Patent ID: 8251643

Claim:
A steam turbine comprising: a rotor including: a first rotor section having a first axial end face with a first flow passage and a separate second flow passage; a second rotor section having a second axial end face with a first flow passage and a separate second flow passage, the second rotor section disposed axially adjacent and circumferentially rotated to the first rotor section so that the second axial end face faces the first axial end face so that each of the first flow passages in the two rotor sections line up to make a first continuous passage and each of the second flow passages in the two rotor sections line up to make a second continuous passage, wherein the first continuous passage and the second continuous passage are separated at an interface of the two rotor sections, and wherein a flow from the first continuous passage does not interact in the rotor with a flow from the second continuous passage; and a passage system formed in the rotor, the passage system including: a first inlet flow passage to an interface, the first inlet flow passage configured to receive steam from a first region of an outer surface of the rotor; a first outlet flow passage from the interface, the first outlet flow passage configured to pass steam to a second region of the rotor; a second inlet flow passage to the interface, the second inlet flow passage configured to receive steam from a third region of the outer surface of the rotor, and a second outlet flow passage from the interface, the second outlet flow passage configured to pass steam to a fourth region of the rotor.