煤粉颗粒静电生成的实验研究

Experimental investigation of electrostatic generation of coal granules

煤粉颗粒广泛应用于采矿、能源等气固两相传输行业中。在工作过程中,煤粉颗粒之间及颗粒与壁面之间的碰撞与摩擦会产生静电,若不及时放电,会在工作系统中逐渐积累,给安全生产带来很多问题,如煤粉颗粒结团、堵塞和爆炸等危害。此外,气固两相流中煤粉颗粒带电会导致一系列测量问题,严重影响测量精度,甚至损坏仪器等。基于已有单颗粒静电生成的测量实验系统,研究三角形煤粉颗粒的各个因素对静电生成的影响,对诸因素进行比较分析,发现颗粒的长宽比、面积、前冲角、相对湿度及表面粗糙度均对静电有较大的影响,总结煤粉单颗粒静电生成机理及影响因素。

Coal granules are widely used in gas-solid two-phase transmission industries,such as mining and energy. In the industrial process,electrostatics is generated by the collision and friction between the coal granule and between the granule and the wall surface. If it is not discharged in time,it will gradually accumulate in the working system,thereby causing many problems for the safety production,such as granule clustering,blocking,sparking,explosion,etc. In addition,the charged granules in the gas-solid two-phase flow cause a series of measurement problems,which seriously affect the measurement accuracy and even damage the instruments. The main task of this experiment is to establish a measurement experiment system for electrostatic generation of single coal granules,and to study the effects of the physical factors,sliding velocity,environmental relative humidity,surface roughness, and granular materials on the generation of electrostatics. After comparing and analyzing the data,we found that these factors have greater impacts on electrostatics,and a comparative analysis was conducted to summarize the mechanism of electrostatic generation of single granules and the influences of various factors.