Patent ID: 8801371

Claim:
A gas turbine, comprising: a rotor rotatable about a rotor axis; rotatable blades mounted on the rotor in circumferential rows; a stator with an inner casing and stationary blades mounted in circumferential rows axially adjacent to the rotatable blades, wherein the inner casing and the rotor define a flow channel with a flow channel wall, and wherein each rotatable blade includes a blade shroud having a fin extending into a circumferentially extending cavity of the inner casing; a cooling arrangement with openings for a cooling flow arranged in a wall of the circumferentially extending cavity in the inner casing, wherein the cooling arrangement includes a protrusion arranged on each rotatable blade shroud and extending away from a leading edge of the respective rotatable blade and into the circumferentially extending cavity of the inner casing, wherein the protrusion extends in a direction dividing a space of the circumferentially extending cavity into a first, radially outer space and a second, radially inner space, where the openings for the cooling flow are arranged within the radially outer space, wherein a direction of the flow channel wall forms a second angle with a line of sight extending from an outer tip of the protrusion of the shroud of the rotatable blade to a radially inner most point of the wall of the circumferentially extending cavity in the inner casing, where a wall of the cavity meets a trailing edge of the stationary blade adjacent to the rotatable blade, and where the second angle is substantially from 10° to 40°.