Steam turbine

A steam turbine where wet steam flows in a turbine stage in low-pressure,

• comprising:
• rotor blades implanted in a circumferential direction to a turbine rotor provided to penetrate in a casing;
• stationary blades provided at an immediate upstream side of the rotor blades in the circumferential direction, and making up a turbine stage together with the rotor blades;
• diaphragm outer rings provided inside the casing, each including an annular extending part surrounding a periphery of the rotor blades, and supporting the stationary blades from outside in a radial direction;
• diaphragm inner rings supporting the stationary blades from inside in the radial direction;
• an annular slit formed at an inner surface of the diaphragm outer ring between the stationary blades and the rotor blades along the circumferential direction;
• and
• communication holes provided in plural at an outer surface of the diaphragm outer ring along the circumferential direction, the communication holes communicating to the annular slit from an outer surface side of the diaphragm outer ring, the communication holes connecting to the annular slit directly, the communication holes communicating to a suction part sucking liquid via the annular slit, the communication holes inclining relative to a radial line extending from a center axis of the turbine rotor in the radial direction at a cross section perpendicular to the turbine rotor axis direction, the communication holes inclining toward a reverse direction to a turning direction of the wet steam passed through between the stationary blades.