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Show Test Coal As mentioned previously, four coals were used during the burner Subsystem Testing: the illinois #6, Mahoning 7 A, Kentucky #9,. and Ohio #7 coals. A fifth coal was used for the SOx subsystem testing. Figures 6-8 illustrate the NOx, CO, and LOI comparison for the two test burners firing the different coals. The values shown in the graphs correspond to the optimum burner configuration for the DRB-4ZTM and the DRB-XCL ® burners. Figure 6 shows the reduction in NOx achieved by the DRB-4ZTM burner. NOx reductions for the illinois coal range between 20- 25%, for the Mahoning coal between 40-50%, and for the Horizon coal between 50-55%. The Kentucky #9 and the Ohio #7 coal were not fired with the DRB-XCL ® burner, therefore, no comparison can be made for these coals between the DRB-4ZTM and the DRB-XCL ® burners. The test coals ranged in fixed carbon-to-volatile matter ratios from 1.16 to 1.57, as shown in Table 2. It is evident from Figure 6, that the effect of firing the various coals on NOx emission for the DRB-4ZTM burner is relatively flat across the entire range. The effect on the CO emissions is illustrated in Figure 7. The CO emissions while firing the Mahoning coal were greatly increased for the DRB-4Z™ burner, as could be expected due to the significant NOx reduction. However, looking at the Ohio Horizon coal results, although the NOx was significantly reduced with the DRB-4ZTM burner, the CO emissions were not as greatly affected, with the average remaining around 50 ppm. CO emissions for the Kentucky #9 and Ohio #7 coals remained in the same general range as the lllinois #6 and Ohio Horizon coals. Again, it should be noted that the values reported on the graphs are for the optimum burner configurations for that particular test series, firing the various coals. These graphs do not necessarily represent the average values obtained over the wide variety of test configurations. The LOI values, shown in Figure 8 correspond to the CO emissions. The cases where lower CO emissions were obtained, lower LOI values were also measured. LOI data was not collected while firing the Ohio Horizon coal for either test burner. All fly ash samples collected were measured for loss on ignition at 1380°F. A few random samples were also measured for unburned carbon determined by an ASTM method. A comparison between the two measurements showed that the LOI measurements were on the average 7% higher than the UBC measurements. NOx DRB_4ZTM Subsystem Testing Preliminary ResulJs 0.50.--------------------, 0.40 1------- 0.30 Emission (lb/J06 Btu) 0.20 Figure 6 0.10 NlA 0.00 DRB-4Z XCL DRB-4Z XCL DRB-4Z XCL DRB-4Z XCL DRB-4Z XCL IUinois 16 Mahonlnr 1A Ohio Horlr.on Ktntuclcy 19 Ohio 11 Test Burner NO. Emission Comparison to Test Burner Firing Five Test Coals Page -12 |