DEM模拟解析二元混合颗粒粒径偏析分布规律

颗粒粒径偏析分布是高炉炉顶布料过程中不可避免的现象,易造成炉喉处局部料层的空隙度降低和压差升高,影响煤气流的均匀分布,继而间接影响炉况的顺行。通过DEM离散单元法模拟研究二元混合颗粒的偏析分布规律,同时,提出一个偏析指数T,用以表征粒径偏析分布的相对程度。研究结果表明:同一T值图中,相邻区域颗粒的T值相差越大,则该区域颗粒的粒径偏析程度越大;不同T值图中,所有相邻T值之差的平均绝对值越大,则颗粒堆积整体粒径偏析程度越为严重。

Analysis on distribution law of particle size segregation ofbinary particle mixtures based on DEM

The distribution of particle size segregation is an inevitable phenomenon during the burden distribution process of blast furnace, which can easily lead to the decrease of porosity and the increase of pressure at the throat of the furnace top. As a result, it makes an indirect impact on the uniform distribution of gas flow, thus indirectly affecting the smooth operation of blast furnace. Based on DEM (discrete element method)simulation method, present work studies the segregation status of binary particle mixtures and proposes a segregation index T, which could be used to characterize the relative degree of particle size segregation distribution. The results show that: in the same T value graph, the greater of the difference of value T between the adjacent area is, the greater of the degree of particle size segregation of the above areas is; and in different T value graphs, the greater of the average of all the absolute difference of value T between adjacent areas is, the greater of the overall degree of particle size segregation is.