Gas-phase and catalytic combustion in heat-recirculating burners

摘要: Abstract An experimental study of a spiral counterflow “Swiss roll” burner was conducted, with emphasis on the determination extinction limits and comparison results without bare-metal Pt catalyst. A wide range Reynolds numbers ( Re ) were tested using propane–air mixtures. Both lean rich extended catalyst, though much further. With combustion could be sustained at as low 1.2 peak temperatures 350 K. heat transfer parameter characterizing thermal performance both gas-phase catalytic all identified. At , “lean” limit actually stoichiometric, rich-limit had equivalence ratios exceeded 40 in some cases. No corresponding behavior observed Gas-phase combustion, general, occurred “flameless” mode near center. or for sufficiently robust conditions (high near-stoichiometric) not requiring recirculation, visible flame would propagate out center, but this only re-centered if catalyst present. Gas chromatography indicated that even extremely mixtures, CO non-propane hydrocarbons did form. For higher where occur, slightly broader lower temperatures. high merged. It is concluded heat-recirculating burners greatly benefits from proper choice mixtures are different those preferred combustion. In particular, importance providing reducing environment to enhance O 2 desorption, especially losses severe thus low, noted.