Bucket tip/collection slot combination for open-circuit liquid-cooled gas turbines

Claim 1

In a gas turbine wherein a turbine disk is mounted on a shaft rotatably supported in a casing, said turbine disk extending substantially perpendicular to the axis of said shaft and having turbine buckets and platform means affixed to the outer rim thereof, said buckets receiving a driving force from a hot motive fluid confined within said casing and moving in a direction generally parallel to said axis of said shaft and the driving force being transmitted to said shaft via said turbine disk, means located radially inward of said platform adjacent said turbine disk for introducing liquid coolant within said turbine in a radially outward direction into open-circuit distribution paths by which said coolant traverses surface area of said rim and said platform means, passes into cooling channels in said buckets and exits from said channels in a radially outward direction, the improvement comprising: a manifolding, discharge and collection system for the coolant fluid exiting from the coolant channels in the turbine buckets, said system consisting of 1. first and second interconnected manifolds located beneath the bucket surface near the tip of each bucket in flow communication with the discharge ends of the coolant channels, said first and second manifolds being located on the pressure and suction sides of said bucket, respectively, 2. a single opening through the blade structure interconnecting said first manifold and the region of hot motive fluid flow within the casing near the trailing edge of said bucket, each of said manifolds being separated from the tip of said bucket by a wall formed in the bucket structure on the radially outward side of said manifold and extending generally chordwise of said bucket whereby coolant discharged radially from said coolant channels is redirected as required to reach said opening, and 3. liquid collection means located in the casing wall closely adjacent said trailing edge in register with said opening whereby open-circuit flow conditions are maintained with coolant fluid being discharged radially from said coolant channels into said manifolds, redirected and discharged from said first manifold through said opening into the hot motive fluid flow with excess liquid being thrown into said collection means.