Failure analysis of Rocker liner used as a charging system of blast furnace

摘要

The Rocker liner is a fundamentally important charging unit of blast-furnace operation. In the modern day, blast furnace rocker liner is used as a path-way of charge. In bell-less top charging system of blast furnace, the rocker liner is used for carrying the charge (i.e., raw material, burden etc.) to the related hopper through tilting motion and it acts accordingly. The tilting Rocker liner is situated in the assembly of two hoppers from where the top charging is done. The charge is fed to the hopper with the help of the liner. The liner assembly is tilted and the charge is fed to a hopper and other in course of operation (Fig. 1). The working temperature of the liner generally rises to 20 °C–40 °C above the ambient temperature during the operation. During the operation those liners undergo wear during carrying of charges to the hopper. The components get worn out within 8 months of service, whereas the expected life is 24 months. In-depth investigation of a failed rocker liner has been carried out and the root cause has been identified. Material of the liner should be such that it should be withstand wear and impact during feeding of the material in blast furnace. Frequent failure of the component leads to interruption in production and therefore, it is important to achieve higher life for the component.