采用泄爆管的粉尘爆炸在泄放过程中的压力特性

以2m 铝粉为介质,在内径68mm、高305mm 的钢制圆柱容器顶端连接内径25mm、不同长度的钢制泄爆管,开展了粉尘爆炸泄放实验。通过分别改变泄爆管长度及粉尘的质量浓度,研究粉尘爆炸泄放过程中容器及泄爆管内的压力特性,重点在探索泄放过程中二次爆炸发生的条件。结果表明,在本实验条件下,当泄爆管长度LT1500mm,粉尘质量浓度500g/m3 时,泄爆管内发生二次爆炸的几率很高。二次爆炸产生的压力波分别向爆炸容器及泄爆管末端2个方向传播。向爆炸容器传播的压力波阻碍并扰乱泄放过程,导致容器内残余未燃粉尘反应,使容器内压力出现二次峰值。

Pressure characteristics in dust explosion relief process by using a relief pipe

Thealuminumpowderof2μmparticlesizewastakenasthemediumandaseriesofdustexplosionreliefexperimentswerecarriedoutbylinkingthesteeleliefpipeswith25mminternaldiametertothetopofthecylindricalsteelvesselwith68mminternaldiameterand305mmheight.Thesteelreliefpipelengthandthedustmassconcentrationwereadjusted,respectively,toinvestigatethepressurecharacteristicsinthevesselandthereliefpipeandtoexploreprincipallythesecondaryexplosion-inducedconditionintheexplosionreliefprocess.Experimentalresultsdemonstratethatsecondaryexplosionmayoccurwhenthereliefpipelengthanddustmassconcentrationarenolessthan1500mmand500g/m3,respectively.Thepressurewavesinducedbysecondaryexplosionpropagatetowardboththevesselandthereliefpipeend.Thepressurewavespropagatingtowardthevesseldisturbthereliefprocessandinducetheresidualunburntcombustiblemixtureinthevesselreact.Hence,secondarypressurepeakappearsinthevessel.