Patent ID: 8678301

Claim:
A swirling device for injecting a medium into a turbine, comprising: a center axis; a central passage in an axial direction along the center axis; an outer perimeter; and a ground plate with a face surface in which a plurality of grooves are milled to form a first duct and a second duct, wherein the first duct and the second duct are adapted for guiding the medium from a region surrounding the outer perimeter to the central passage, wherein the first duct comprises a first ground area extending from a radially inner end to a radially outer end of the first duct, the first ground area defining a lying entirely within a first plane that is perpendicular to the center axis, wherein the second duct comprises a second ground area extending from a radially inner end to a radially outer end of the second duct, the second ground area lying entirely within a second plane that is perpendicular to the center axis, wherein the first duct further comprises a first depth in the axial direction and the second duct further comprises a second depth in the axial direction, wherein the first depth is measured from the first ground area to an upper end of the first duct and the second depth is measured from the second ground area to an upper end of the second duct, wherein the first depth and the second depth are different from each other, and wherein the first depth and second depth are provided by a different material thickness of the ground plate.