Experimental Study of Premixed Flames Stabilization with Al2O3 Porous Media

In the present research, stabilization of premixed flames with porous media is studied experimentally. First, for comparison, the effects of flame speed, equivalence ratio, and thermal power on the stability limit of a premixed free flame are investigated. Furthermore, the stabilization of the premixed flame with Al2O3 porous media is studied. Porous aluminum oxide ceramics with pore densities of 10, 20 and 30 ppm are used in the burner. Experiments are performed for 5 and 8 cm distances between the porous medium and the mixture outlet. The results show that the flame stability limit is independent of pore density and the flame is formed in the porous medium at all conditions at an equivalence ratio of about 0.55. Moreover the increase of porous medium distance from the burner causes the stability boundary in higher equivalence ratios. The amount of pollutants depend on distance and type of the porous medium. It is observed that the use of porous medium reduces NOX and increases CO in comparison with the free flame burner.