Important explosibility parameters (e.g., maximum explosion pressure and standardized maximum rate of pressure rise) are described in terms of their relation to explosion causation, prevention and mitigation.
This study presents explosion characteristics (maximum explosion pressure, deflagration index and minimum explosible concentration) of two torrefied wood samples and compares their reactivity to that of their corresponding untreated biomass materials and to a sample of Kellingley coal.
The explosibility parameters investigated for both flocculent materials include maximum explosion pressure (Pmax), size-normalized maximum rate of pressure rise (KSt), minimum explosible concentration (MEC), minimum ignition energy (MIE) and minimum ignition temperature (MIT).
Dust explosibility is traditionally described by two parameters, namely the maximum explosion pressure, Pmax, and the deflagration index, KSt, usually determined through testing in a closed, pressure-resistant spherical vessel, either 20 L or 1 m3 in volume.
Experimentation was conducted by following standardized test procedures and using standardized apparatus for determination of maximum explosion pressure, size-normalized maximum rate of pressure rise, minimum explosible concentration, minimum ignition energy, and minimum ignition temperature.
The explosion parameters investigated are: maximum explosion pressure (Pmax), maximum rate of pressure-rise (dP/dt)max, dust explosibility index (KSt), minimum explosible concentration (MEC), minimum ignition energy (MIE), minimum ignition temperature (MIT), limiting oxygen concentration (LOC) and effect of reduced oxygen level on explosion severity.
The experimental results show that maximum explosion pressures are similar when different ignition sources are used.
However, when the gas mixture is ignited in the small vessel, the maximum explosion pressures in the large vessel and in the small vessel both decrease.
The maximum explosion pressures are: 8.6, 8.4, 8.2 and 8.0 bar in 20-L sphere, 27-L cubical vessel, 0.8 m3 rectangular vessel and 25.6 m3 sphere, respectively, at φ=1.05.
The experiments were carried out in a 20-L explosion vessel and the analysis of the results focuses on the maximum explosion pressures and the maximum rates of pressure rise as a function of carbon black and propane concentrations.
The maximum hydrogen explosion pressure, the maximum rates of pressure rise and the time delay between ignition in the big and small vessel are discussed.
