Catalytic combustion of pre-vaporized liquid fuel

Fundamental characteristics of the catalytic combustion of vaporized kerose ne spray,were experimentally investigated This stum. is a parr of the devel opment of a ceramic gas turbine engine for automobiles. Kerosene was used a s a rest fuel and its spray was injected from a swirl atomizer into a hot a ir stream. The infer air temperature was elevated up to 900 K to vaporize t he kerosene spray, Premised gas of air and kerosene vapor was introduced in to the catalyst, The total equivalence ratio was controlled from phi = 0.18 -0.32. The palladium catalyst was supported on a cordierite honeycomb monol ith. Catalytic combustion phenomena were categorized in three typical state s: (a) state of partial reaction in the catalytic monolith, (b) state of ho mogeneous reaction in the monolith, (c) state of homogeneous reaction with a blue flame supposed on the monolith. A parabolic shape blue flame in the state of (c) appeared downstream of the monolith, This flame was very stabl e and its temperature was relatively low compared with conventional premixe d flames of hydrocarbon fuel because the equivalence ratio was much lower t han those of premixed flames, The distance from the monolith to the ignitio n point of this flame became short with a rise of the inlet air temperature , even if the volumetric airflow rate increased with the air temperature. S pontaneous emission spectra of radiation from the blue flame were measured. Strong spectral peaks of OH, CH, and CO+ radicals were observed in the spe ctra. This spectral structure was quite different from that of a blue flame of premixed propane.