Formation of Methane-Air Open Flame on the Surface of a Porous Ceramic Plate

Abstract

The paper presents the experimental results of the formation of a flame in premixed methane/air formed on the surface of a porous ceramic plate. The plate surface was heated to high temperature by the flame, and then the high radiative heat flux from its surface could be emitted. Various apparent shapes of the flame according to the shape of the plate were also observed. The methane-air mixture passing through the porous ceramic plate was ignited on the upper side. From the temperature and the component concentration profiles measured under open-flame conditions, it was concluded that when the superficial velocity of the gas was lower than the combustion velocity of the premixed laminar flame, a reaction zone of combustion was formed at a position in the close vicinity of the surface where the gas velocity was balanced with the combustion velocity reduced by interactions between the gas and the solid surface. The surface temperature of the ceramic plate was higher than 900K equivalence ratios between 1.0 and 1.8. A peak surface temperature was observed at a certain heat load, and it was shown that smaller pore diameter, smaller thickness or higher effective thermal conductivity of the ceramic plate decreased the surface temperature. Flashback was not generated under the experimental conditions carried out. © 1990, The Society of Chemical Engineers, Japan. All rights reserved.