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Show I 0 10 20 30 40 50 60 70 Excess «1r (percent) Figure 12. Effect of Excess Air Level (0 to 50 Percent) on Baseline Weighted Average CCI4 Destruction at Various Axial Furnace Positions greater destruction at every excess air level. However, it would also tend to decrease the variation of destruction with oxygen concentration, so that gas temperature and residence time would determine the shape of the curves in Figure 12. Furthermore, for simplicity, a single term was selected to describe destruction, rather than separate, additive terms for oxidation and pyrolysis. Distinct oxidative and pyrolytic kinetic constants are not presently available for the waste compounds of interest. The simplified model therefore predicts no destruction at stoichiometric combustion conditions. In practice, local oxygen availability and pyrolysis will produce nonzero destruction. Of the remaining operating parameters, most affect the model's destruction efficiency through their effect on temperature (recall in-flame destruction is ignored). Their ranking in influence on destruction is therefore the same as Table 2. The inputs which influence only gas temperature in the chemical model are: • Fuel heating value • Flame shape • Waterwall emissivity • Refractory conductivity • Soot loading J 1 1 5.5.24 |