Failure Analysis of a Polymer Centrifugal Impeller

An other new case study of failure analysis had been published in october 2015 in Case Studies in Engineering Failure Analysis.

A failure analysis investigation was performed on a fractured polymer impeller used in a respiratory blower. A radial split down the impeller center was observed, with symmetric fracture faces about the impeller bore. The brittle fracture morphology and defects within the impeller bore suggest that premature failure occurred because of multiple interacting factors including: intermittently high centrifugal velocities, imbalance bore and shaft conditions, defects within the bore caused by machining, and stress concentrations along the circumference of the impeller lip.

Read more at : Failure Analysis of a Polymer Centrifugal Impeller.

Failure analysis of a pelton impeller

A new topic on « http://www.sciencedirect.com/« .This paper, published in « Engineering Failure Analysis« , presents the analysis of a 16-bucket Pelton impeller from a hydroelectric plant in Colombia, a plant with two turbo generators with a nominal capacity of 2.33 MW each. Multiple cracks were detected one year subsequent to geometry reconstruction welding repair.

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Failure analysis of an MVR mechanical vapor recompressor Impeller

This article, published in  » Engeeniring Failure Analysis » of september 2010, describes the root cause failure analysis of a mechanical vapor recompressor (MVR) impeller used in a dairy processing plant. A detailed investigation was commissioned to determine the source of the oscillatory stresses that must have been present to cause fatigue. A vibration analysis indicated large torsional oscillatory stresses, leading to fatigue, were induced by excitation of the 1st and 2nd torsional vibration modes of the MVR impeller and motor system. The excitation was induced by the control system for the motor variable speed drive (VSD).

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