一种评价颗粒堆积效果的简便方法及其应用

A Simple Method for Evaluation of Particles Packing Efficiency and Its Application

提出一种评价颗粒堆积效果的简便方法,将颗粒划分为多个窄粒级进行隔层充填,基于匀相微元假设,通过计算上隔层空隙率的方式计算堆积评价指标E,以此评价颗粒堆积效率,并通过水煤浆制备试验验证其可行性.结果表明,E值越大堆积效率越高,成浆浓度随之呈增大趋势,说明了方法的有效性；对于不同的煤样,E具有最优值,颗粒堆积效率足够高,且不会因为过度堆积影响流动性；Rosin-Rammler拟合模型的均匀性系数n为0.7～0.8时,E值较大,但是通过n值判断堆积效率的优劣时会因拟合误差过大而存在失效的可能性；煤样氧化后的E值即使大于氧化前的,其成浆性仍可能降低；同一种煤制得的水煤浆,体积膨胀率具有一致性.

A simple method was proposed to evaluate particles packing efficiency. Based on symmetrical distribution hypothesis, the particles were separated to several narrow size grades to characterize the total system. Through changing upper interval grade void content, the evaluation index E of packing efficiency was calculated to evaluate the system packing efficiency. The availability of the method was tested via coal water slurry experiments. The results indicate that E is available to evaluate particles packing efficiency that is improved by increase of E and coal water slurry concentration. The best value of E is variable for different coal samples. When the parameter n in Rosin-Rammler model is between0.7 and 0.8, E gets its relatively high value, but some exception occurs possibly in multi-grading particles accumulation. The realizable concentration decreases when the sample is oxidized, even using a high E value. The expansion ratio coal water slurry prepared by the same coal sample is consistent.