Root cause failure analysis of coal mill vertical shaft
2010 (English)In: Proceedings of the 1st international workshop and congress on eMaintenance, Luleå tekniska universitet, 2010, 176-181 p.Conference paper (Refereed)
A root cause failure analysis of coal mill vertical shaft used in thermal power plant has been carried out. The failed parts of the shaft showed the signature of fatigue failures. The fatigue cracks originated from the top edge of the keyway area, where the bowl is assembled. Operating conditions, material of the shaft and design of the shaft for strength are the possible causes for the fatigue failure. Due to some constrains the operating conditions cannot be changed. It is found after conducting experiments that the strength of the material used for the shaft is not uniform, however, the material change is beyond the scope of the plant. Therefore, the initial design of the shaft has been analyzed. It is found that the high stress concentration is at the top edge of the keyway, where the fatigue crack originates. The value of stress concentration can be reduced by changing the geometry of the keyway. Therefore, four cases of the change in keyway geometry has been studied using commercial software ANSYS. The result showed in one of the cases that the stress concentration reduces by 36% and it is implementable in plant location. The failure analysis results of coal mill vertical shaft used in thermal power plant as carried out in a case study, will be available to the designer and manufacturer, besides the users and the experts, through the e-Maintenance system.
Place, publisher, year, edition, pages
Luleå tekniska universitet, 2010. 176-181 p.
Research subject Operation and Maintenance
IdentifiersURN: urn:nbn:se:ltu:diva-35098Local ID: 97d049f0-aec3-11df-a707-000ea68e967bISBN: 978-91-7439-120-6 (PDF)OAI: oai:DiVA.org:ltu-35098DiVA: diva2:1008350
International Workshop and Congress on eMaintenance : 22/06/2010 - 24/06/2010
Godkänd; 2010; 20100823 (ysko)2016-09-302016-09-30Bibliographically approved