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Show 2,000 r-----------------..... 8 ..d 6.6 x 10 Btu/hr, 2.5% 02'51.6 ppm NOx o 3.9 x 106 Btu/hr, 3.6% 02'43.9 ppm NOx 1,500 o 3.9 x 106 Btu/hr, 9.0% 02'18.0 ppm NOx 6 t...- .C.D ::J a.s. 1,000 CD Do E .C.D. 500 oo~ -~100- --200- --300~ --400~ -~50-0 -~60 0 Distance from Quarl (cm) WJS1005C.DAO Figure 7 Flame Temperature Profile. Regardless of whether the temperature is reduced using air or flue gas, the ultimate NOx emissions seems to be the same, 12 ppm. Confirming that NOx emissions at this level is insensitive to temperature. The temperature profiles decrease rapidly near the quarl slowly in the remainder of the furnace, and the exit temperatures (fraction of heat extraction (46-53) are nearly the same regardless of flame conditions. Temperature profiles for example loads are shown in Figure 7. Other features of the flames were briefly investigated. The pilot flame alone produced 7 ppm. However, the NOx emissions decreased less than 2 ppm (10 percent) when the pilot flame was shut off from an operating premixed flame. The level of N02 were not significant. The NOx emissions changed little with load. 14 WJSlOOSA.PAOj AFRC-90-25 |