Patent Number: 6,305,902

Title: Steam turbine stationary blade

Abstract: Precision cast hollow stationary blade used for final stage of steam turbine is improved to enhance drain recovery efficiency. Hollows (4, 5), sectioned by rib (6) to be independent of each other, are formed in stationary blade (1) passing therethrough from outer shroud 2 to inner shroud 3. A plurality of ventral slits (10 to 20) are provided on blade surface ventral side linearly with predetermined interval between the slits in two parallel rows. Dorsal slits (21 to 26) are also provided linearly with predetermined interval between the slits. Drain on blade surface enters the hollows (5, 4) through the ventral slits (10 to 20) and the dorsal slits (21 to 26), respectively, and flows out of the outer shroud (2) or the inner shroud (3) as drain (40 to 43) to be recovered. While prior art hollow is single hollow and drain entering the hollow through the dorsal slits flows out through the ventral slits or reverse case thereof occurs, the hollows (4, 5) of the present invention being sectioned by the rib (6), the drain is prevented from flowing out to the opposite side.

Inventors: Konishi; Tetsu (Takasago, JP), Magoshi; Ryotaro (Takasago, JP), Toda; Hideyuki (Takasago, JP), Matsuo; Takaaki (Takasago, JP), Watanabe; Eiichiro (Takasago, JP)

Assignee: Mitsubishi Heavy Industries, Ltd.

International Classification: F01D 25/00 (20060101); F01D 25/32 (20060101); F01D 005/14 ()

Expiration Date: 10/23/2018