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Show 500 CVJ o S 400 E Q. 300 200 100- A Vane Position 10 SRB • 0.95 'T^^£ ^ <c^-*_ O Vane Position 2 SRB = 1.00 A ur^ ^r^ i ^%^ 1.0 1.20 1.30 Total Stoichiometric Ratio, SRT Figure 7. Directional Flame Burner N0X Emissions as a Function of Total stoichiometry at Two Directional Vane Positions The effect of lowering burner zone stoichiometry (Figure 8) was also investigated at directional vane positions 2 and 10. Burner zone stoichiometry also had a greater effect at vane position 10 than posi tion 2. The lowest NO emissions achieved were 156 ppm at 3% 09 at X c. SRp = 0.76, vane position 2. The effect of downstream staging air location is shown in Figure 9. As the air was moved further downstream, NO emissions were reduced. When air was injected at 23 ft, NO emissions were the same as the unstaged burner. Under all conditions, the flame was 15 to 25 feet long and stand off ranged from 6 in. to 5 ft. With the Directional Flame burner, burner settings affected NO emissions by 40%. Lowering SRR with the Direc- X D tional Flame burner from 0.15 to 0.85 gave NO reductions of 20%. CO emissions at vane position 2 were higher than for any other setting, ranging from 90 to 290 ppm. CO emissions for all the other settings ranged from 40 to 130 ppm. The highest CO emissions were experienced under staged combustion. 10 |