OCR Text |
Show LAB RESEARCH SUMMARY: BITUMINOUS COAL Standardized combustion tests were performed by Battelle under laboratory-simulated utility-boiler conditions to determine with certainty the effect of Velino Ventures Carbonex additive (xylene + organoiron) on the performance of flames of high-volatile pulverized bituminous coal. The influence of one concentration of flame-injected Carbonex iron (5 ppm) was evaluated at two levels of excess combustion air (10 and 26 percent) as a function of secondary combustion air swirl (tuned or detuned) and coal particle size (60 or 80 percent minus 200 mesh). The characteristics of neat bituminous coal flames injected with an equal volume of iron-free xylene carrier established baseline performance. The measurable and reproducible results of the evaluation given in the Summary Table yielded the following signiftcant information: • Reducing secondary combustion air swirl and increasing average coal particle size for xylene carrier-injected coal flames: - Decrease NOx emissions, - Increased mass-mean particulate size, - Increased particulate loading, and - Decreased combustion efficiency, with the changes more or less an function of excess air. • Injecting 5 ppm Carbonex iron into the detuned or coarser-sized high-voltage bituminous coal flames: - Increased NOx emissions, Decreased mass-mean particulate size, - Decreased particulate loading, and - Increased combustion efficiency, with the incremental changes almost offsetting those caused by detuning the burner or coarser grinding the coal. • Reducing excess air from 26 to 10 percent in low-swirl or coarsesize coal flames injected with 5 ppm Carbonex iron resulted in a net reduction in NOx of about 25 percent while maintaining combustion efficiency at the 98+ percent level. |