The fundamental properties of dust flame propagation have been studied experimentally and theoretically. Experiments were carried out in a Pyrex tube having a 5 cm inside diameter and a length of 1.2 meters. The dust dispersion system in the present experiment has been demonstrated to produce a laminar flow with uniform dust concentration. It is observed that the propagating flame exhibits a truly laminar character of propagation. Propagation and quenching of dust-air flames were measured for aluminum dust for a relatively wide range of dust concentration. It was observed that the process of the dust flame propagation in the tube can be divided into three different stages: laminar flame, oscillating flame and turbulent accelerating flame. During the first stage, the flame propagates with approximately constant speed and the flame is laminar. This stage is about 1/3 to 1/2 of the tube length and the shape of the flame front during this phase is close to the usual parabolic shape. In the second stage, flame starts to oscillate. Bright regular flashes alternate with stages when the flame is almost invisible. The third stage of the flame propagation can be observed only if the dust concentration is close to or higher than stoichiometric. The quenching distance and flame velocity of an aluminum dust flame under different initial oxygen concentrations and with different inert gases such as helium and nitrogen were also measured. When the amount of the initial oxygen concentration decreases, both the quenching distance and the lean limit increase, while the flame velocity decreases. On the other hand, after using helium as the inert gas of the mixture, it was observed that the whole value of the quenching distance, the lean limit, and the flame velocity increase. However, the objective is to understand the mechanism of the dust flame propagation. Theoretical models have also been developed to correlate the data to achieve a better understanding of the propagation mechan
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.28682 |
| Date | January 1995 |
| Creators | Bidabadi, Mehdi |
| Contributors | Lee, J. H. S. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Mechanical Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001448043, proquestno: NN05673, Theses scanned by UMI/ProQuest. |
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