粒径对飞灰比电阻及介电特性的影响

摘要

The resistivity and dielectric property of fly ash play an important role in enhancing the dust re-moval rate and fly ash recirculation rate.To focus on this,fly ash samples were collected from two domestic power plants and then sieved into different particle sizes.By using powder resistivity detector and vector network analyzer (VNA),the effects of fly ash particle size on its specific resistivity and dielectric property were studied.The results show that,for the fly ash with carbon,the resistivity and dielectric loss of the fly ash had no obvious changing rule with the particle size.While for the decarbonized fly ash,the specific re-sistivity decreased and the dielectric loss of fly ash increased when the particle size decreased.%飞灰的比电阻和介电损耗对提高电厂的除尘效率和飞灰的回收利用影响较大。通过采集国内2个电厂的飞灰样品，将其筛分成不同粒径范围的灰样，利用粉末电阻率测定仪和矢量网络分析仪(VNA)研究粒径对飞灰比电阻及其介电特性的影响。结果表明，去碳前飞灰的比电阻和介电损耗均随粒径变化无明显变化规律；去碳后飞灰的比电阻随着粒径的减小呈逐渐减小趋势，而其介电损耗却随着粒径的减小逐渐增大。