Spontaneous combustion of hay

摘要: It is shown that spontaneous combustion most likely to occur in moist biological materials when they are equilibrium with a fairly narrow range of relative humidities (R.H.) between 95% and 97%. Experimental results on the adiabatic heating hay up ignition temperature confirm this theory. At lower R.H. no appreciable bacterial action takes place, at higher values, thermal conductivity increases so rapidly due water vapour transfer, microbiological maximum about 76° not exceeded. Chemical reactions can heat temperatures, only presence moisture; dependent previous microbial activity probably involve direct oxidation cellulose. 170° has dried out dry leads combustion.