Inlet casing for a turbine

A turbine comprising:

• a rotor comprising a shaft which extends along and rotates about a central axis, at least one rotor wheel extending radially outward from the shaft to a radially outermost periphery, and a plurality of buckets arrayed circumferentially around the rotor wheel at the radially outermost periphery;
• a housing surrounding at least a portion of the rotor;
• a stationary flowpath component located axially upstream of each of the rotor wheels;
• a plurality of nozzle vanes housed in the stationary flowpath component, the nozzle vanes being axially spaced upstream from the buckets of the rotor wheel and configured to direct fluid against an upstream side of the buckets to effect rotation of the rotor wheel;
• a plurality of inlet fingers formed in the housing, each of the inlet fingers having opposing first and second ends and defining a substantially straight passage between the first and second ends, wherein the second ends of each of the inlet fingers are positioned against an upstream side of a portion of the nozzle vanes, wherein the second ends of each of the inlet fingers are positioned side by side to extend substantially around the circumference of the stationary flowpath component adjacent the nozzle vanes, and wherein the arc length of each of the circumferential portions of the stationary flowpath component supplied by the second end of one of the inlet fingers is ninety degrees or less.

A turbine comprising:

• a shaft which extends along and rotates about a central axis;
• at least one rotor wheel mounted on and extending radially outward from the shaft to a radially outermost periphery;
• a plurality of buckets arrayed circumferentially around the rotor wheel at the radially outermost periphery;
• a housing defining an interior, the housing surrounding at least the rotor wheels;
• at least one stationary flowpath component upstream from the rotor wheel;
• plurality of nozzle vanes which are axially spaced from the buckets of the rotor wheel and are configured to direct fluid against an upstream side of the buckets and effect rotation of the rotor wheel, wherein each of the nozzle vanes is mounted in the stationary flowpath component to have an inlet angle of sixty degrees or more with respect to the central axis;
• an inlet casing coupled to the interior of the housing
• at least one inlet finger formed in the inlet casing, each of the inlet fingers having opposing first and second ends and defining a substantially straight passage between the first and second ends, wherein second end is positioned against an upstream side of the nozzle vanes in a circumferential portion of the stationary flowpath component.