Patent ID: 6884021
Filing Date: 2005-04-26
Classification: F01D,F02C,F02K

Abstract:
1. A single cascade multistage turbine comprising: a single cascade of rotor vanes; two supply ducts for causing a working fluid to flow on one side of said rotor vanes to one part of the circumferential direction of said rotor vanes; one or more circulation ducts each having an exhaust duct member through which said working fluid that has passed through said rotor vanes is drained out, a return duct member to return said working fluid to the former side of said rotor vanes, and an inflow duct member connected to said return duct member, which supplies said working fluid to said rotor vanes at a slightly different position in the circumferential direction of said rotor vanes; two exhaust ports to discharge said working fluid that has returned through the last circulation duct of said circulation ducts and passed through said rotor vanes; wherein said two supply ducts are disposed at 180° intervals in the circumferential direction, and said two exhaust ports are positioned on the opposite side in substantially intermediate positions in the circumferential direction of said supply ducts, a plurality of said circulation ducts are disposed over the entire circumferential range of said rotor vanes, and said rotor vanes are attached to the tips of moving vanes, and said moving vanes are driven directly to rotate by said working fluid.