Modelagem CFD de explosões de pós em silos

Abstract

One of the causes of accidents in silos is due to explosions. These are generated by the accumulation of suspended dust in a confined atmosphere, along with an ignition source and oxygen concentration capable of propagating a flame. The explosion can reach unimaginable proportions, causing property damage and loss of life. In conducting research on dust explosions is equally dangerous, as most trials are live threatening. Modeling studies are proposed to minimize costs and the high danger in conducting experimental studies. One of this phenomenon’s study methods is Computational Fluid Dynamics (CFD), which can accurately simulate a dust explosion. This study aimed at analyzing the mitigation of dust explosion using CFD, from boundary conditions using a larger number of variables. Dust of stored products were used taking as reference the influence of methane, released by degradation of grain silos. After several simulations it has been found that the ignition sources related to temperature are enhanced with the increase of methane concentration in a silo. A decrease in the minimum ignition temperature of the dust cloud, as well as a decrease of minimum ignition energy and minimum concentration of dust was also detected. Methane, as an inert gas in a silo, directly affects the increase in the probability of dust explosion, related to the release of the heat generated by the methane and its high ignition power.