Controlled flow runners for turbines

Abstract

This application provides controlled flow runners ( 130 ) for use with steam turbines. Example controlled flow runners ( 130 ) may include a tip, a blade ( 132 ) adjacent to the tip, the blade ( 132 ) having a top width ( 134 ), a middle width ( 136 ), and a bottom width ( 138 ), where the middle width ( 136 ) is less than the top width ( 134 ) and the bottom width ( 138 ), and a root adjacent to the blade ( 132 ).

1 - 14 . (canceled) 
     
     
         15 . A controlled flow runner for use with a steam turbine, the controlled flow runner comprising:
 a root;   a blade projecting radially outwardly from the root, the blade having a bottom width, a middle width, and a top width;   and a tip adjacent to the blade;   wherein the middle width is less than the top width and the bottom width.   
     
     
         16 . The controlled flow runner of  claim 15 , wherein a leading edge of the blade defines a linear edge; and wherein a trailing edge of the blade comprises an arcuate edge from the root to the tip. 
     
     
         17 . The controlled flow runner of  claim 16 , wherein the arcuate edge of the trailing edge defines a concave shape from the root to the Up. 
     
     
         18 . The controlled flow runner of  claim 16 , wherein a first center of gravity of the root is offset from a second center of gravity of the blade; and wherein the second center of gravity of the blade is offset from a third center of gravity of the tip. 
     
     
         19 . The controlled flow runner of  claim 16 , wherein the bottom width is greater than the top width. 
     
     
         20 . The controlled flow runner of  claim 19 , wherein the root is coupled to a disc; and wherein the bottom width is adjacent to the root. 
     
     
         21 . The controlled flow runner of  claim 15 , wherein the middle width is an axial width dimensioned to reduce profile losses. 
     
     
         22 . The controlled flow runner of  claim 15 , further comprising a tip shroud coupled to the tip, the top width being adjacent to the tip shroud. 
     
     
         23 . The controlled flow runner of  claim 15 . wherein the blade is positioned adjacent to a controlled flow guide, wherein the controlled flow runner is configured to reduce mixing losses. 
     
     
         24 . The controlled flow runner of  claim 15 , wherein a pitch distribution of the blade generates a controlled flow vortex distribution. 
     
     
         25 . The controlled flow runner of  claim 15 , wherein the Back Surface Deflection of the blade is greater than a threshold value. 
     
     
         26 . A steam turbine comprising:
 a disc;   a casing circumferentially surrounding the disc;   a controlled flow guide mounted in the casing;   a controlled flow runner coupled to the disc adjacent the controlled flow guide, the controlled flow runner comprising a root;   a blade projecting radially outwardly from the root, the blade having a bottom width, a middle width, and a top width; and   a tip adjacent to the blade;   wherein the middle width is less than the top width and the bottom width.   
     
     
         27 . The steam turbine of  claim 26 , wherein a leading edge of the blade defines a linear edge; and wherein a trailing edge of the blade comprises an arcuate edge from the root to the tip. 
     
     
         28 . The steam turbine of  claim 27 , wherein the arcuate edge of the trailing edge defines a concave shape from the root to the tip. 
     
     
         29 . The steam turbine of  claim 27 , wherein a first center of gravity of the root is offset from a second center of gravity of the blade; and wherein the second center of gravity of the blade is offset from a third center of gravity of the tip. 
     
     
         30 . The steam turbine of  claim 27 , wherein the bottom width is greater than the top width. 
     
     
         31 . The steam turbine of  claim 30 , wherein the root is coupled to a disc; and wherein the bottom width is adjacent to the root. 
     
     
         32 . The steam turbine of  claim 26 , wherein the middle width is an axial width dimensioned to reduce profile losses. 
     
     
         33 . The steam turbine of  claim 26 , further comprising a tip shroud coupled to the tip, the top width being adjacent to the tip shroud. 
     
     
         34 . The steam turbine of  claim 26 , wherein the blade is positioned adjacent to a controlled flow wide, wherein the controlled flow runner is configured to reduce mixing losses.