【摘要】 测量了一台循环流化床锅炉宽筛分原煤和冷渣的颗粒形貌,研究了球形度、Zingg指数、分形分数的变化,关联了Wadell球形度和Krumbein球形度之间的换算关系。研究表明,宽筛分煤燃烧后的冷渣比原煤具有更强烈的非线性特征。采用当量体积直径与Wadell球形度和Krumbein球形度的关联都是集中到某一个区域范围的散点图;采用扁平度、伸长度和Zingg指数为指标的颗粒形貌分布,显示多数颗粒形貌以片状颗粒为主;采用分形维数进行的颗粒描述显示,大颗粒和小颗粒的分形维数不同,大小颗粒的分界点对原煤约为3.17 mm,冷渣约为3.06 mm。更多还原

【Abstract】 The morphology of raw coal and cold cinder particles sifted through a wide-mesh screen from a circulating fluidized bed boiler has been measured along with a study of the change in sphericity,Zingg exponent and fractal fraction.Correlated was the conversion relation between Wadell and Krumbein sphericity.The study shows that the cold cinder produced by the combustion of coal sifted through a wide-mesh screen has non-linear characteristics stronger than those of raw coal. If an equivalent volumetric diameter is employed,its correlation with Wadell and Krumbein sphericity has all been concentrated to a scattering point chart in a certain zone range.Morphological particle distribution in case of using flatness elongation and Zingg exponent to serve as indexes will exhibit a morphological appearance of a great majority of particles,in which flaky particles predominate.The description of particles by using fractal dimensions will show different fractal dimensions for large particles and small ones.The boundary dividing point of big and small particles is about 3.17 mm for raw coal and about 3.06 mm for cold cinder.更多还原