OCR Text |
Show 1.3.19 the flame which was not carried out in this study. As the fuel-bound sulfur content is practically same in both No. 2 oil and SRC-II oil, there is no significant difference in the peak value of S02 concentration in the product gases at the end of their flames. The increase of S02 concentration in the No. 2 oil flame caused by emulsification can be probably attributed to the increase of hydroxyl radicals which promote the oxidation of sulfur and SO to S0? [20]. The insignificant change in S02 concentration in SRC-II oil flame is likely the consequence of higher 02 concentration in the far-nozzle region evidenced in Figure 3, which promotes the formation of S0~ and this masks the increase of S02 concentration [21]. CONCLUSIONS This comparative study of the temperature and concentrations of 02, NO, CO, and S02, in the gases at the end of the visible flames of air-blast atomized sprays of No. 2 oil (petroleum based), SRC-II oil (coal derived), and their unstabilized emulsions with 5 percent of water has shown the following: (i) oxygen utilization, which is a measure of combustion efficiency, is lower in SRC-II oil flame than in No. 2 oil flame, (ii) the emission of CO is lower and NO is higher from SRC-II oil flame than from No. 2 oil flame, but the S02 emission is approximately same from the flames of both fuels, (iii) the emulsification with water decreases CO emission from the flames of both No. 2 oil and SRC-II oil, and (iv) the emulsification with water slightly increases NO and S0? emission from No. 2 oil flames, and it does not change them significantly in SRC-II oil flames. These effects are explained by the differences in the flame structure of No. 2 and SRC-II oils and the changes |