| OCR Text |
Show TABLE 1. SUBSCALE BURNER TEST RESULTS Heat Release MJ/hr (Btu/hr) Burner A S30 (500,000) Burner B 265 (250,000) Emissions (ppmv) NO, 11 IB CO 4 19 UHC <1 3 Burner Temperature k (°F) 1410 (?OttO) 1240 (1780) Pressure Orop Pa (In. w.g.) 996 (4) 62 (0.2b) Note that the emissions for both burners are low, but the surface temperature and pressure drop through the matrix are yery different for the two burners. The lower temperature of Burner B indicates higher radiant heat transfer and, therefore, potentially higher efficiency or capacity. The efficiency of Burner B is also enhanced by the lower pressure drop, requiring lower blower horsepower. Burner A was also subjected to a cyclical 100-hour life test to investigate emissions and operating characteristics over an extended period. The test was conducted on natural gas at the nominal operating conditions of 800 MJ/hr-m2 (80,000 Btu/hr-ft2) and 10 percent excess air. Figure 2 shows the N0x emissions, which remained at about 12 ppm throughout the test. In addition, no degradation in CO, UHC, burner temperature, or combustion stability occurred. These subscale tests confirmed that the fiber matrix has good potential as a low NO burner for firetube boilers. The next step in the burner development was demonstration in a commercial firetube boiler. FIRETUBE BOILER DEMONSTRATION To show that the fiber burner operates as successfully in full-scale as in subscale, a boiler of approximately twice the physical dimensions and heat input was selected. Both efficiency and emissions were measured for the as-received package boiler and fiber burner retrofit system. The boiler selected was a York-Shipley 25 hp firetube boiler, purchased and installed in the Acurex combustion laboratory. The boiler has three passes, produces steam at low 3-6 |
