高炉煤粉喷枪破损机理分析

高炉喷煤是现代高炉冶炼的一项重大技术革命,煤粉喷枪寿命直接影响喷煤操作与高炉正常生产,因此探索喷枪破损机理、研制长寿命喷枪成为高炉喷煤技术的重要课题。作者对某高炉实用喷枪进行跟踪监测,在正常工况下,材质为1Cr18Ni9Ti的喷煤枪平均寿命为32天。失效原因为表面氧化和煤粉流冲蚀磨损所致。本文从反应热力学分析了喷枪外表面氧化损坏机理,并由微切削理论解释了喷枪内壁出现沟状磨损痕迹及气固两相流动导致喷枪下半部分先磨损破口的原因。

THE FAILURE MECHANISM OF COAL LANCE IN BLAST FURNACE

Pulverized Coal Injection(PCI)is a key technology in modern ironmaking by blast furnace and the life of injection lance has a great influence on PCI operation and on normal running of blast furnace.For these reasons,it is important to research the failure mechanism of injection lance and to prolong its service life.Through monitoring some lances used in a blast furnace,it is found that the average service life of the lances made of 1Cr18Ni9Ti is about 32 days under normal blast furnace operating conditions.The main reasons for failure of the lances are their outer surface oxidation and the inner surface erosion.The failure mechanism of outer surface oxidation is further analyzed based on reaction thermodynamics,and it is explained by microcut theory and gas-particle flow that how the ditch-shaped crack forms on inner surface and why the underside of injection lance is abraded firstly.