微米和纳米钛粉尘层着火蔓延特性研究

Study on Ignition and Flame Spread Characteristics of Micron and Nano Titanium Dust Layers

为了解微细钛粉的层火灾危险性,采用标准热板测试装置和自制的粉尘层火蔓延实验装置,研究了微米和纳米钛粉尘层最低着火温度和火蔓延速率变化规律,并验证了热爆炸理论模型和粉尘层火蔓延速率模型的适用性.结果表明:钛粉尘层最低着火温度随粒径减小而降低,33μm钛粉和60~80 nm钛粉的粉尘层最小着火温度分别为>400℃和230℃,与Thomas模型计算结果基本吻合;钛粉的层火灾危险性受粒径影响较大,实验测得微米和纳米钛粉的粉尘层火蔓延速率分别为13.60和500.57 mm/s,均大于理论模型计算结果.研究结果对微细钛粉的层火灾安全评价和工业防火防爆设计具有参考价值.

In order to understand the layer fire hazard of fine titanium powders,the minimum ignition temperature(MIT)and flame spread velocity(FSV)of micron and nano titanium dust layers were studied by using standard hot plate test device and self-made dust layer flame spread experimental device.The applicability of thermal explosion theory model and FSV model was verified.The results showed that the minimum ignition temperature of titanium dust layer decreases with the decrease of particle size,and the MIT of 33μm titanium powder and 60~80 nm titanium powder dust layer are>400℃ and 230℃,respectively,which are basically in consistent with calculation results of Thomas model.The fire hazard of titanium powder layer is greatly affected by particle size.The experimental results showed that the FSV of the dust layer of micron and nano titanium powder are 13.60 and 500.57 mm/s,respectively,which are larger than those calculated by the theoretical model.The results can be used as reference for fire safety evaluation and industrial fire protection design of fine titanium powder.