Radiative ignition properties of food grains and surface temperatures at ignition

Abstract

Fire safety of food grains in storage, transport and processing facilities requires knowledge of their ignition properties some of which have been determined in this study. Cowpea, lentils, millet, soybean, unshelled peanut, flax (linseed), sunflower, shelled peanut and sesame, at 10% moisture content were studied. A cone calorimeter heater was used to impose radiative heat fluxes of 25, 35 and 47.5 kW/m2 on the food grains to determine the time to piloted ignition concurrently with the surface temperature at ignition ( Ts,ig). Ignition temperatures ( Tig) were calculated from experimentally determined critical heat fluxes. The thermal response parameter and thermal inertia ([Formula: see text]) essential for the characterization of the ignition of the food grains were also calculated. Thermal response parameter appears to be best suited for distinguishing the ignitability of the food grains. Ignition temperatures range between 239°C and 305°C, while thermal response parameter varies between 261 and 565 kWs0.5/m2. Small particle-sized grains showed higher ignitability.