Suppression of gas detonation by a dust cloud at reduced mixture pressures

Abstract

The decay of a detonation wave in a CH 4 +2O 2 + N 2 mixture propagating through a dust cloud is experimentally studied for three types of silica sand with particle sizes δ = 250-600, 120-250, and 90-120 µm, mean volume densities ρ s = 2.2-3.5 g/l, and initial pressure p 0 = 0.1-0.01 MPa. A non-monotonic character of reduction of wave velocity in the dust cloud is observed, where a secondary detonation can arise behind the leading front of the wave in the course of its attenuation. This situation is induced by the dual role of sand particles in decelerating the flow and simultaneously generating hot spots that promote reaction excitation. As a result, the mechanism of ignition in the decaying detonation wave becomes different. Critical parameters of the dust cloud providing complete suppression of the detonation wave and the flame propagating behind the latter at a reduced initial pressure of the gas mixture are determined.

Retracted: Effect of coal dust parameters on gas‐coal dust explosions in pipe networks

“…As the gas reaches a certain concentration and absorbs significant amounts of heat, a chain reaction will occur. The heat released by oxidation will cause particle flashover, and at a certain point, the explosion power will increase 3–6 . In pipeline gas explosions, the explosion intensity will increase significantly after mixing with coal dust.…”

“…The heat released by oxidation will cause particle flashover, and at a certain point, the explosion power will increase. [3][4][5][6] In pipeline gas explosions, the explosion intensity will increase significantly after mixing with coal dust. In addition, the distance between the maximum explosion pressure of the hybrid explosion…”