流化床煤焦混烧飞灰富集污染物的研究

Enrichment of heavy metals and organic pollutants in fly ash emitted from CFB during the combustion of coal blended with petroleum coke

针对310t.h-1煤焦混烧循环流化床锅炉,研究了不同工况下飞灰的粒径分布、孔隙结构及重金属、有机物的富集规律.结果表明,煤焦混烧情况下只有不到30%的飞灰粒径大于70μm.随着供氧量的增加、负荷降低、Ca/S比增大,小颗粒飞灰的体积分数增大.不同重金属的转移特性不同,锅炉负荷对重金属分布影响较大.飞灰中3环、4环多环芳烃含量较大,不同因素对各环数多环芳烃分布的影响不同.

The size distribution,pore structure,trace heavy metals and organic pollutants contained in fly ash produced under different combustion conditions were studied using a 310 t · h^-1 circulating fluidized bed（CFB）boiler during the combustion of coal blended with petroleum coke.The results demonstrated that the fly ash which was larger than 70 μm is less than 30% during the combustion of coal blended with petroleum coke.With increased O2,Ca/S ratio and decreased boiler load,the number of small particles increased.Different heavy metals had different migration characteristics and boiler load had a large influence on the distribution of heavy metals.The PAHs in the fly ash were dominated by three and four ring structures.Different factors had different influences on different ring PAHs.