Patent ID: 7390160
Filing Date: 2008-06-24
Classification: F01D,F05D

Abstract:
1. An axial flow steam turbine assembly, comprising: a first turbine having a first rotor drum, a first turbine casing, a first steam outlet and a plurality of first reaction turbine stages, each first reaction turbine stage having an annular row of first static blades extending between a first outer static ring fixed to the first turbine casing and a first inner static ring, a first sealing device acting between the first inner static ring and the first rotor drum, and an annular row of first moving blades having first root portions held in first peripherally extending slots of the first rotor drum; and a second turbine having a second rotor drum, a second turbine casing, a second steam inlet communicating with the first steam outlet, and at least one modified turbine stage having an annular row of second static blades extending between a second outer static ring and a second inner static ring, an annular row of second moving blades having second root portions held in second peripherally extending slots of the second rotor drum, a second sealing device acting between the second inner static ring and the second rotor drum, the second outer static ring being axially located in a recess in the second turbine casing, wherein the second outer static ring has greater thermal inertia and greater stiffness than the second inner static ring and is capable of limited radial movement relative to the second turbine casing, and wherein one of the first and second turbines is a higher pressure turbine, and the other of the first and second turbines is a lower pressure turbine.