梯度磁场中燃煤PM_(10)聚并实验  

Experimental study on aggregation of coal-fired PM_(10) in gradient magnetic field

作　　者：李永旺[1] 吴新[1] 赵长遂[1] 鲁端峰[1] 韩松[1] 

机构地区：[1]东南大学洁净煤发电及燃烧技术教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2007年第1期84-88,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家重点基础研究发展计划(973计划)资助项目(2002CB211600);江苏省高等学校研究生创新计划资助项目;东南大学优秀博士学位论文基金资助项目

摘　　要：在永磁环梯度磁场中对0.023-9.318μm粒径范围内东胜煤灰和大同煤灰进行了聚并实验研究.采用流化床气溶胶发生器对飞灰进行气溶胶化,采用低压电称冲击器在线测量聚并前后飞灰粒子的数目浓度.结果表明:在相同条件下,磁性较强的东胜煤灰粒子的聚并脱除效率高于磁性较弱的大同煤灰粒子的聚并脱除效率;增大飞灰粒子质量浓度或延长粒子的聚并时间,飞灰粒子的分级聚并脱除效率和整体聚并脱除效率提高,且东胜煤灰比大同煤灰整体脱除效率提高更为迅速;提高气流平均速度,飞灰粒子的分级聚并脱除效率和整体聚并脱除效率降低;中间粒径粒子的聚并脱除效率高于小粒子和大粒子的聚并脱除效率;随整体聚并脱除效率的提高,分级聚并脱除效率最大值对应的粒径减小,粒子数目中位直径减小.Aggregation experiments of fly ash particles in the size range of 0. 023 to 9.318 μm from Dongsheng and Datong coal combustion were conducted in a gradient magnetic field formed by permanent magnet rings. The fluidized bed aerosol generator was used to aerosol the fly ash, and the Electrical Low Pressure was used to measure the particle number concentration before and after particle aggregation. The results show that the removal efficiency of particles with higher magnetization from Dongsheng coal is higher than that of particles with lower magnetization from Datong coal combustion under the same condition. The grade and overall particle removal efficiencies can be enhanced by raising the particle mass concentration and the particle aggregation time, which is even more remarkable in particles from Dongsheng coal combustion than in particles from Datong coal combustion. When the average gas velocity is increased, the grade and overall removal efficiency decrease. The removal efficiencies of mid-sized particles are higher than those of smaller and bigger ones. With the increase of overall particle removal efficiency, both the particle size corresponding to the highest grade removal efficiency and particle number median diameter decrease.

关 键 词：燃煤PM10 磁聚并 永磁环 梯度磁场 

分 类 号：X513[环境科学与工程—环境工程]