抑制铝粉尘云爆炸的粉体材料效能对比分析

Comparative analysis of the effectiveness of powder materials on suppressing aluminum dust cloud explosion

为降低铝粉尘云爆炸事故危害程度,有必要探索对其有效的抑制性粉体材料。采用瞬态火焰传播实验系统研究ABC粉、MCA粉和MPP粉对铝粉尘云爆炸的抑制效能,并深入分析优选阻燃粉体材料MPP粉对铝粉燃烧的抑制机理。研究结果表明:针对质量浓度为375 g/m3铝粉尘云,MPP粉、MCA粉和ABC粉质量浓度分别为70.31,93.75和140.63 g/m3时,铝粉尘云爆炸能够被彻底抑制。3种阻燃粉体材料中,MPP粉对铝粉尘云爆炸的抑制效果最好。在0~612.5°C,MPP分解吸收大量热,分解产生的惰性气体NH3和H2O会降低金属颗粒附近的氧气浓度。此外,分解产生的磷系自由基也会反应进一步消耗掉氧原子。铝粉在加热过程中,被氧化铝薄膜包裹着的内核铝受热膨胀突破氧化膜,开始快速氧化,而MPP粉的加入推迟了这一过程。分解吸热、降低氧化剂浓度以及消耗氧原子的综合作用导致MPP粉对铝粉尘云爆炸具有较好的抑制效果。

Exploring effective inhibitory powder materials is necessary for reducing the damage degree of aluminum dust cloud explosion accident.The transient flame propagation experiment system was used to study the suppression effect of ABC powder,MCA powder and MPP powder on aluminum dust cloud explosion.The suppression mechanism of the preferred flame retardant powder material MPP powder was investigated.The results show that for aluminum dust cloud with mass concentration of 375 g/m3,when MPP powder,MCA powder and ABC powder mass concentrations are 70.31,93.75 and 140.63 g/m3,respectively,the explosion can be completely suppressed.Among the three flame retardant powder materials,MPP powder has the best suppression effect on aluminum dust cloud explosion.In the range of 0-612.5°C,MPP decomposes and absorbs a lot of heat.Meanwhile,the inert gas NH3 and H2 O generated by the decomposition of MPP powder reduces the oxygen concentration near the metal particles.Phosphorus radicals generated by the above decomposition also react and consume oxygen atoms.During heating aluminum powder,the core aluminum wrapped by the alumina film expands by thermal expansion and breaks through the film.The addition of MPP delays this process.The combined effects of endothermic decomposition,reduction of the concentration of oxidizer and consumption of oxygen atoms lead to the MPP powder with a better inhibitory effect on the aluminum dust cloud explosion.