| OCR Text |
Show extremely low oxidant levels. Traditional burner systems are extinguished by these high recirculation rates. An LNI combustion system is designed to take advantage of the dilution to provide ultra low N Ox emission levels. Equilibrium NOx Production vs. Oxygen Concentration and Temperature 12000 10000 E g 8000 •| 6000 (A E w 4000 o- 25 20 15 10 5 0 Oxygen Level, % Figure 2 LNI Combustion Systems An LNI burner operates as a high velocity nozzle mixing burner when the furnace temperature is below 1400 F. Above 1400 F, fuel is switched to strategically positioned nozzles adjacent to the burner tile port. These injectors are displaced from the burner tile exit inside the furnace [Figure 3]. Fuel and oxidant streams mix thoroughly with furnace gases, becoming extremely dilute before combining in front of the burner tile. Oxygen concentrations can be lowered to below 5 % in the oxidant stream. The dilute gas streams autoignite and achieve complete combustion within the furnace environment. In the flame envelope, entrained gases limit maximum in-flame combustion temperatures that generate high N Ox emissions. 4 |
