The Collaborative Innovation Center of Safety Production of Henan Province, Henan Polytechnic University, Jiaozuo, 454003, Henan, PR China; State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Jiaozuo, 454003, Henan, PR China.
The Collaborative Innovation Center of Safety Production of Henan Province, Henan Polytechnic University, Jiaozuo, 454003, Henan, PR China.
J Hazard Mater. 2018 Aug 5;355:25-33. doi: 10.1016/j.jhazmat.2018.04.070. Epub 2018 Apr 27.
To investigate the effect of blockage ratios on the explosion suppression by powder suppressant, an experimental study was performed to suppress the methane-air explosion in a 5L duct with different blockage ratios and various concentrations of BC dry powder. The results indicate that flames experienced both the spherical and finger-shaped stages. Furthermore, the smoothness of flame front initially decreased and then increased. Flame propagation velocities were higher with larger blockage ratios except for φ = 1. The maximum peak overpressure (MPP) with the blockage ratio was slightly increased till φ reached 0.7 then surged sharply. The MPP decreased as the powder concentration increased. The maximum drop rate in the MPP being 34.8%-59.9%, depending on powder concentrations, occurred at the blockage ratio between 0.4 and 0.6. The result is ascribed to the competition between the suppression augmentation by the higher venting-generated turbulence and the suppression attenuation by the shorter residence time of the particle. However, the drop rate was relatively less promoted by increasing the concentration from 80 g/m to 240 g/m. The inhibitor at higher concentration was less effective. An inhibition mechanism is explained by analogy to droplet group combustion, in which the decomposition regime of NaHCO differs at different concentrations.
为了研究堵塞率对粉末抑制剂抑制爆炸的影响，进行了一项实验研究，以抑制不同堵塞率和不同浓度 BC 干粉在 5L 管道中的甲烷-空气爆炸。结果表明，火焰经历了球形和指形阶段。此外，火焰前缘的光滑度最初降低，然后增加。火焰传播速度随着堵塞率的增加而增加，除了 φ=1 以外。最大超压峰值（MPP）随着堵塞率的增加略有增加，直到 φ 达到 0.7 然后急剧上升。随着粉末浓度的增加，MPP 降低。最大 MPP 下降率为 34.8%-59.9%，具体取决于粉末浓度，发生在堵塞率在 0.4 到 0.6 之间。这是由于较高的通风产生的湍流增强抑制和颗粒停留时间缩短引起的抑制衰减之间的竞争所致。然而，通过将浓度从 80g/m 增加到 240g/m，下降率的促进作用相对较小。较高浓度的抑制剂效果较差。通过类比液滴群燃烧来解释抑制机制，其中 NaHCO 的分解状态在不同浓度下有所不同。
