| OCR Text |
Show stoichiometric ratio, primary flame oxygen enrichment, total flow (approximately inversely proportional to residence time), primary flame oxygen and nitrogen flows, adiabatic flame temperature, post primary flame oxygen flow, and post primary flame oxygen partial pressure. Throughout this first set of experiments, the natural gas flow was held constant at 5.66 m3/hr (200 scfh), and the oxygen and air flows to the burner were varied by experimental design to examine six combinations (plus one duplicate) of oxygen and air flows. Figure 2 presents the combinations of air (57.5 to 105.0 m3/hr, 2030 to 3707 scfh) and oxygen (1.13 to 9.74 m3/hr, 40 to 344 scfh) flows that form the second order rotatable pentagonal design (data points denoted by +). Figure 2 also shows that these air and oxygen flows correspond to a range of calculated stoichiometric ratios from 1.3 to 2.4 (Figure 2a), post flame oxygen flows from 3.29 to 16.37 m3/hr (116, to 578 scfh) (Figure 2b), and post ) primary flame oxygen partial pressures from 5.0 to 16.0 percent (Figure 2c). A summary of the final trial matrix including the controlled and derived system variables is presented in Table I. The seven (six plus one duplicate) experiments, described in Figure 2 and Table I, were conducted in the following manner. The desired natural gas, air, and oxygen flows were set, and the kiln was allowed to thermally equilibrate to the new condition for at least 5 hours. Charges were prepared, sealed, and introduced to the kiln at approximately 10 minute intervals. Between 10 and 12 replicate charges were recorded and averaged for subsequent statistical analy~is. Kiln rotation speed, kiln pressure, and burner position were kept constant at 0.5 rpm, -37.4 Pa (-0.15 in. H20), and -0.34 m (-13.5 in.) inside the kiln front wall, respectively. Note that the effect of the kiln alone is being examined. There was neither afterburning nor external heating of the combustion products. We are trying to determine the behavior 7 |
