Photümetric Measurements on the Deviations from the Equilibrium State in Burnt Fiame Gases

Photometric investigations are reported in laminar, preaixed shielded flames above the reaction zone, burning at atmospheric pressure. In these CO/Ng/Og -, CpHg/Np/Op and H^/O /N, flames metal y&por via introduced. Flame temperatures ranged frcn 2000 to 2500 K, rise-velocities from ') to 15 A/sec. The question is discussed as to what extent thermodynamic equilibrium does exist in ! certain parts of) the flame. The meaning of local) flame temperature and its relation to calculated adiabatic temperature and excitation temperature is considered. Complications due to suprathenanl chemilisainescence and radiative njncquilibriun effects are discussed. Recombination of excess radicals causes an initial rise in temperature with height and leads to supratherm&l cheniluiiunäscence of metal lines and to continuous baci^round radiation. Radiative non-equilibrium JUUSOJ undorpopulation of excited metal states and cm be studied by excitation temperature measurements. From departures from aetal-ionization equl^ibrim conclusions are dravn about the lonization mechanism, effective cross-sections and relaxation times. Cheml-ionization is also dealt with. The negligible influence of excess 0-radicals in CO flames on the dissoclati'e equilibrium makes posslb.ito exclude particular dissociation reactions, r'roni the measured equilibrium populitlon of the visible aLKaiine-earth bands mo?ecular excitation energies were derived and conclusions about the kind of emitters were drawn.