粉末燃料高效装填技术研究

Study on high efficiency packing technology of powdered fuel

分析了理想球形颗粒的堆积规律,发现粉体空隙率与粒径大小无关,仅与排列方式有关;多级配混合粒径装填会减小粉体的空隙率,且级数越多,粉体空隙率越小;颗粒在紧密堆积状态下排列方式不唯一,是多种密排形式的组合。研究了非理想颗粒的堆积规律,发现实际粉体颗粒间的干扰和干涉作用对颗粒装填率影响较大,颗粒形貌越不规则,粉体的装填率越小;颗粒越细小,则吸附力越大,粉体的装填率越小。基于以上分析,提出了理想的最紧密装填理论,确定了在多级配装填料中颗粒级数、粒径比以及各级颗粒的含量比例。最后,提出了一种简单有效的粉末燃料高效装填方法,通过实验验证,此方法可将粉末燃料的松装密度提高近10%。

The packing theory of ideal spherical particles was analyzed, and it is found that the voidage of powder is only related with the arrangement patterns and unrelated with the particle size;multi-grade spherical particles mixed packing can decrease the voidage of powder, and the more numbers of size fraction, the smaller void fraction of powder;the arrangement patterns of particles are not single at close packing status, but the combination of various compact arrangement patterns. The packing principle of real particles was studied, and it is found that the effect of interference between the particles has a great influence on packing ratio of powder, the more irregular particle shape, the smaller packing ratio of powder;the finer particle size, the stronger adsorption force, and the smaller packing ratio of powder. Based on the above analysis, an ideal closest packing model, in which the numbers of size fraction, diameter ratio of big/small particles and the mass proportion of each grade particles in multi-grade particles mixed packing were determined ,was established. Then a high efficiency packing method, which is a simple and feasible method for improving the packing ratio of powdered fuel, was proposed. Through experimental verification ,this method can increase the loose packing ratio of powdered fuel by nearly 10%.