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Show FUEL ANALYSIS The primary fuels used in this study consisted of No. 2 fuel oil, lignite, and high rank coals from Indiana, West Virginia and Pennsylvania The laboratory analysis of these fuels is presented in Tables 1 and 2. Of particular interest is to note the range of moisture content, volatile matter, fixed carbon and gross calorific heating values which are spanned by the parent coals. A wide range of coals is covered with the selection of these coals used in this study. All mixtures were tested at the 50 weight percent coal loading. The Indiana parent coal was sized at 15pm. The West Virginia parent coal was sized at both 15pm and 44pm. The Pennsylvania parent coal was sized at 15pm. The North Dakota lignite was 100 percent passing through a 200 U.S. standard sieve mesh (=74pm). Accordingly, the North Dakota lignite is classified as pulverized coal while the other three coals (Indiana, West Virginia, and Pennsylvania) are classified as micronized coals. Table 3 presents the viscosities of the various No. 2 fuel oil-coal mixtures that were tested. All data was obtained on a Brookfield, constant shear rate viscosimeter. The data was obtained at a shear rate of 1.0s and at a mixture temperature of 25°C (77°F). All mixtures were fired without fuel preheat at temperatures near 25°C (77°F). It should be noted that further viscosity tests indicated a pseudoplastic behavior of the fuel mixtures evidenced by a decrease in viscosity as shear rate increased. RESULTS OF PREVIOUS STUDIES A mixture of No. 2 fuel oil and lignite was investigated by the authors prior to the current concentrated study (5). This previous study was conducted using the low pressure air atomizing burner (Eclipse Model 168-HCF-CGO) previously discussed. Considerable difficulties were encountered not only with the burnei itself, hut also the pumping system used. The results of this study Indicated th.it .i maximum oi 20 weight percent lignite could be mixed with No. 2 fuel oil resulting in a stable, compact flame similar to the No. 2 fuel oil flame. Beyond 20 weight percent, the flame became unstable with improper atomization manifested by large unburned slugs falling to the chamber floor. Clearly, loadings 7 |