LONG ARC SHROUDING--A RELIABILITY IMPROVEMENT FOR UNTUNED STEAM TURBINE BLADING
A method is described for preventing fatigue failures due to resonance in untuned exhaust blading in variable-speed steam turbines. The method, which has proved highly successful in numerous practical applications, entails butt-welding the shrouds in the short-arc blade groups to form groups of substantially longer arc length. This can form part of the initial design or--and this is one of the chief attractions of the method--it can be applied to existing plant in the field without removing the turbine rotor from its bearings. Two variations of long-arc shrouds are mainly discussed, namely semi-continuous (180 deg.) shrouds and harmonic shrouds in which the group length is equal to one cycle of the sine wave of the excitation pattern.
- Presented at ASME-IEEE Joint Power Generation Conference, September 18-21, 1977.
American Society of Mechanical EngineersTwo Park Avenue
New York, NY USA 10016-5990
- Ortolano, R J
- La Rosa, J A
- Welch, W P
- Publication Date: 1977
- Features: References;
- Pagination: 10 p.
- TRT Terms: Blades (Machinery); Design; Failure; Resonance; Steam turbines
- Old TRIS Terms: Resonance phenomena; Steam turbine design
- Subject Areas: Design; Marine Transportation; Vehicles and Equipment;
- Accession Number: 00180034
- Record Type: Publication
- Source Agency: British Ship Research Association
- Report/Paper Numbers: Paper 77-JPGC-Pwr-12
- Files: TRIS
- Created Date: Sep 27 1978 12:00AM