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.

  • Supplemental Notes:
    • Presented at ASME-IEEE Joint Power Generation Conference, September 18-21, 1977.
  • Corporate Authors:

    American Society of Mechanical Engineers

    Two Park Avenue
    New York, NY  United States  10016-5990
  • Authors:
    • Ortolano, R J
    • La Rosa, J A
    • Welch, W P
  • Publication Date: 1977

Media Info

  • Features: References;
  • Pagination: 10 p.

Subject/Index Terms

Filing Info

  • 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