大型管道中主动式粉尘抑爆现象的实验研究

Study on active explosion suppression by powder in large-scale duct

利用自行设计的简易主动式粉剂抑爆装置，在直径0．7m、长25m大型爆炸实验管中充入浓度8％-10％的甲烷空气混合物，采用电雷管起爆5g TNT起爆方式，对粉尘抑爆现象进行了实验再现，并对不同抑爆剂种类、浓度、粒度等抑爆剂参数下产生的抑爆效果进行了实验研究．结果表明：①抑爆剂种类是影响抑爆效果的重要因素之一；②对粒度相同的某种抑爆剂，浓度越大，抑爆效果越明显，且存在一个极限浓度，低于该浓度时，激波在押爆区不会被安全抑制，穿过抑爆区后会重新成长；③相同浓度下的某种抑爆剂，粒度愈小，抑爆效果愈好．

With a self-developed active suppressor of explosion used, the phenomena of explosion suppression by powder was observed experimentally in large-scale combustion duct, which was filled with 8% - 10% premixed methane-air mixtures and initiated by a detonator and 5 g TNT explosives, and the effectiveness of explosion suppression was examined by varying suppressant kind and mass concentration and particle size, respectively. The results showed that the kind of suppressant is one of important factors influencing its capacity of explosion suppression firstly. Secondly, when the same particle size of a suppressant is used, the higher mass concentration of suppressant is applied, the more prominent explosion suppression can be obtained. Moreover, there exists a critical value of mass concentration of suppressant, when mass concentration applied is lower than it, the shockwave will rebuild up and will not be suppressed completely after it traveling through suppresion zone. Finally, if the same mass concentration of a suppressant applied, the finer the ABC powder, the more prominent shockwave attenuation.