Patent ID: 7186072

Claim:
A recirculation structure for a turbo-compressor, comprising: an annular chamber oriented concentrically with a compressor axis in an area of free blade ends of a rotating blade ring, an axial center of the annular chamber lying in front of an axial center of the free blade ends, said annular chamber radially bordering a contour of a main flow channel, and a multitude of guide vanes arranged in the annular chamber and distributed around its circumference, wherein the annular chamber permits flow to pass through circumferentially in at least one of forward and rear areas thereof, wherein the guide vanes are connected to at least one wall of the annular chamber and are free-standing, wherein tips of the guide vanes face toward the main flow channel, and are at least nearly aligned with the contour of the main flow channel, wherein the tips of the guide vanes axially overlap or axially border the area of the free blade ends, and wherein the circumferential flow passes through openings in forward areas, in rear areas, or in both forward and rear areas of the guide vanes.