Effect on ignition sensitivity of combustible dust particle size reduction due to dispersion in the 20-L chamber

Abstract

This work simulates the particle breakage process caused by the dispersion of several typical combustible dusts in a 20-L chamber. Some operations in the process industry that involve gas turbulence and particle interactions can cause dust particles to break, resulting in a decrease in minimum ignition energy (MIE) and minimum ignition temperature (MIT). Particle breakage classification should attempt to correlate changes in D3,2 (Sauter mean diameter) values with the brittleness index. The descending order of particle breakage severity is as follows: ascorbic acid > anthraquinone > tobacco > nicotinic acid > lignite. The percentage decrease in MIE and MIT values is generally proportional to the degree of particle breakage. However, the decrease in MIT values was not as significant as in MIE values. This is because of the various dust-ignition source interaction patterns between a dust cloud and an ignition source.