| OCR Text |
Show gradients and quenching distances for low-to-high-Btu gases will not be made as there are extensive data in the literature on these parameters [4-6]. This information will be folded into the analysis of the physical characteristics of syngas flames determined in this study in order to develop a unified description of flame stability and size. As mentioned, the non-adiabatic flat flame burner is a versatile tool for the study of premixed laminar flames [15-17]. Whereas the maximum temperature of an un-quenched or adiabatic flame is a unique function of the state of the unburned gas, the final temperature of a flame burning on a cooled porous metal burner can, within limits, be fixed independent of the properties of the unburned gas. By flowing gas through the burner head at velocities less than the adiabatic burning velocity, one obtains a maximum flame temperature that is lower than the adiabatic flame temperature. A linear relationship exists between the mass burning velocity and the maximum flame temperature [15]. This trend is illustrated in Figure 1. To obtain the adiabatic burning velocity of a gas mixture, one extrapolates mass burning velocities to the calculated adiabatic flame temperature. This procedure will provide an independent check of the adiabatic burning velocities determined on non-quenched burners [5,6]. Comparisons have generally been agreeable for a wide variety of gaseous flame systems [15]. Once gathered, temperature profiles and burning velocities will be compared to those obtained for single [15] and binary [6] fueled flames. Synthesis gases from coal have CH,, H , and CO as their major combustible constituents; nitrogen, carbon dioxide, and water are the typical diluents. Information will be sought on how the addition of secondary and/or teriary fuel component affects the burning velocity, the maximum flame temperature, and the characteristics of the temperature profile through the flame front. This knowledge, when assembled with other syngas flame physical data [4-6], should permit the development of empirical relations that may be useful in predicting the physical characteristics of syngas flames over a wide range of fuel chemical compositions, availabilities of oxidant, and fuel/diluent ratios. This information should help to anticipate and solve future |
