单颗粒煤岩冲击破碎能耗与粒度分布特性试验研究

Experimental study on energy consumption and particle size distribution of single particle coal under impact crushing

为研究原煤进入流化床锅炉前破碎的能量转化规律,在落锤冲击试验台上对淮北无烟煤和淮北烟煤进行单颗粒冲击破碎试验。分析了破碎能耗与原煤以及破碎产物粒度分布的关系,以及破碎产物的粒度分布特性。研究结果表明:随着破碎程度的加深,两种煤比冲击破碎能耗呈指数增大;煤岩颗粒的易碎性随着煤岩初始粒径的增大呈现先增大后减小的趋势;当破碎产物t10值相同时,存在一个最佳的初始原煤粒径,此时的比冲击能耗最小;同等条件下淮北烟煤较淮北无烟煤更容易破碎成细小颗粒;单颗粒冲击破碎产物的粒度分布符合tn曲线族规律,冲击功增大对破碎产物中等粗细颗粒的含量影响较为显著,对微小颗粒含量的影响不大。

In order to investigate the energy consumption of coal particles under crushing before being fed into fluidized bed,a drop weight apparatus was employed to crush Huaibei anthracite and Huaibei bitumite. The relationship between energy consumption and size distribution of original coal particles and crushing products were discussed. The results show that the specific impact energy increases as the degree of crushing becomes deeper. The friability of coal is firstly strengthened and then weakened as the increase of original coal particle size. There is an optimum size of original coal particle at which the specific impact energy reaches minimum when the t10 of product is the same. Huaibei bitumite is easier to be crushed into finer particles than Huaibei anthracite in the same conditions. Sahoo's tncurves can describe the particle size distribution of shattered materials well. The impact strength has a significant influence on the content of coarse particles of shattered materials,however little influence on the content of fine particles.