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Show . ) 'r was preheated were controlled to 120°F at the burner inlet, while the secondary (combustIon at t'on pass . b the convec I to 620°F. Stack gases were sampled continuously from a locatIon. a ove 0 SO and section outlet through a heated sample line, After filtering and drymg, CO, CO2' F2' ~ exit NOx concentrations were measured and plotted on a Chessell strip chart recorder. u~ac N ngas temperatures were measured by a K-type, high-ve!ocity-thennocouple (HVT) pro;, 0 d intrusive flame temperature mapping was done with an optical pyrometry system from ~amo; d Power Specialty Company called FLAMEVlEWTM. The unit was comprised of a Charge oup .e Device (CCD) array camera mounted on the roof of the SBS and directly above the fl.ame wIth a 50° field of view. Two dimensional temperature maps were generated from the bve flame image via a patented process utilizing two-color pyrometry. Stack fly ash was s~pled isokinetically using a B&W SLM sampling probe. Cumulative batch samples were obtruned by radial traverses and analyzed for carbon utilization. Baseline Testing. Benchmark tests with B&W's pilot-scale B&W DRB-XCL® burner were initially performed to set a comparison for the LEBS burner. The pilot-scale DRB-XCL ® has previously been tested in the SBS facility with different coals[3], and extensive field data on the commercial scale DRB-XCL ® PC burner[ 4] was available for comparison. Benchmark testing was perfonned in the SBS with the lliinois #6 LEBS design coal. Operating conditions at various loads and excess air levels were documented. Furnace exit gas temperatures, FLAMEVIEW temperature mappings, and fly ash samples were taken for various furnace conditions. Parametric Testing. Pilot-scale testing of the LEBS advanced 10w-NOx burner included variations to the air distribution, primary and secondary swirl, coal delivery, excess air, load, primary air-to-secondary air ratio, and burner stoichiometry[5]. NOx emissions for the advanced 10w-NOx burner configurations were found to be lower than with the baseline DRB-XCL ® burner, while CO and DBC values remained consistent. Figure 2 shows the comparison between NOx emission.s and unstaged burner configurations tested at the pilot -scale level. Tests were performed staging the burner from 1.16 to 0.85 burner stoichiometry (BSR). Due to fan limitations, the burner could not be staged any deeper. The preliminary results indicated approximately a 35% reduction in NOx emissions when comparing the unstaged results (BSR=I.16) to the staged results at 0.85 burner stoichiometry, which corresponds to typical field experience. %NOx Reduction Compared to 1 I-,--~----+-----I DRB-XCL Figure 2 NO. Emissions of the Pilot-Scale Unstaged DRBXCL ® Burner in Comparison to the LEBS Unstaged Advanced Low-NO. Burner Configurations Page - 5 |