OCR Text |
Show DISCUSSION The data of Figure 2 exhibit some interesting trends which are summarized below: 1. Even at near stoichiometric conditions, high levels of acetylene (C L) are observed throughout the flame zone. This phenomena has been observed in other chlorinated methane flame mode combustion systems [4, 7], specificially with methyl chloride (CH CI). "Analogous" CH, flames exhibit considerably lower levels of C9H9 (approximately peaking at 400 ppm) as reported in the literature [7]. The increased level of C9H? is significant since C9H? is a known soot precursor. 2. Only trace quantities of ethane (C-H.) were detected in the 2 o CH9C1 system; however, significant quantities of ethene (C9H.) were measured. Analogous CH, flames reported in the literature [7] exhibit higher quantities of both of these compounds. 3. Over the range of 0.22 to 0.26 cm, an abrupt drop in CO is observed with a corresponding rise in C09. By 0.22 cm the fuels have been consumed. Excess 09 is present to 0.3 cm. These conditions suggest the existence of a dual stage combustion process where in the first stage, the fuels are consumed with CO and C0? production and, in the second, CO is futher converted to C0? in the presence of 09. The temperature profile shown in Figure 2 may support this hypothesis. Between 0.22 and 0.26 cm, the data does indeed demonstrate a possible rise in temperature. However, the change is relatively small and may be interpreted as scatter in the data. A solid 5.3.14 |