Importance of properly designing dust explosion protection systems: Case study – 2014 plywood manufacturing facility fire and explosion

Abstract

When designing handling and conveying equipment for combustible dusts, it is crucial to properly implement protective measures (e.g., deflagration venting, suppression, and isolation) capable of mitigating the potential consequences in the event the dust is ignited. Generally speaking, dust processing, storage, and collection equipment, such as cyclones, mills, baghouses, dryers, and silos are typically connected via pipes, pneumatic conveyors, and dust extraction or aspiration lines. If a fire or dust explosion occurs in one vessel, or the interconnecting piping, the flame front or pressure can quickly propagate through these conduits to other parts of the plant and potentially escalate to even worse consequences than the original event. Improper design of isolation devices can be costly, as illustrated by this case study on the fire and explosion in a baghouse that occurred on April 26, 2014 at a plywood manufacturing facility in Texas. More specifically, numerous deficiencies in the system design were identified, which included (1) required air stream flow rates; (2) proper isolation designs; (3) exclusion zones in the anticipated path of a vented deflagration; and (4) impeding deflagration vents. The root cause analysis identified that had a dust hazard analysis been properly performed, these deficiencies would have been identified and the explosion in the baghouse could have been avoided. © 2019 American Institute of Chemical Engineers Process Saf Prog: e12036 2019