高水分褐煤流动性实验研究

Experimental Study on Fluidity of High Moisture Lignite

【目的】研究原煤中水分、粒径以及煤仓材质对原煤流动性的影响,找出造成原煤仓堵煤的主要原因。【方法】设计并搭建了原煤流动性实验装置,对不同水分、粒径的原煤进行流动性实验,并绘制流动特性图,得到各要素对原煤流动性的影响。【结果】原煤水分越大,流动特性图折线越靠右,下落质量越少,流动性越差,完全下落所需的旋转角度越大;煤下落的初始位置不同是由于不同粒径之间的静摩擦力不同导致其安息角不同。水分降低会使得摩擦力减小,下落质量增大;聚四氟乙烯材质的流动性折线位置靠前,底部摩擦系数小,同样角度下落质量更多,流动性增强。【结论】水分在原煤流动性中起关键作用,粒径对原煤流动性的影响微弱,粒径只有与水分共同作用才会对其流动性产生较大影响。材质对原煤流动性的影响也较大,但在水分偏低时可忽略其影响。

[Objecttives]The influence of moisture in raw coal,particle size and coal bunker material on the fluidity of raw coal was studied to find out the main reasons for coal clogging in raw coal bunkers.[Methods]A raw coal flowability experimental device was designed and built to conduct flowability experiments on raw coal with different moisture and particle sizes,and flow characteristics diagrams were drew to obtain the effects of various factors on raw coal flowability.[Results]The greater the moisture in the raw coal,the more right the broken line in the flow characteristic diagram is,the less the falling mass,the worse the mobility,and the greater the rotation angle required for complete falling.The difference in the initial position of coal falling is due to the difference in static friction between different particle sizes,resulting in different repose angles.At the same time,the decrease in moisture will reduce the friction force and increase the falling mass.The liquidity bend line of polytetrafluoroethylene material is located at the front,and the friction coefficient at the bottom is small.At the same angle,the mass drops more and the mobility is enhanced.[Conclusions]Moisture plays a key role in the fluidity of raw coal,the influence of particle size on the fluidity of raw coal is weak,and only the interaction with moisture can have a great influence on the fluidity of raw coal.Material also has a greater impact on the fluidity of raw coal,but when the moisture is low,the impact can be ignored.