堆积密度对棉花阴燃特性及残留物形貌的影响研究

Effect of density on the smoldering process and residues of cotton

为研究棉花在加工和使用状态下的阴燃情况,选用密度分别为20、40、60、80 kg/m3的棉花块,采用底部加热的方式进行试验,研究了密度对阴燃特性及残留物的影响。结果表明,随着密度的增大,棉花样品的孔隙率、空气渗透系数发生变化,临界阴燃温度升高约35℃,蔓延速率降低50%~60%,阴燃持续时间从2 500 s延长至5 000 s,阴燃结束后的收缩程度减小,坍塌程度增大。阴燃残留物为黑色絮状物包裹内部灰白色灰烬,灰烬体积随密度增大而增加。研究结论可以为棉花阴燃火灾的预防与火场勘验提供参考。

In order to study the smoldering of cotton in the pro-cessing and usage state,cotton with densities of 20,40,60,80 kg/m3 were selected in this paper.The bottom heating method was used to carry out the experimental study.The effect of den-sity on smoldering characteristics and residues was analyzed.The results show that with the increase of density,the porosity and air permeability coefficient of the sample change,so that the critical smoldering temperature increase by about 35℃,the spreading rate decrease by 50%~60%,and the smoldering duration in-crease from 2500 s to 5000 s.After smoldering,the shrinkage degree decreases and the collapse degree increases.The smolder-ing residue is a black flocculent covering the inner gray ash,and the ash volume increases with increasing density.The results can provide reference for the prevention and investigation of cotton smoldering fire.