Analytical thermodynamics models of gas explosions have been used for relating pressure-time data to flame speeds. Although these models are directed towards gas explosions, researchers have applied them to constant volume dust explosions. In this study, the validity of these relations for dust flames was tested experimentally. Sulfur is the ideal candidate for such a study since it has features of both gaseous and condensed phase fuels. Tests were conducted in an optically accessible, 31 L dust explosion chamber. Combs of ionization probes were used to determine the location and speed of the sulfur flame front in two directions. The flame speeds from these probes were compared to the speeds predicted from pressure-time data. Results showed that the turbulence created a flame without spherical symmetry as the flame speed varied with direction and test to test. Some agreement was observed between the laminar flame speeds measured by the ionization probes and pressure-time data. Despite these results, this approach should only be used if more appropriate techniques are unavailable.
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