Abstract:

In order to elucidate the combustion evolution mechanism under the interaction between gas explosions and deposited dust, combustion tests were conducted using an independently developed experimental platform for gas explosion-induced dust combustion. These experiments investigated the ignition of LDPE dust triggered by ethylene explosions, with data collected on pressure, temperature, and flame propagation behavior within the explosion chamber. A systematic analysis was performed to examine the effects of ethylene volume fraction and LDPE deposition mass on the explosion dynamics. The results demonstrate that explosion pressure-time curve exhibits a characteristic trend of initially increasing and then decreasing when ethylene concentration ranges from 3% to 7% and LDPE mass is 0, 0.5, 1, 1.5, 2, or 2.5 g. At the same LDPE dust mass, the time required to reach the peak pressure gradually decreases as the ethylene concentration increases. At the same ethylene concentration, the peak pressure of explosion remains relatively stable with increasing LDPE mass, whereas the peak explosion pressure increases significantly with increasing ethylene concentration. At different ethylene concentrations and LDPE dust masses, the temperature-time curves consistently exhibit an initial increase followed by a subsequent decrease. At a constant LDPE mass, the time required to reach the peak explosion temperature generally decreases as the ethylene concentration increases. When the ethylene concentration increases from 3% to the range of 4%-7%, the variation pattern of peak temperature with LDPE mass changes from a two-stage pattern of decreasing first and then increasing to a three-stage pattern of decreasing first, then increasing, and finally decreasing. At a constant ethylene concentration, the flame color changes from blue to bright blue and finally to yellow when LDPE mass is 0 g. As LDPE mass increases to 0.5, 1, 1.5, 2, and 2.5 g, the flame color transitions from blue to bright blue, then to bright yellow, and ultimately to dark red. At a constant ethylene concentration, the flame area, flame continuity, and combustion duration initially increase and then decrease as the LDPE mass increases.

Key words: ethylene explosion, low-density polyethylene(LDPE), deposited dust, combustion test, explosion pressure, explosion temperature, explosion flame