------------------------------, 50 -'i!. (')40 ~ E D. D. -830 )( 0 c CD Cl g20 Z 10 0 8 o 3.9 x 108etu/hr, No FGR o 3.9 x 108etu/hr, No FGR 6. 4.4 X 108etu/hr, No FGR ~ 6.6 X 10 8etu/hr, No FGR O~--~--~--~--~--~--~----~~ 1,200 1,300 1,400 1,500 1,600 1,700 1,800 1,900 2,000 Temperature rC) WJS1005D.DRO Figure 8 Comparison of Estimated and Measured NOx Emissions. COMPARISON Levels of NOx were estimated as functions of flame temperatures (Figure 8) to design the versatile burner (5,6). Figure 7 shows a comparison between the measured NOx emission, at the calculated adiabatic flame temperature, two seconds residence time, and 2 percent oxygen in the flue gas. The measured emissions of NOx show a minimum value of 12 ppm (d, 3% 02) an increase as the adiabatic flame temperatures increases (oxygen decreases), a peak of 50 ppm (d, 3% 02) at 1750°C, and a decrease above 1800°C. The peak and decrease in NOx emissions are thought to be caused by the effect of the decrease in oxygen necessary to reach high temperatures on the NOx formation kinetics. The estimated NOx emissions show less than 1 ppm NOx at 1300°C and a rapid increase of NOx emissions above 1650°C. 15 WJSlOOSAPAOjAFRC90-25 |