SUPERADIABATIC COMBUSTION OF METHANE AIR MIXTURES UNDER FILTRATION INA PACKED-BED

Filtration combustion in porous media differs substantially from combu stion in a homogeneous media. The difference is the heat transfer betw een the filtrated gas and the porous medium under conditions of active heat transfer over a highly developed internal solid surface. The rea ctive transfer is characterized by a thermal wave velocity that determ ines the velocity of heat accumulation in a porous medium due to the f iltrated flow and by a reaction wave velocity. A resonance condition c an occur when both velocities nearly coincide and the heat of reaction becomes localized in a moving thermal wave. A temperature can be reac hed much in excess of the adiabatic reaction temperature and thus self -propagating reactions are possible even in a weakly exothermic medium . The propagation of the localized resonance wave and the superadiabat ic reaction effect is confirmed by experiments and the results of a si mple mathematical analysis. The model is compared with predictions for the thermal and combustion wave speeds and demonstrates good agreemen t.