中文摘要：

20L球型爆炸罐是用于测试粉尘爆炸特性参数的标准装置之一。粉尘颗粒在密闭空间内的运动规律,对于研究粉尘的最佳点火延迟时间段有重要的作用。基于计算流体力学理论,对20L球型罐内的吹粉过程进行了数值模拟,监测了不同粒径的铝粉颗粒在20L球型罐内的分散情况,对比了不同铝粉颗粒粒径在罐内的沉降时间。结果表明：粉尘沉降的时间段随粉尘粒径的增大而减小,颗粒大小超过一定尺寸时,铝粉将不能在密闭空间内均匀扩散。

英文摘要：

20 L spherical explosion tank is one of the standard devices used to test the dust explosion charac- teristics parameters. The motion law of dust particle in closed space is useful for the study of the best ignition delay time in dust explosion. The dust flow process in 20 L spherical tank was investigated by numerical simu- lation based on computational fluid mechanics theory. The dispersion condition of aluminite particle of differ- ent sizes was monitored, and the particle subsidence times of different sizes were compared. It is shown that the particle subsidence time decreases as the particle size increases. When the particle size is bigger than a cer- tain degree, the dust will not disperse in the closed space.