Energy and chemical grounds of limiting concentrations for coal dust and methane combustion and explosion

I.E. Kolesnichenko, V.B. Artemiev, E.A. Kolesnichenko, V.G. Cherechukin, E.I. Lyubomishchenko

The authors suppose that methods of scientific grounding of the mass concentration lower limit for ignition (LMCL) of the combustible matter must take into account energy characteristics of the interaction of combustible chemical elements entering into chemical reactions. The article contains new definitions of the combustible matter and combustible chemical elements of coal. The authors substantiate their methods of quantitative estimation of energy consumption for breakdown of coal and methane combustible matter molecules into combustible elements, and evaluation of energy liberated in the process of exothermal reactions. They introduce a concept of energy reproduction by combustible materials. On the basis of the molecular-kinetic theory they calculated the dependences of temperature and excess pressure resultant from the combustible matter thermal energy release. The description is provided of the mechanism of chemical reactions propagation in the combustible medium as a result of energy reproduction by combustible materials. The article presents the technique of coal dust LMCL estimation and a graphic example of calculations for the conditions of the Breevsky coal seam. Besides, methods are described of the substantiation of the most explosion-prone coal dust size ranging from 40 to 50 m. The article also contains the results of calculations showing that in the combustible medium of underground mine workings the propagation of combustion goes at a high rate, and due to low excess pressure there are no conditions for the formation of a blast wave.

№4 (128) 2016

Key words: coal dust, methane, explosion hazard, molecular.kinetic theo. ry, combustible chemical elements, energy reproduction

Mining Industry Journal №4 (128) 2016, p.61