(80g) Development of a Model for the Prediction of the Ignition Properties of Combustible Dusts Undergoing Homogeneous Combustion: Application to Sulfur Dust.

The determination of ignition properties such as the Minimum Explosible Concentration (MEC) and Minimum Ignition Energy (MIE) is critical for the control of the risks associated with combustible dust explosions. These properties are currently determined experimentally at laboratory scale using standardized tests. These tests are associated with several limitations: the tests require significant time and resources and the results are sample-specific. The particle size distribution of the samples may also get altered during testing by the equipment. This presentation describes a novel approach for the determination of the MEC and MIE of combustible dusts undergoing homogeneous combustion, using sulfur dust as a case study. The proposed model is based on the modeling of the heat and mass transfer phenomena occurring when a sulfur dust particle in a control volume is exposed to a planar hot surface acting as an ignition source. The model predicts the increase in temperature of the dust particle, its fusion, and vaporization in the control volume. An ignition criterion was developed on the basis of the accumulated amount of sulfur vapor and energy in the control volume. The model was used to predict the influence of the dust particle diameter on the MEC and MIE of combustible sulfur dust.