Effect of local rearrangements in the particle bed on the stability of filtration combustion of solid fuel

The effect of local rearrangements in the particles bed during filtration combustion is studied experimentally and numerically. It is shown that for upward gas filtration and propagation of combustion front, there exists a stabilizing mechanism. It is due to filling of caverns formed as the result of burning-out of solid fuel by the fuel mixture from overlying layers. This mechanism prevents deformations and decay of the combustion front. The stabilization effect has a threshold for the gas flow rate that corresponds to the minimal fluidization gas velocity in combustion zone. In case of downward gas flow and combustion front propagation, this stabilizing mechanism does not occur.