Abstract: Experiments were conducted to investigate the electrostatic characteristics of anthracite and biomass powders in hopper. The effects of different operating parameters and material properties,in terms of the fluidizing time,fluidizing gas velocity,material type,particle size,the moisture content,on particle charging were examined with particle charge-to-mass measured by Faraday cup. And the fitting analysis on the various factors affecting the electrostatic was implemented. The results indicated that under the same experimental conditions,ratios of powders charge to mass increased as the fluidizing time went on. Charge saturation was attained for fluidization time greater than 90min. Biomass powders were always charged positively,whereas anthracite became negatively charged. As superficial velocity increased with stronger collision,the charge density of powders increased as well. The ratios of charge to mass of small size fine anthracite particles were larger than that of the big size fine anthracite particles with the same superficial velocity. The ratios of biomass powders charge to mass decreased significantly with the increase in the moisture content.

Key words: pneumatic conveying, electrostatic characteristics, powders

摘要： 在料罐静电测量试验装置中，对无烟煤和生物质进行静电特性研究。通过改变流化时间、流化风速等操作参数，以及粉体种类、粉体粒径、含水率等物性参数，用法拉第筒测得粉体荷质比，对料罐内粉体的静电量变化规律进行了研究，并对影响静电量变化的各因素进行了拟合分析。结果表明：在相同的试验条件下，随着流化时间的延长，物料的荷质比增大，当颗粒流化达到90min后，料罐内静电水平达到饱和状态；且生物质带正电，煤粉带负电；随着流化风速的增大，粉体间碰撞程度剧烈，粉体的荷质比增大；流化数相同的情况下，同种粉体颗粒粒径越小，荷质比越大。小粒径无烟煤的荷质比要明显大于大粒径无烟煤的荷质比；保持相同的流化条件，生物质外水含量越高，生物质的荷质比越小。

关键词: 气力输送, 静电特性, 粉体