IFB Adopts ALERTech-IM to address High-Frequency Resonance & Repetitive Impeller Failure in Sealed Quench Furnace Recirculation
The manufacturing facility of IFB Industries Ltd. in Gangarampur in eastern India contributes significantly to its broad engineering portfolio.
Challenge
The site has eight operating furnaces which reported repetitive impeller blade joint cracking on its recirculation fan motors.
Operators detected the recirculation fan impeller failure only 2–7 days after an abnormal surge of noise and vibration.
In some instances the bearings on motors were replaced but led to no improvement.
Structural vibrations would lead to furnace shutdowns, resulting in reduced productivity, higher maintenance costs and an increase in unplanned downtime.
Recurring failures over the years had reduced the lifespan of the motors’ impellers to 1.5 years.
Solution
ALERTech-IM, based on MCSA technology, was installed on four of the eight operating furnaces to monitor the current spectrum signatures of their recirculation fan motors. The idea was to observe whether the motor current spectrum would detect abnormal signatures prior to the impeller failures.
The diagnostic findings of the current spectrum did present high frequency sidebands bearing high amplitudes correlating with the problematic recirculation fans. The findings signified systemic mechanical resonance phenomenon, caused by the matching frequencies between the fan vibration and the furnace’s structural natural frequency.
It was able to root out causes such as bearing damage, stator slot anomalies and eccentricity faults.
What’s Next
While the efficacy of ALERTech-IM diagnostics is still under observation, it has strengthened IFB’s early fault prediction capability. The Gangarampur plant is now able to anticipate failure before crack propagation peaks.
Future steps include standardizing high-frequency monitoring for all future furnaces.
Engineering Pathways Recommended
An immediate action to prevent damage is to redesign the impeller by improving its construction material and manufacturing dimensions, as well as modifying the coupling design from single bolt to multi-bolt.
A long-term solution includes structural reinforcement of the recirculation fan mounting to eliminate the root cause of matching high-frequency resonance.