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Show meeting the NOx emission goal of 0.1 lb NO/MBtu. The MIT -RSFC was an experimental pilot-scale burner. The B&W DRB-XCL ® was a commercial burner that had been scaled down to pilot level. The pilot-scale DRB-XCL ® burner had been extensively tested in B&W's Small Boiler Simulator (SBSi, and testing had been performed with the commercial scale DRB-XCL ® burner. The testing of the DRBXCL ® in the CRF allowed for a comparison between the MIT combustion test furnace and a vertical furnace shaft as in the B&W SBS and typical commercial boilers. A single MIT -RSFC burner was tested. However, through spin vane adjustments and air flow changes, two very different flames were produced. These configurations were referred to as RSFC-A and RSFCB. As an un staged burner, RSFC-B was characteristic of a 10w-NOx burner, and was similar in emission performance to the DRB-XCL ®. NOx emission levels, at a stoichiometry of 1.15, were between 230 to 290 ppm. As an unstaged burner, the RSFC-A had a very high NOx emission of between 800 to 1000 ppm. The staging results did not follow conventional NOx reduction approaches. The RSFC-A, which had the high NOx unstaged characteristic, gave the lowest NOx emissions with levels below 100 ppm at a stoichiometry of 0.9. The RSFC-B could not reach near these levels. Two pilot-scale DRB-XCL ® burners were tested. The first burner was designed for unstaged burner testing (Unstaged DRB-XCL ®), while the second burner was designed to have the same air flow velocity when staged to a 0.85 stoichiometry (Staged DRB-XCL ®). Tests were also performed with the DRBXCL ® burner in which the flame stabilizing ring and air separation plate were removed, and an impeller was added (Modified DRB-XCL ®). This was done to try to mimic the performance of the RSFC-A. The Unstaged DRB-XCL ® burner gave NOx emissions similar to those found with the RSFC-B of 230 to 290 ppm. These values were higher than what has been seen in previous pilot-scale testing in B&W's SBS with similar coals. The Staged DRB-XCL ® burner, operating in an unstaged mode, resulted in NOx emission values around 295 to 310 ppm (again higher than previous testing). When staged to a stoichiometry of 0.9, the Staged DRB-XCL ®, gave NOx emissions of 270 ppm. At a stoichiometry of 0.74, the Staged DRB-XCL ® gave NOx emissions of 148 ppm. Since, these values were not near the low NOx emission values obtained with the RSFC-A, the DRB-XCL ® burner was modified as mentioned above. The Modified (atypical) DRB-XCL ® burner, unstaged, gave NOx emissions of 900 to 1000 ppm, similar to the RSFC-A unstaged. When staged to a stoichiometry of 0.85 to 0.75, the NOx emissions were found to be 240 to 250 ppm. The Modified DRB-XCL ® could not obtain the low NOx emissions as the RSFC-A did. 7 |