Caracterización de la explosividad del polvo de madera

Abstract

Objective: The aim of this work is to characterise the factors that influence theexplosiveness of wood dust, such as particle size, particle size distribution,moisture content and microscopic structure.Methods: wood dust was tested in a modified Hartmann tube and scanningelectron microscopy images were taken. The Minimum Explosive Concentrationof raw samples and sieved portions was determined. Minimum IgnitionTemperature of dust clouds has also been measured. In addition, it has beenestablished the relationship between of the explosive limit values as a function ofmoisture and granulometry for the different wood dust samples.Results: Based on the results obtained, the samples have been classified intotwo groups, those from the cutting of the wood and those found in the ventilationducts and/or that are deposited over time. The second ones are the mostdangerous; both the fine fractions, with humidities up to 35 %, and the coarseones (greater than 500 micrometres) when at maximum dryness, are capable ofproducing an explosion.Conclusions: Both the particle size distribution or granulometry linked to theregularity of its structure, as well as the humidity are the essential parameterswhen it comes to generating or not an explosive atmosphere. More finely divided dust (smaller particle size) and whit a lower humidity degree is much more likelyto create an ignition and/or explosion risk.