Up to now, knowledge of characteristics of the Torin1 filtration combustion is still limited. Kamiuto and Ogawa  experimentally investigated the shape of the diffusion flame in cylindrical packed beds. Subsequently, Kamiuto and Miyamoto  experimentally and analytically studied the flame shape of diffusion combustion in a plane-parallel packed bed. The flame structure was viewed by gradually adding the alumina pellets with a height of 5 mm per time from the above of the burner. A theoretical flame sheet model, in which the horizontal mass dispersion effect in porous media can be taken into account, was presented. However, the vertical dispersion diffusivity was ignored. Several parameters which affect the flame shape were evaluated and discussed. It is shown that the flame sheet model can capture the flame shape for different pellet diameters and mixture velocities. However, the predicted flame widths were in general smaller than those of experimental results, this discrepancy between the prediction and experimental data was attributed to the neglecting of thermal radiation .