气力输送水泥粉体扑灭金属镁火灾研究

Research on the application of pneumatic conveying cement powder to extinguish metal magnesium fires

为了研究水泥粉体扑灭金属镁火灾的可行性,通过自行设计的水泥粉体气力输送装置开展金属镁火灾的灭火试验研究。介绍水泥粉体气力输送羽流模型。结果表明,采用气力输送原理可以实现水泥粉体的高效输送灭火,但过高的喷射高度会导致气体喷射速率明显下降,过低会因过高气体流速产生的冲击力发生回弹。灭火实验表明,将水泥粉体作为灭火剂可以有效扑灭金属镁火灾并表现出较好的抗复燃性能,主要灭火机理为物理窒息作用,其中金属镁火灾荷载越大,所需水泥覆盖层越厚,灭火时间也越长。

In order to study the feasibility of using cement powder to extinguish mental magnesium fires,experiment using self-de-signed pneumaticconveyingequipment for cement powder was car-ried out.The plume model of pneumatic conveying cement powder was introduced.The results showed that the pneumatic conveying system can transport the cement powder to the fire effectively,and the jet velocity of carrier gas is decreased with the increase of jet height,while jet height being too low will cause springback by the impact force produced by high gas flow velocity.The fire extin-guishing results revealed that the cement powder can serve as extin-guishing agent to extinguish the metal magnesium fires with good anti reignition performance by physical isolation effect,and the bigger the fire load,the thicker the cement powder layer needed,and the longer the extinguishing time.