煤粉的流动性测试及评价方法

Measurement of flowability of coal powders and research methods

采用休止角法、HR(Hausner ratio)法、Carr流动性指数法、Jenike法和质量流率法实验研究了不同粒径的羊肠湾煤粉、北宿煤粉和田坝煤粉的流动性,对5种方法进行了比较与分析。结果表明:煤粉粒径越小,流动性越差,当粒径小于约75μm时,改变煤粉粒径对流动性改善效果显著;相似粒径下3种煤粉流动性存在差异,北宿煤粉流动性最差;各种方法对煤粉流动性趋势关系的描述具有良好的一致性;在40kPa的预压缩应力下,煤粉流动指数值ffc超出了传统的ffc与流动性关系范围。

The flowability of Yangchangwan,Beisu,and Tianba coal powders with different particle sizes were investigated by using five methods,including angle of repose,Hausner ratio,Carr flow index,Jenike theory and mass flow rate.The methods were compared and analyzed systematically.Experimental results showed that the flowability of the coal powders could be improved obviously by increasing particle size,especially for those smaller than 75 μm approximately.Flowability of the three coal powders in similar sizes could be distinguished by angle of repose,Hausner ratio and Carr flow index,and Beisu coal behaved the poorest in flowability.The methods had a good agreement in describing the trend of flowability.However,at preconsolidation stress of 40 kPa,the flow index ffc was beyond its traditional relationship with flowability.