燃煤电厂中速磨煤机内矿物质累积迁移规律研究

Study of the law governing the cumulation and migration of minerals in medium-speed vertical-spindle pulverizer of power plant

在中速磨煤机运行过程中,分离器返料反复研磨会降低磨机处理能力、增加磨机能耗和设备磨损。返料中富集的矿物质在研磨成合格煤粉进入锅炉燃烧后会加剧大气污染物的排放。为明确矿物质在磨机内部各节点物料中的累积迁移规律,奠定矿物质在线或离线去除的工艺基础,选用高硫煤和褐煤为代表性煤样,利用自制辊磨机进行煤样的循环破碎试验,研究循环破碎中合格煤粉和循环负荷粒度组成、灰分及矿物质变化情况,揭示磨机中矿物质的累积及迁移规律。

In the process of operation of the vertical-spindle pulverizer, repeated grinding of circulating material from air classifier may cause reduction of treating capacity of pulverizer, increase of power consumption and wearing of equipment. Furthermore, combustion in boiler of enriched mineral matters in pulverized coal gives rise to more presence of air-polluting contaminants. In order to bring to light the law governing cumulation and migration of minerals at different nodes in mill, and hence find out basic processes for both online and offline removal of such minerals, cyclic milling test is conducted in an indigenous roller mill with high-sulfur and lignite coal samples, with an aim to explore the size distribution and variation of ash and mineral contents of puluverized coal and circulating load, and reveal the law of accumulation and migration of minerals in pulverizer.