Effect of energy and design of ignitor on dust explosion characteristics

Abstract

The type of ignition plays a crucial role in dust explosion measurements. To date, research on the ignition part has mostly focused on ignition by electric spark, or pyrotechnic ignitor, with various energies. Only a few works focus on the use of different types of pyrotechnic ignitors and different pyrotechnic mixtures. This work examines the effect of the pyrotechnic ignitor’s energy, design, and pyrotechnic composition on the measurement of safety parameters of combustible dusts. Measurements were carried out with lycopodium in a 20 dm3 explosion chamber, recording the pressure and output voltage from the optical probe. A high-speed imaging technique were used to investigate ignitors behaviour. In summary, the ignitor type and its energy have significant effect on measured explosion parameters. It was shown that burning of the pyrotechnic mixture in the Standard Sobbe ignitors overlaps ignition and burning of Lycopodium dust itself. Squibs burn for a shorter time while producing a significant pressure wave which acting on the dust cloud, causing its disturbances and influencing explosion parameters