Flame hydrogen-oxygen-nitrogen

Bregeon B., Gordon A.S., and Williams F.H., Near-limit downward propagation of hydrogen and methane flames in oxygen-nitrogen mixtures. Combust. Flame, 33 33-45,1978. 

Thompson, J.D. and Enloe, J.D., Flammability limits of hydrogen-oxygen-nitrogen mixtures, Combust. Flame, 10, 393,1966. 

Warnatz, J. 1981. Concentration-, pressure-, and temperature-dependence of the flame velocity in hydrogen-oxygen-nitrogen mixtures. Combustion Science Technology 26 203-14. 

R.F. Heinemann, K.A. Overholser, and G.W. Reddien. Multiplicity and Stability of the Hydrogen-Oxygen-Nitrogen Flame The Influence of Chemical Pathways and Kinetics on Transitions between Steady States. AIChE J., 4 725-734,1980. 

In the following we present an application of laser induced fluorescence to a study of the chemistry of sulfur in rich hydrogen/oxygen/nitrogen (H2/O2/N2) flames and demonstrate a simple rationale for taking quench effects into account. Fluorescence measurements for S2, SH, S02, SO, and OH along with measurements of flame temperature and H-atom (in sulfur free flames) have been employed to develop a kinetic model for the highly coupled flame chemistry of sulfur. The kinetic aspects of the study already have been presented in considerable detail (6). 

Jensen and Padley (1 ) determined an equilibrium constant for the reaction Cs(g) + H20(g) CsOH(g) + H(g) at 2475 K by atomic absorption spectroscopy in a hydrogen-oxygen-nitrogen flame. These workers pointed out that interference from ionization of the metal had introduced some uncertainty in their equilibrium data. Using all JANAF functions (2), 3rd law analysis of the equilibrium constant gives A H (298.15 K) = 27.4 kcal mol". This leads to an enthalpy of formation,... 

Jenkins (2) investigated the same equilibrium in a fuel-rich hydrogen-oxygen-nitrogen flame and eliminated the ionization problem by working at a lower temperature (1570 K). 3rd law analysis of their equilibrium data gives A H (298.15 K) 28.9 kcal mol" which results in A H (CsOH, g, 298.15 K) = -62.7i2.0 kcal mol" corresponding to Dq (Cs-OH) = 89.6 kcal raol". ... 

The bond dissociation energies of the alkali metal hydroxides have been the subject of a number of investigations (1[ -4) in recent years. The majority of this work has involved equilibrium studies on the reaction A(g) + HpO(g) = AOH(g) + H(g), where A is an alkali metal, in hydrogen-oxygen-nitrogen flames containing water. In the case of NaOH, data are summarized below ... 

Schofield ( ) considered the dihydroxide to be the dominant product and derived Dq = 215 12 kcal mol . Cotton and Jenkins (3) found both SrOH and Sr(0H)2 to be present in significant amounts in fuel-rich hydrogen-oxygen-nitrogen flames and derived D = 202.2 5 kcal mol Cotton and Jenkins ( ) recalculated the work of Ryabova and Gurvich (1 ) and of Sugden and Schofield ( )... 

Mitani, T. and Williams, F. (1980) Studies of cellular flames in hydrogen-oxygen-nitrogen mixtures. Combustion and Flame, 39 (2), 169-190. 

B. Bregeon, et al., "Near-Limit Downward Propagation of Hydrogen and Methane Flames in Oxygen-Nitrogen Mixtures," Comb. Flame, 33 33-45, 1978. 

G. Dixon-Lewis, Kinetic mechanism, structure and properties of premixed flames in hydrogen-oxygen-nitrogen mixtures. Phil. Trans. R. Soc. London A292(1388), 45-99 (1979)... 

The composite flux method with quasi-steady-state assumptions has been used in studies of hydrogen-oxygen-nitrogen flames (Dixon-Lewis, 1979a) and of a hydrogen-air flame inhibited by hydrogen bromide (Dixon-Lewis, 1979b). However, the same order of accuracy is now obtainable by the finite-element technique described in Section 6.2. 

Let us reconsider the critical flame temperature criterion for extinction. Williams [25], in a review of flame extinction, reports the theoretical adiabatic flame temperatures for different fuels in counter-flow diffusion flame experiments. These temperatures decreased with the strain rate (ua0/x), and ranged from 1700 to 2300 K. However, experimental measured temperatures in the literature tended to be much lower (e.g. Williams [25] reports 1650 K for methane, 1880 K for iso-octane and 1500 K for methylmethracrylate and heptane). He concludes that 1500 50 K can represent an approximate extinction temperature for many carbon-hydrogen-oxygen fuels burning in oxygen-nitrogen mixtures without chemical inhibitors . 

Compounds are burnt in the flame producing ions and thus an increase in current between the jet and the collector. Detects carbon/hydrogen-containing compounds. Insensitive to carbon atoms attached to oxygen, nitrogen or chlorine. In combination with capillary GC it may detect as low as 100 pg-10 ng. Wide range of linear response ca 10 ... 

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