An experimental study on submerged flame in a two-layer porous burner

Abstract

Combustion in porous media is an effective method to minimize dissipations and save energy.Therefore,Study on the porous burners has been the focus of many researches in the past decade, due to the favorable features of these burners.The conditionsfor the formation of a steady-state submerged flame in a ceramic (SiC) porous medium were investigated at four firing rates. The results were obtained on a ceramic foam with a cross section area of 63.6 cm2and pore density of either10 or 30 ppi. The reactants were air and natural gas with various equivalence ratios. In this experimental study, eightthermocouples were mounted on the burner walls along its axis in order to track the flame position, and the results were presented as temperature profiles of the porous wall. It was observed that the formation of submerged flame depends on firing rate and equivalence ratio. The stability limit of submerged flame (the range between surface flame and flash back limits) is reduced by increasing the firing rate. Results show when the mixture velocity low, the stability limit extends. Finally, the ranges of equivalence ratio and mixture velocity for the formation of submerged flame are presented at various firing rates.