OCR Text |
Show content of the heat capacity, and to a limited extent the amount of heat which can be extracted from the flame by the flue gas. Gases are drawn from the furnace through a water-cooled probe for continuous analysis. The gases are analyzed for CO and CO2 with non-dispersive infrared analyzer, for NO and N02 with a chemiluminescence analyzer, and for oxygen with an electrochemical analyzer. A suction pyrometer was used to measure the temperatures in the flame and sheathed thermocouples were used to continuously track changes in the lower temperature regions of the furnace. RESULTS The versatile burner was tested in several configuration in the E&RL 10 x 106 Btu/hr furnace. Results from the tests of the premixed configuration are listed in Table 1 and are reported in this paper. Data was taken under the following conditions: premixed flame load 3.9 - 6.6 x 106 Btu/hr pilot flame on and off flue gas O2 1.5 - 9.0% (d) flue gas recirculation 0 - 34% Measurements were made of gas composition (NO, N02, CO, CO2, and 02) and flame temperatures. The adiabatic flame temperature was calculated, the temperature at 37.5 mm from the quarl was measured using a suction pyrometer; other temperatures were measured using sheathed thermocouples. The emissions of NOx decreased with increasing oxygen and/or the amount of flue gas recirculated. Figure 5 shows that without flue gas recirculation, NOx emissions varied 19 ppm at 9 percent O2 and 50 ppm (d, 3% 02) at 2-3 percent oxygen. Addition of flue gas recirculation at a given oxygen concentration reduced the nitrogen oxide further. The 8 WJS1OO5APAO / AFRC-90-25 |