Patent ID: 6558114
Filing Date: 2003-05-06
Classification: F01D

Abstract:
A gas turbine comprising:a turbine casing; a rotor mounted for rotation within the turbine casing and comprising a rotor shaft and at least first stage and second stage rotor discs axially displaced on the rotor shaft to form an interstage disc cavity, the first stage and second stage rotor discs each having a plurality of rotor blades extending radially outward into a main gas flow; a stator comprising at least one stator stage extending radially inward into the interstage disc cavity from the turbine casing toward the rotor shaft, the at least one stator stage having a plurality of stator vanes axially aligned with the rotor blades in the main gas flow and terminating radially inwardly with a seal assembly which seals against the rotor shaft, the at least one stator stage forming with the first stage rotor disc an annular subcavity within the interstage disc cavity, said at least one stator stage including bolts connecting the seal assembly to the stator vanes and having bolt heads projecting axially into the subcavity; a cooling air inlet introducing into the interstage disc cavity cooling air which passes radially outward through the interstage disc cavity including the subcavity and is discharged into the main gas flow; and a baffle extending from the seal assembly partially across the subcavity toward the first stage rotor disc dividing the subcavity into a radially inward region and a radially outward region, the baffle being configured and positioned to confine ingress from the main gas flow to the radially outward region, the baffle being positioned radially outward of the bolt heads so that the bolt heads are in the radially inward region of the subcavity and protected from the ingress from the main gas flow, said baffle extending axially at least about &frac13; but no more than about &frac23; across the subcavity.