Failure Analysis of Pulverized Coal Injection (PCI) Mill Grinding Roller Bearing at Blast Furnace

• Published in: Journal of failure analysis and prevention Vol. 24; no. 5; pp. 2261 - 2266
• Main Authors: Jain, Aditya, Thirumurugan, T., Kumar, N. Rajesh, Das, Sandip, Solanki, Vikas
• Format: Journal Article
• Language: English
• Published: Materials Park Springer Nature B.V 2024
• Subjects: Assembly; Blast furnaces; Coal; Coal injection; Coke fired furnaces; Coke ovens; Coking; Cost analysis; Failure analysis; Hot blast; Integrated iron and steel plants; Plant layout; Production costs; Pulverized coal; Roller bearings
• ISSN: 1547-7029; 1864-1245
• DOI: 10.1007/s11668-024-01981-z

In an integrated steel plant, the pulverized coal injection (PCI) mill plays an important role in providing pulverized coal to the blast furnace. The main purpose of using PCI coal is to reduce the hot metal production cost through the utilization of non-coking coal and to extend the available coke oven life. Any unplanned outage of the PCI mill leads to increase in production cost. The three stationary grinding rollers are arranged equidistantly on the grinding plate. Each grinding roller is fixed to the pressure frame by means of a pressure yoke. Each grinding roller is borne by two roller bearings on the axle of the pressure yoke. The bearings are oil lubricated, and oil level cannot be checked in running condition due to design constraints. The bearing of new grinding roller assembly damaged within 1 service month. Bearing mode of failure was seizure, and it happened due to lack of oil. Therefore, root cause failure analysis has been carried out, and incorrect assembly was the responsible of this failure. Detailed investigation report is covered in this paper. The same type of failure can be avoided by implementing the recommendations which has been addressed in this paper.