| 摘要 |
PURPOSE:To realize full draining without lowering efficiency of turbine step, by arranging the downstream side end face of a nozzle diaphragm outer ring in the further downstream side of the front of a rotor blade and forming a draining hole in the downstream side of said outer ring. CONSTITUTION:The downstream side end face of a nozzle diaphragm outer ring 2 positioned in the outer peripheral part of the tip for a rotor blade 7 of the last step, is arranged in the further downstream side of the front face 7a of said rotor blade 7. Then a ring-shaped segment holder 9 is joined to the downstream side end face of said outer ring 2 by a bolt 11 through a washer 10 so as to form a collar-like draining hole 12 in the downstream side of said outer ring 2. Further, a ring-like leakage control ring 13 which sets an axial gap value (c) of the draining hole 12 is coaxially inserted in said hole. Thus, only draining can be well performed without wasteful discharge of steam from the front of the rotor blade 7, and besides erosion can be prevented without lowering efficiency of turbine step. |
