Flame Spread in CH4/Air and CH4/Air/Coal Dust Mixtures in a Closed Vertical Channel
A. V. Pinaev, P. A. Pinaev
Lavrent'ev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: vertical channel, combustion wave, methane, coal dust, dual-fuel heterogeneous mixture, lower flammability limit, flame spread, fire safety
Abstract
We investigated the possibility of the existence of combustion waves in CH4/air mixtures with a methane content α = 5-8 vol.% and in CH4/air/coal dust mixtures in a closed vertical channel 6.75 m long and 0.07 m in diameter when ignited at the top. The experiments were carried out at an initial pressure of 0.1 MPa using dust with an average volume concentration of 100-530 g/m3 and a particle size 0-200 mm. It was found that combustion was not initiated in gas and gas/coal dust mixtures with α ≤5-5.5 vol.%. The results of the study indicate that the direction of gravity influences the ignition and combustion of the mixtures and that the energy contribution of coal particles is low compared to that of methane.
|
