超细二氧化硅粉体对淀粉火焰抑制的实验研究

Experimental investigation on suppression of starch flame by ultrafine silicon dioxide powders

为了探究不同粒径二氧化硅粉体抑制效果上的差异,采用小尺寸竖直燃烧管道系统,研究添加10μm和30nm二氧化硅粉体时,不同粒径小麦淀粉燃烧的火焰传播、温度、速度等参数特性的变化。实验结果表明:超细二氧化硅粉体能减弱小麦淀粉燃烧反应强度;30nm二氧化硅粉体抑制效果优于10μm二氧化硅,当小麦淀粉粒径小于25μm时,质量浓度为0.43kg/m^3、粒径30nm的超细二氧化硅粉体可使小麦淀粉火焰亮度明显下降,最高温度下降38.07%,最大速度和平均速度分别下降42.25%、65.59%;超细二氧化硅粉体主要起物理抑制作用,抑制效果与小麦粒径成反比关系,小麦粒径越小,二氧化硅抑制效果越好。

It is well known that the ultrafine silicon dioxide powder has a certain suppressing effect on the wheat starch flame.In this work,we explore the difference in this effect on the silicon dioxide powder due to different particle sizes,the changes of flame propagation,temperature,velocity and other parameters of the wheat starch combustion by adding 10μm and 30 nm silicon dioxide powders.The experimental results show that the ultrafine silicon dioxide powder can reduce the wheat starch's burning reaction strength.The 30 nm powder produces a more effective suppression than the 10μm powder.When the wheat starch powder's particle size is below 25μm,The ultra fine powders with a mass concentration of 0.43 kg/m^3 and a grain size of 30 nm can significantly decrease the wheat starch's flame brightness,reducing its maximum temperature by 38.07%,its maximum and average velocities by 42.25%and 65.59%,respectively.The ultrafine silicon dioxide exerts mainly an effect of physical suppression,which is inversely proportional to the particle size of wheat starch grains.The smaller the wheat starch grain size,the better the effect of silicon dioxide suppression.