Patent ID: 6860718

Claim:
A geothermal turbine, comprising: a turbine casing; a turbine rotor shaft; a plurality of nozzle diaphragm outer rings fixed to the turbine casing; a plurality of nozzle diaphragm inner rings located radially inside the nozzle diaphragm outer rings; a plurality of nozzles placed between the nozzle diaphragm outer rings and the nozzle diaphragm inner rings, which form a steam passage; a plurality of rotor blades mounted on the turbine rotor shaft, which face the nozzles and form a blade cascade in a circumferential direction; a shroud arranged on tip of the rotor blade; an overhang attached to the nozzle diaphragm outer ring, which extends downstream of the nozzles and has an inner surface facing radially outside the shroud; and a plurality of sealing fins which protrude radially outward from the shroud and face the overhang, wherein at least a part of the inner surface of the overhang, including a flat part of the inner surface facing directly across from at least a part of the plurality of sealing fins with a gap, is coated or overlay welded with a protective material.