| 摘要 |
PURPOSE:To prevent the joining part between a shround and the back of a blade from erosion due to impact of waterdrops by providing a notch at a special position on the steam inlet side of the shroud provided in continuity to the steam turbine blade and deflecting a flow of waterdrops radially outward. CONSTITUTION:A shroud 2 is united in one body with a steam turbine blade 1, while Stellite material 3 is welded to the back on the steam inlet side of the blade 1 to prevent erosion of said back due to impact of waterdrops. In this case, a notch 10 is provided in a position of the shroud 2 adjacent to the back 11 of a blade top part of the steam inlet side. Thus, the steam 6 flowing in along the back of the blade 1 dashes into the innermost part of the notch 10 and a part of the steam 6 is returned in the direction along the edge part 10a of the notch 10, a vortex 13 being generated in the notch 10. Then, a flow of waterdrops 8 is deflected due to the vortex 13. Since the greater part of the waterdrops is radially blown off along with the vortex 13, the expected purpose can be attained. |
