An experimental study on the submerged flame in an alumina pellets porous medium

Abstract

In the present study, the conditions of the formation of a submerged stable flame in an alumina pellet porous burner are investigated. The effect of firing rate, equivalence ratio, and inlet mixture velocity on the flammability limit, flame position and flame temperature is studied experimentally. Different pellet diameters (5, 7, 13, and 20 mm) are used to construct various porous media. The sidewall temperature of the porous burner is measured with several thermocouples. The obtained temperature profile for different cases is used to determine the submerged flame location. For each case, a stability limit for the submerged flame is obtained versus the equivalence ratio and inlet mixture velocity. The experiments show that with decreasing the equivalence ratio, the maximum temperature decreases and the flame begins to move downstream of porous media and finally exits from it. It was shown that dimensionless maximum flame temperature is a function of the equivalence ratio and does not depend on pellet diameters.