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US5326221A Expired / Lapsed US ⏱️ 0.0 years remaining

Over-cambered stage design for steam turbines

Assignee: General Electric Co
•
Filing: 1993-08-27
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Granted: 1994-07-05
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Expires: 2013-08-27
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Abstract

Abstract Steam turbine nozzle blades and buckets are profiled in accordance with Tables I and II or multiples of the X,Y and R coordinates of the charts. The profiles of the nozzle blades impose a parabolic flow distribution at the throat and the buckets accommodate the incoming flow. The nozzle blades and buckets are over-cambered at their roots and tips to constrict flow from the roots and tips into the mid-regions of the blades and buckets. Improved aerodynamic efficiencies are obtained by directing the flow away from the end walls of the blades and buckets toward the efficient mid-region of the blades and buckets whereby flow velocity and angle leaving the nozzle has a non-linear distribution and the bucket velocity leaving angles are similarly non-linear.

Inventors

  • 👤 Joseph W. Amyot
  • 👤 Stephen G. Ruggles
  • 👤 Philip F. Berrahou
  • 👤 Robert J. Orlando

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 09:03
CPC Classifications
F; F01; F01D; F01D1/00; F01D5/00; F01D5/12; F01D5/14; F01D5/141; F01D5/145; F05; F05D; F05D2240/00; F05D2240/20; F05D2240/30; F05D2240/301

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 116 words
A nozzle for a steam turbine having a pair of adjacent blades having leading and trailing edges, blade bodies therebetween, and root and tip portions with a mid-region therebetween, said adjacent blades defining a throat therebetween measured by a series of straight lines extending from the trailing edges of a blade to the closest adjacent surface along the body of the adjacent blade and defining a pitch in the circumferential spacing between blades, the ratios of the throat to the pitch at successive profiles along said blades increasing from the root portions toward a mid-blade region and then decreasing from the mid-blade region to the tip portion, the blades being one of nozzle or bucket blades.
Claim 2
Dependent Claim 116 words
A nozzle for a steam turbine having a pair of adjacent blades having leading and trailing edges, blade bodies therebetween, and root and tip portions with a mid-region therebetween, said adjacent blades defining a throat therebetween measured by a series of straight lines extending from the trailing edges of a blade to the closest adjacent surface along the body of the adjacent blade and defining a pitch in the circumferential spacing between blades, the ratios of the throat to the pitch at successive profiles along said blades increasing from the root portions toward a mid-blade region and then decreasing from the mid-blade region to the tip portion, the blades being one of nozzle or bucket blades.
Claim 3
Dependent Claim 15 words
A nozzle for a steam turbine having a blade profile in accordance with Table I.
Claim 4
Dependent Claim 15 words
A nozzle for a steam turbine having a blade profile in accordance with Table I.
Claim 5
Dependent Claim 35 words
A stage for a steam turbine having a plurality of nozzles each having a blade profile according to claim 2 and a plurality of buckets each having a bucket profile in accordance with Table II.
Claim 6
Dependent Claim 27 words
A nozzle for a steam turbine having nozzle blade profiles in accordance with Table I scaled by multiplying X,Y and R coordinates thereof by a predetermined number.
Claim 7
Dependent Claim 27 words
A nozzle for a steam turbine having nozzle blade profiles in accordance with Table I scaled by multiplying X,Y and R coordinates thereof by a predetermined number.
Claim 8
Dependent Claim 47 words
A stage for a steam turbine having a plurality of nozzles each having a blade profile according to claim 4 and a plurality of buckets each having a bucket profile in accordance with Table II scaled by multiplying X,Y and R coordinates thereof by said predetermined number.
Claim 9
Dependent Claim 15 words
A bucket for a steam turbine having a bucket profile in accordance with Table II.
Claim 10
Dependent Claim 15 words
A bucket for a steam turbine having a bucket profile in accordance with Table II.
Claim 11
Dependent Claim 35 words
A bucket for a steam turbine having a bucket profile in accordance with Table II scaled by multiplying X,Y and R coordinates thereof by a predetermined number. blades being one of nozzle or bucket blades.
Claim 12
Dependent Claim 35 words
A bucket for a steam turbine having a bucket profile in accordance with Table II scaled by multiplying X,Y and R coordinates thereof by a predetermined number. blades being one of nozzle or bucket blades.

References Cited (Backward Citations)

US2795373A Cited
US3953148A Cited
US4208167A Cited
US4616975A Cited
US4696621A Cited
US4741667A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-07-04 1998-01-03 1998-07-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-07-04 2002-01-03 2002-07-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-07-04 2006-01-03 2006-07-05 $7700.00 Window Closed / Lapsed

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