Failure Analysis was Performed on Panel Coil Components in a Large Sterilizer. A failed specimen was examined, and it was determined that the cracking was due to fatigue. This observation led to the possibility that the failure was caused by vibration due to the rotating agitator. Bounding calculations indicated that the panels possessed natural frequencies between 8 and 100 Hz.
The forcing frequency of the six-bladed agitator was 15 Hz and vibration was therefore identified as the most likely culprit. Concurrently, finite element dynamic methods were used to established a natural frequency to account for the immersion of the panel in water, the frequency was close to 15 Hz. The two independent analyses both demonstrated the failure was induced by fatigue. Locations were provided for panel coil supports to eliminate the lower modes of vibration. O’Donnell engineers provided further guidance to assure the adequacy of welding processes and welding materials to achieve modifications that subsequently performed reliably in service.
O’Donnell Consulting Engineers Perform Failure Analysis and Design Modification for Clients in Industries including Energy, Manufacturing and Petrochemical.
Call Tom O’Donnell to Discuss Your Engineering Challenges (412) 835-5007
Related Projects
– Failure Analysis and Repair of an Overpressurized Storage Tank
– Failure Analysis and Redesign on a Cracked Thin Film Heat Exchanger (TFHE)
– Analysis of Defects in 304 Stainless Steel Mixer Blades
Similar Services
– Failure Analysis Services
– Vibration & Fatigue Analysis
– Engineering Troubleshooting
Resources
– Tom O’Donnell, PE
– Links to Engineering Resources
– Publications: Pressure Vessels, Welds and Other Applications, Fatigue, Elevated Temperature
