Steam turbine nozzle segment having arcuate interface

Abstract

Steam turbine nozzle segments with conical interfaces are disclosed. In one embodiment a steam turbine static nozzle blade includes: an airfoil; an inner sidewall integral with a first side of the airfoil; and an outer sidewall integral with a second side of the airfoil; the inner sidewall and the outer sidewall each including: a pressure side having an arcuate concave surface extending substantially an entire length of the sidewall; and a suction side having an arcuate convex surface extending substantially the entire length of the sidewall.

1 . A steam turbine static nozzle blade comprising:
 an airfoil;   an inner sidewall integral with a first side of the airfoil; and   an outer sidewall integral with a second side of the airfoil;   the inner sidewall and the outer sidewall each including:
 a pressure side having an arcuate concave surface extending substantially an entire length of the sidewall; and 
 a suction side having an arcuate convex surface extending substantially the entire length of the sidewall. 
   
     
     
         2 . The static nozzle blade of  claim 1 , wherein the arcuate concave surface of the inner sidewall and the arcuate convex surface of the inner sidewall have a substantially equal arc radius. 
     
     
         3 . The static nozzle blade of  claim 2 , wherein the arcuate concave surface of the outer sidewall and the arcuate convex surface of the outer sidewall have a substantially equal arc radius. 
     
     
         4 . The static nozzle blade of  claim 3 , wherein the arcuate concave surface of the inner sidewall and the arcuate concave surface of the outer sidewall complement the arcuate convex surface of the inner sidewall and the arcuate convex surface of the outer sidewall, respectively. 
     
     
         5 . The static nozzle blade of  claim 1 , wherein the arcuate concave surface of the inner sidewall and the arcuate convex surface of the inner sidewall have a substantially equal arc length. 
     
     
         6 . The static nozzle blade of  claim 1 , wherein the arcuate concave surface of the outer sidewall and the arcuate convex surface of the outer sidewall have a substantially equal arc length. 
     
     
         7 . A steam turbine diaphragm assembly comprising:
 an outer diaphragm ring;   an inner diaphragm ring;   an annulus of static nozzle blades between the inner diaphragm ring and the outer diaphragm ring, each static nozzle blade comprising:
 an airfoil; 
 an inner sidewall integral with a first side of the airfoil; and 
 an outer sidewall integral with a second side of the airfoil; 
 the inner sidewall and the outer sidewall each including:
 a pressure side having an arcuate concave surface extending substantially an entire length of the sidewall; and 
 a trailing surface having an arcuate convex surface extending substantially the entire length of the sidewall; 
 
   wherein at least one of the static nozzle blades is demountably attached to a second one of the static nozzle blades.   
     
     
         8 . The steam turbine diaphragm assembly of  claim 7 , wherein the arcuate concave surface of the inner sidewall and the arcuate convex surface of the inner sidewall have a substantially equal arc radius. 
     
     
         9 . The turbine diaphragm assembly of  claim 8 , wherein the arcuate concave surface of the outer sidewall and the arcuate convex surface of the outer sidewall have a substantially equal arc radius. 
     
     
         10 . The steam turbine diaphragm assembly of  claim 9 , wherein the arcuate concave surface of the inner sidewall and the arcuate concave surface of the outer sidewall of a first one of the static nozzle blades complement the arcuate convex surface of the inner sidewall and the arcuate convex surface of the outer sidewall, respectively, of a second one of the static nozzle blades. 
     
     
         11 . The steam turbine diaphragm assembly of  claim 10 , further comprising a plurality of removable weld joints, each removable weld joint substantially removably affixing one of the static nozzle blades to one of the outer diaphragm ring or the inner diaphragm ring. 
     
     
         12 . The steam turbine diaphragm assembly of  claim 11 , wherein the at least one of the static nozzle blades is demountably attached to the second one of the static nozzle blades by at least one of the removable weld joints. 
     
     
         13 . The steam turbine diaphragm assembly of  claim 12 , wherein the at least one of the removable weld joints demountably attaches the at least one of the static nozzle blades to the second one of the static nozzle blades in an axial direction. 
     
     
         14 . A steam turbine diaphragm assembly comprising:
 an outer diaphragm ring;   an inner diaphragm ring;   an annulus of static nozzle blades between the inner diaphragm ring and the outer diaphragm ring, each static nozzle blade comprising:
 an airfoil; 
 an inner sidewall integral with a first side of the airfoil; and 
 an outer sidewall integral with a second side of the airfoil; 
 the inner sidewall and the outer sidewall each including:
 a pressure side having an arcuate concave surface extending substantially an entire length of the sidewall; and 
 a suction side having an arcuate convex surface extending substantially the entire length of the sidewall, wherein at least one of the static nozzle blades is demountably attached to a second one of the static nozzle blades in an axial direction; and 
 
   a plurality of pairs of removable weld joints, each pair of removable weld joints substantially removably affixing one of the static nozzle blades to one of the outer diaphragm ring or the inner diaphragm ring.   
     
     
         15 . The steam turbine diaphragm assembly of  claim 14 , wherein the arcuate concave surface of the inner sidewall and the arcuate convex surface of the inner sidewall have a substantially equal arc radius. 
     
     
         16 . The steam turbine diaphragm assembly of  claim 15 , wherein the arcuate concave surface of the outer sidewall and the arcuate convex surface of the outer sidewall have a substantially equal arc radius. 
     
     
         17 . The steam turbine diaphragm assembly of  claim 15 , wherein the arcuate concave surface of the inner sidewall and the arcuate concave surface of the outer sidewall of a first one of the static nozzle blades complement the arcuate convex surface of the inner sidewall and the arcuate convex surface of the outer sidewall, respectively, of a second one of the static nozzle blades. 
     
     
         18 . The steam turbine diaphragm assembly of  claim 14 , wherein each pair of removable weld joints substantially maintains an axial position of the removably affixed static nozzle blade. 
     
     
         19 . The steam turbine diaphragm assembly of  claim 14 , wherein the arcuate concave surface of the inner sidewall and the arcuate convex surface of the inner sidewall have a substantially equal arc length; and wherein the arcuate concave surface of the outer sidewall and the arcuate convex surface of the outer sidewall have a substantially equal arc length. 
     
     
         20 . The steam turbine diaphragm assembly of  claim 14 , wherein the removably affixed static nozzle blade is substantially affixed to the turbine diaphragm assembly by only the pair of removable weld joints.