Steam turbine nozzle plate having 360 discharge

Abstract

An inner shell of a steam turbine has discrete arcuate steam outlet ports through an axial face. In axial opposition is a nozzle ring including a pair of nozzle ring segments joined at a horizontal midline. At the midline joint, split partitions are employed to provide a full 360° discharge through the nozzle ring. The split partitions are split in an axial direction to define discrete partition portions in each of the nozzle ring segments adjacent the midline joint.

What is claimed is:  
     
         1 . A nozzle plate for a turbine comprising: 
 nozzle plate segments forming an annular array of nozzles, each segment including inner and outer band portions and circumferentially spaced partitions extending between said inner and outer band portions, adjacent ends of said segments forming a joint therebetween;    at least one of said joints including a split partition with a first portion of the split partition forming part of an end of one segment and a second portion of the split partition forming part of an adjacent end of another segment.    
     
     
         2 . A nozzle plate according to  claim 1  including a port bridge disposed in front of said split partition.  
     
     
         3 . A nozzle plate according to  claim 1  wherein each of said segments subtends an arc of 180°, another of said joints between said segments including a second split partition with a first portion thereof forming part of an end of said one segment and a second portion thereof forming part of an adjacent end of said another segment.  
     
     
         4 . A nozzle plate according to  claim 3  including a port bridge disposed between said inner and outer bands in an upstream direction relative to said split partitions.  
     
     
         5 . A nozzle plate according to  claim 1  wherein the split partition is split in an axial direction.  
     
     
         6 . A nozzle plate according to  claim 1  wherein each of said segments subtends an arc of 180°, another of said joints between said segments including a second partition split in an axial direction with a first portion thereof forming part of an end of said one segment and a second portion thereof forming part of an adjacent end of said another segment, said split partitions being split in axial directions.  
     
     
         7 . A nozzle plate according to  claim 1  wherein each of said segments subtends an arc of 180°, another of said joints between said segments including a second partition split in an axial direction with a first portion thereof forming part of an end of said one segment and a second portion thereof forming part of an adjacent end of said another segment, including a port bridge disposed in front of each said split partition, and a weld buildup between a leading edge of each split partition and the port bridge.  
     
     
         8 . A steam turbine comprising: 
 an inner shell having an axial face and a plurality of axially opening arcuately shaped steam outlet ports about said face with bridging portions between said outlet ports, a pair of said bridging portions being located at a horizontal midline of the turbine;    a plurality of nozzle segments forming an annular array of nozzles in axial registration with said axial faces of said inner shell, each segment including inner and outer band portions and circumferentially spaced partitions extending between said inner and outer band portions, adjacent ends of said segments forming joints therebetween with a pair of said joints lying along said horizontal midline of the turbine;    the joints between said segments along said horizontal midline lying in axial registration with bridging portions of the inner shell at said horizontal midline, each joint including a split partition with a first portion of the split partition forming part of an end of one segment and a second portion of the split partition forming part of an end of the adjacent segment, thereby enabling steam flow through adjacent outlet ports on opposite sides of the horizontal midline to in part flow along opposite sides of said split partition.    
     
     
         9 . A turbine according to  claim 8  including a port bridge disposed in front of each said split partition.  
     
     
         10 . A turbine according to  claim 8  wherein each of said segments subtends an arc of 180°.  
     
     
         11 . A turbine according to  claim 8  including a port bridge disposed in front of each said split partition, and a weld buildup between a leading edge of each split partition and the port bridge.  
     
     
         12 . A turbine according to  claim 8  wherein each of said split partitions are split in an axial direction.  
     
     
         13 . A turbine according to  claim 12  including a port bridge disposed in front of each said split partition, and a weld buildup between a leading edge of each split partition and the port bridge.