Case Study: Life cycle management, failure modes of axial induced draft fans using vibration analysis

Sunil Tiwari, Manager Engineering Reliability, OPGC


Four case studies on ID Fan failure
1.Ash induced erosion and Thinning of ID FAN impeller representing uniform erosion and subject to normal 1X vibration with increase in Horizontal amplitude.
2.Improper point load in the bearing assembly shaft and impeller leading to increase in the overall axial vibrations in short interval of 16 hrs.
3.High vibration and abnormal noise due to new bearing failure due to proper fittment.
4.Failure of axial fans due to improper stress relieving of fan blades and hub with no vibration signature in spectrum and vibration amplitudes.

Major learning in quality acceptance plan and capability deliver models for life cycle management of ID Fans
1. ID fan impellers should be uniform measured and impeller replacement in regular interval.
2. Quality acceptance  plan for the assembly of bearing assembly shaft .
3. Quality acceptance plan for fabrication of ID Fan impeller .

Application of predictive maintenance techniques
1. Remote sensing and local data collection in amplitude in velocity and displacement with trending in regular intervals.

Way forward and horizontal deployment in other equipments
1. Identify the failure modes of critical equipments in risk management exercise .
2. Quality control practices across all the life cycle of equipments and plant.

1.Failure modes and life cycle management of axial fans of size 5400 KW.
2. Vibration analysis techniques to understand the early detection of failure mechanism in fans.
3. Asset management strategies for large size power plants.


Bachelors in Mechanical engineering and proficiency in Physical asset management, predictive maintenance and preventive maintenance. 10 years + experience in establishing preventive and predictive maintenance programs, contract management and implementation in large size coal based power plant and non metal industry. Hands on experience in vibration analysis, analytical ferrography, motor current signature analysis of motors up to size 5400 KW, centrifugal and axial pumps, axial and radial fans, gearboxes and steam turbines.