Arcuate nozzle segment and related method of manufacture

Abstract

A method of manufacturing reaction nozzles for a turbine comprising (a) providing a piece of flat plate stock of predetermined size and thickness; and (b) machining the piece of flat plate stock to form a unitary, arcuate reaction nozzle segment including at least two adjacent nozzle airfoils.

1 . A method of manufacturing reaction nozzles for a turbine comprising: 
 (a) providing a piece of flat plate stock of predetermined size and thickness; and    (b) machining said piece of flat plate stock to form a unitary, arcuate reaction nozzle segment including at least two adjacent nozzle airfoils.    
   
   
       2 . The method of  claim 1  wherein said reaction nozzle segment also includes a common tip shroud cover and a common dovetail hook at opposite ends of, and spanning, said at least two adjacent nozzle airfoils.  
   
   
       3 . The method of  claim 1  wherein said flat plate stock is comprised of a stainless steel alloy.  
   
   
       4 . The method of  claim 3  wherein said stainless steel alloy comprises a 400 Series stainless steel with 12% chromium.  
   
   
       5 . The method of  claim 1  wherein each of said arcuate segments spans substantially 180°.  
   
   
       6 . The method of  claim 1  wherein each of said arcuate segments spans substantially 90°.  
   
   
       7 . A method of manufacturing reaction nozzles for a turbine comprising: 
 (a) providing a single piece of flat plate stock of predetermined size and thickness; and    (b) cutting said flat plate stock to form a 360° ring;    (c) cutting said 360° ring into two or more arcuate segments; and    (d) machining each of said segments to include a plurality of nozzle airfoils.    
   
   
       8 . The method of  claim 7  wherein, during step (d), each segment also includes an integral, common tip shroud cover and an integral, common dovetail component.  
   
   
       9 . The method of  claim 7  wherein steps (b) and (c) are carried out with wire EDM.  
   
   
       10 . The method of  claim 7  wherein, during step (c), said ring is cut into two 180° segments.  
   
   
       11 . The method of  claim 7  wherein, during step (c), said ring is cut into four 90° segments.  
   
   
       12 . The method of  claim 7  wherein said flat plat stock is comprised of a stainless steel alloy.  
   
   
       13 . The method of  claim 12  wherein said stainless steel alloy comprises a 400 Series stainless steel with 12% chromium.  
   
   
       14 . A reaction nozzle component for a steam turbine comprising a unitary arcuate segment formed to include a plurality of adjacent nozzle airfoils.  
   
   
       15 . The reaction nozzle component of  claim 14  wherein said plurality of nozzle airfoils extend radially between a common tip shroud and a common dovetail component.  
   
   
       16 . The reaction nozzle component of  claim 14  wherein each segment spans substantially 180°.  
   
   
       17 . The reaction nozzle component of  claim 14  wherein each segment spans substantially 90°.  
   
   
       18 . The reaction nozzle component of  claim 14  wherein said segment is composed of a stainless steel alloy.  
   
   
       19 . The method of  claim 18  wherein said stainless steel alloy comprises a 400 Series stainless steel with 12% chromium.  
   
   
       20 . The reaction nozzle of  claim 15  wherein said common dovetail component comprises a dovetail hook.  
   
   
       21 . The reaction nozzle of  claim 15  wherein said common dovetail component comprises a centerline support mechanism for a 180° arcuate segment.