Root Cause Failure Analysis of Drag Chain Conveyor Failure in Pulverized Coal Injection (PCI) Mill.

Wednesday, September 30, 2026: 8:00 AM
306A (Québec City Convention Centre)
Mr. Kaushal Singh , Tata Steel, Jamshedpur, Jharkhand, India
Mr. Archit Mudugu , Tata Steel, Jamshedpur, Jharkhand, India
Mr. Susovan Das , Tata Steel, Jamshedpur, Jharkhand, India
Mr. Sudipta Ghosh , Tata Steel, Jamshedpur, India

Title: Root Cause Failure Analysis of Drag Chain Conveyor Failure in Pulverized Coal Injection (PCI) Mill.


Abstract:
A repeat failure of the drag chain conveyor in the Pulverized Coal Injection (PCI) mill caused significant plant downtime of approximately 60 hours and increased coke rate, which impacted hot metal production costs. The investigation identified several contributing factors: severe wear of the tail-end friction wheel, misalignment and levelling errors in the drive shaft, improper sprocket indexing, and the absence of shear pins in the drive arrangement. These conditions created excessive stresses on the chain links, leading to premature failure within 10 days of installation compared to the expected service life of 10 years.

Corrective actions included replacing the drive-end sprocket shaft, friction wheel, and damaged links, along with levelling corrections for installed components and Dye Penetration testing of all chain links to detect surface cracks. Preventive measures recommended include developing Standard Maintenance Practices (SMP), improving spare quality for the drive-end sprocket shaft with checks on tooth indexing and sprocket gauge, and ensuring strict adherence to shear pin usage. This case highlights the critical importance of alignment, component quality, and overload protection in maintaining drag chain conveyor reliability.

Keywords: Drag chain conveyor, misalignment, sprocket indexing, shear pin, PCI mill reliability.

 

See more of: Fatigue & Fracture I
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