Suppression effects of ABC powder on explosion characteristics of hybrid C2H4/polyethylene dust

• Suppression characteristics of two-phase explosion by ABC powder were investigated. • 1200 g/m 3 ABC powder can completely inhibit the explosion of 300 g/m 3 PE and 3% C 2 H 4 . • The C 2 H 4 gas makes the explosion of mixed system more difficult to be suppressed. • Base on thermal analysis, the suppression mechanism of ABC powder were discussed. In order to analyze the suppression effects and mechanisms of ABC powder on ethylene gas (C 2 H 4 )/polyethylene (PE) hybrid explosion, to explore the suppression characteristics of gas-solid two-phase explosion, the 20-L apparatus are used for the test of the explosion overpressure. The results show that when the volume fraction of C 2 H 4 is 3%, the concentration of ABC powder required to completely inhibit the explosion of 300 g/m 3 PE dust increases from 200 g/m 3 to 1200 g/m 3 . When increasing the volume fraction of ethylene to 5% and 7%, the explosion overpressure reduction in the mixture is 40.68% and 28.59%. The results of thermal analysis show that the addition of ABC powder improves the thermal stability of PE particle. Through the physical effects of heat absorption, oxygen insulation, and thermal transmission weakened and the chemical effect of eliminating explosive radicals, ABC powder reduces the rate of explosive chain reaction and heat release rate, thus producing an effective inhibition effect. But C 2 H 4 will induce the explosion process of the mixture from two-phase combustion to homogeneous combustion to promote the explosion, and its effect is opposite to that of ABC powder pyrolysis in the system, which makes the explosion of mixed system more difficult to be suppressed.