OCR Text |
Show An oil nozzle manufactured by Danfoss (8 kg/h, 60 0 S) was used to produce a turbulent diffusion flame in the primary combustion stage. The secondary air stream was designed to flow through pipe inserted inside the furnace in upstream direction in order to produce intensive mixing of the unburnt products with the secondary air. rtl:==:::::IPnmaryair 1.3 ~~--SRI A diagram of experimental combustion tests is shown in Figure 1. Analytical methods Exhaust samples were with -drawn from the reactor along the axis with a stainless steel, waterjacketed probe and analyzed using standard continuous instrumentation (chemiluminiscent NO, zirkonium Secondary '-c=~~ : elr Figure 1. Schematic of experimental two stage combustor. oxide sensor O2 , and NDIR CO and CO~ analyser). A water-cooled quartz gas samp11ng probe with a 3.5 mm outer diameter and a 2 mm inner diameter was used to collect gas phase HCN and NH3 species. HCN and NH3 were measured by an ionelectrode method. Since NH3 and HCN are easily absorbed by water, the sampling line was kept in temperatures between lOO°C and 150°C. Fuel characterization The fuels used in this study were as follows: 1 light oil, SAE30 (01) 2 toluene, C6H5CH3 (T) with 4% oil 3 10% nitrotoluene doped toluene (10NT) 4 30% nitrotoluene doped toluene (30NT) 5 50% nitrotoluene doped toluene (50NT) 6 100% nitrotoluene, C6H4CH3N02 (lOON) Table 1 summarized ultimate analysis and heating values for these fuels. Table 1. Fuel analysis according to %wt N and heating value. Fuel no 1 2 3 4 5 6 Symbols 01 T lONT 30NT 50NT lOON % N wt 0.2 0.05 0.99 2.8 5.1 9.5 Ho MJ/kg 41.0 41.5 39.6 37.1 34.2 26.9 STAGED COMBUSTION OF LIQUID FUELS By way of orientation, staged combustion is typically thought of as a two-zone process. These two zones, are often referred to as the main burner zone, and the final burnout zone, and will be referred to as zone 1 and zone 2. SR1, SR2 3 |