Abstract: Porous media were investigated for the preparation of flame holders, for porous medias permeability and dispersivity can bring down pressure loss and improve the ratio of fuel and air after the bluff-bodies. Based on the comparative trials of a solid bluff-body and another two with 10PPI (pores per inch） and 40PPI, respectively, it was found that the porous media flame holder can have a wider range of flame stability. Under the same fuel and air co-flow conditions, a porous medium makes burning more complete, and the flame more rigid. The recirculation zone of a solid bluff-body is closer to the bluff-body and the back flow intensity is stronger than that of a body made of porous media. Hence, considering the pressure loss and the effects of fuel and air mixing, an appropriate diameter of porous media is the key to stabilizing flames.

Key words: porous medium, flame holder, extinction limits