Influence of the Pyrotechnic Igniter Composition Aging on Explosion Parameters of Dispersed Dusts

Abstract

A commercially available pyrotechnic igniter was used according to the EN 14034 and ASTM E1226a Standards to study the explosiveness of dispersed dusts. Its pyrotechnic composition consists of 1.2 g of zirconium (40% wt.), barium peroxide (30% wt.) and barium nitrate (30% wt.). The energy released during the combustion of that amount of composition is 5 kJ. The article investigates the influence of aging of the pyrotechnic composition in the igniter on its initiation parameters. In the study, igniters of different years from date of manufacture were used: Igniter 1, manufactured in 2021 (less than 1 year from date of manufacture), and Igniter 2 (more than 2 years from date of manufacture). The study was performed in the KV 150M2 explosion chamber with a volume of 365 L and the 20 L sphere chamber with a volume of 20 L. A standard sample of Lycopodium clavatum was used in the KV 150M2 explosion chamber. Magnesium and benzoic acid were used as the samples in the 20 L sphere explosion chamber. The experiment showed that the explosion pressure Pmax of the igniter with more than 2 years from date of manufacture decreased by up to 10%, while the value of the explosion constant Kst decreased by up to 40%. The attained results proved that aging of igniters affects their explosion parameters and measurement accuracy.

Comparative Analysis of Fire and Explosion Properties of Lycopodium Powder

“…The correctness of the application of standardized methods for determining ignitability and explosive parameters, as well as good understanding of obtained results, are, therefore, of primary importance. This underscores the importance of dusts used for validation and calibration [9][10][11][12], such as lycopodium. Although the parameters of basic dusts are relatively well understood, new ones continue to emerge, including hybrid mixtures, the presence of which can threaten worker safety, and explosion parameters should be labeled as accurately as possible.…”