Use of the Carbon-Hydrogen Ratio as an Index in the Investigation of Explosions and Underground Fires.

The Systematic Studies of the causes and nature of underground explosion and fires in mines often need assessment of the gaseous atmospheres in the affected area. The composition of the post-explosion gases due to dilution caused by large expansions and compressions during explosions may give an illusive picture of the real explosion chain reaction. A methodical approach is proposed in which the carbon-hydrogen ratio of the actual fuel participated, may be usefully employed to distinguish the nature of explosion i.e. to attribute the cause to the commonly occurring firedamp or to less frequently occurring but more violent coal dust explosions. The index, which may act as guide-line for the assessment may be calculated from the analysis of gaseous products. A number of cases of accidental as well as experimental explosions has been examined and broad agreements with the observations and circumstantial evidences actually related to the explosions, have been found. Limitations and possibilities in the scope of use of the index, discussed. The paper also includes how the proposed index may be utilized in assessing the qualitative and quantitative nature of fire by carefully co-ordinating the results of periodic gas analysis from the sealed off area with the index.