Na_3AlF_6对微米铝粉在CO_2气氛中着火燃烧特性的影响

为了改善铝粉在二氧化碳气氛中的着火特性和燃烧效率,采用自行设计的管式炉研究了六氟铝酸钠对铝/二氧化碳着火燃烧特性的影响。采用高速摄影系统记录了样品着火燃烧现象,同时收集反应后的产物通过X射线衍射和扫描电镜技术、化学分析方法对其成分、产物形貌和燃烧效率进行了分析。研究结果表明,六氟铝酸钠能够显著降低铝粉的点火延迟时间,与未添加六氟铝酸钠的样品相比,加入六氟铝酸钠后,样品的点火延迟时间降低了18s左右;六氟铝酸钠的加入还能抑制燃烧产物凝聚并提高铝粉的燃烧效率,随六氟铝酸钠添加量增加,燃烧效率呈现先增加后降低的趋势,添加了六氟铝酸钠的样品的最高燃烧效率为71.82%,与未添加六氟铝酸钠的样品相比提升了21.1%。

Effects of Na3AlF6 on Ignition and Combustion Characteristics of Micron-Sized Aluminum Powder in CO2

In order to improve the ignition and combustion characteristics and combustion efficiency of aluminum powder in carbon dioxide atmosphere, a self-designed tube furnace was used to investigate the effects of sodium fluoroaluminate on the ignition and combustion characteristics of aluminum/carbon dioxide. The high-speed photographic system was used to record the ignition and combustion of samples. The collected products were analyzed by X-ray diffraction, scanning electron microscope technique and chemical analysis method to obtain their composition, product morphology and combustion efficiency. The results showed that sodium fluoroaluminate can significantly reduce the ignition delay time of aluminum powder. Comparing with the sample without sodium fluoroaluminate, the ignition delay time of the sample reduced by about 18 s after adding sodium fluoroaluminate. The addition of sodium fluoroaluminate can also inhibit the coagulation of combustion products and improve the combustion efficiency of aluminum powder. The combustion efficiency first increased then decreased as sodium fluoroaluminate content increased. The highest combustion efficiency of the sample added with sodium fluoroaluminate was 71.82%, which was 21.1% higher than that of the sample without sodium fluoroaluminate.