燃煤可吸入颗粒物磁力聚并脱除特性的实验研究  

Experimental Study on Aggregation and Precipitation Characteristics,with Magnetic Seeding,of Inhalable Particulates from Coal Combustion

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：《动力工程》2007年第4期611-615,共5页Power Engineering

基　　金：国家重点基础研究发展计划资助项目(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：采用Fe3O4和Fe2O3 2种磁性物质在均匀磁场中对东胜烟煤燃烧产生的粒径0．023～9．318μm范围内的飞灰粒子进行了聚并实验，研究了飞灰粒子聚并的动力学特征以及不同磁性物质对飞灰粒子聚并的差异。实验结果表明：Fe3O4对飞灰粒子的聚并脱除效率高于Fe2O3，且聚并脱除后粒子中间直径高于Fe2O3；中间粒径粒子的脱除效率高于小粒子和大粒子；随磁感应强度、磁性物质添加比例、气流平均速度、粒子在磁场中停留时间等的增加，飞灰粒子的脱除效率提高，中间粒子直径减小，且小粒子脱除效率的增幅高于大粒子；当粒子达到饱和磁化时，磁感应强度的增强对聚并无影响。数值模拟结果表明，在飞灰粒子质量浓度为40g／m^3时，Fe3O4和Fe2O3对飞灰粒子的脱除效率分别为84％和62％，粒子中间直径从初始的0．151μm分别降低到0．098μm和0．085μm。Experiments on aggregation of fly-ash particulates, in the size range of 0. 023 - 9. 318μm, originated from the combustion of Dongsheng bituminous coal, were conducted in a uniform magnetic field, seeded with magnetic Fe2O3 and Fe3O4, including studies on the dynamit behavior, of magnetism influenced aggregating fly ash particulates, as well as on the influence, of different magnetic seeding matter, on the particulates＇ aggregative behavior. Experimental results show that the dust aggregation and removal efficiency of magnetic Fe3O4 seeds not only exceed that of Fe2O3, but the number, of aggregated medial sized particles, is also larger; the removal efficiency of medial sized particles is higher than that of the smaller as well as the larger ones; the dust particle＇ s removal efficiency increases with increasing magnetic flux density, propotion of magnetic seeds added, mean flow velocity, and also with lingering time of the particles in the magnetic field. Simultaneously, the number of medial sized particles decreases, and the removal efficiency of smaller particles increases quicker than that of the larger ones. But , as soon as the particles have got megnetically satureted, further increasing flux density doesn＇t effect aggregation any more. Numerical simulation results indicate that with a dust particle mass concentration of 40 g·m^-3 the deposition efficiency obtainable is 84 % and 62 % respectively for Fe3O4 and Fe2O3 seeding, and the medial particle size is reduced from the original 0. 151μm to 0. 098μm and 0. 085 μm respectively.

关 键 词：环境工程学 燃煤 可吸入颗粒物 导磁物质 聚并 

分 类 号：X513[环境科学与工程—环境工程]