DryPro: Dangers of Vapor – Dust Explosions: Practical Consideration for Hybrid Deflagrations

In process facilities, the risk of an industrial explosion always exists. The risk can be reduced or minimized with proper deflagration protection; either administrative or engineered. However, for that protection to be optimally effective it should be based on genuine experimental data. This data may be readily available for gases and vapors. Explosibility data for dusts are commonly sample-specific and not material-specific; thus, data for the actual process dust is required. The data may have been previously generated during a safety review. But often safety reviews overlook the added complexity of a hybrid mixture (dust in the presence of gas/vapors). In a hybrid mixture the vapor from a solvent or a process gas can exacerbate the explosion severity and ignition sensitivity of dust. If these considerations were neglected during the Dust Hazards Analysis (DHA) then the explosion protection schema may be insufficient to mitigate the hazard because it relied only on dust cloud explosibility data.