Abstract: A method for cooling the flow in radial gaps formed between rotors and stators of turbomachines, which method is improved with regard to its cooling effect. In addition, a simple, cost-effective and robust arrangement for realizing the method is to be specified. According to the invention, this is achieved in that a first cooling fluid is admitted to a stator part adjacent to the radial gap and a second, gaseous cooling fluid is introduced into the radial gap. To this end, either at least one recess is formed in the interior of the stator part adjacent to the radial gap or at least one cavity is arranged at the stator part. The recess or the cavity is connected to both a feed line and a discharge line for the first cooling fluid. In addition, at least one feed passage as well as a discharge device for the second cooling fluid are arranged at the radial gap.

Abstract: A method of cooling the flow in radial gaps formed between rotors and stators turbo machines is provided. The method includes the step of using water as a cooling fluid for the stator part adjacent to the radial gap. To this end, either at least one recess is formed in the interior of the stator part adjacent to the radial gap or at least one cavity is arranged at the stator part. The recess or the cavity is connected to both a feed line and a discharge line for the cooling fluid.

Abstract: The object of the invention is to create a centrifugal compressor with a cooling appliance which is simpler but more effective. This is achieved by the feed device (27) for the gaseous cooling medium (31) opening into the separating gap upstream of the mainly radially extending gap region (20) of the separating gap (18).

Abstract: The object of the invention is to provide a method of operating a simply constructed centrifugal compressor equipped, in the region of the rear wall of the compressor impeller, with no sealing elements in the separating gap between the compressor impeller and the compressor casing, which method increases the service life of the centrifugal compressor. An appliance for carrying out the method is also to be made available. In accordance with the invention, this is achieved by introducing a cooling medium into the separating gap downstream of the leakage flow of the working medium and by finally removing this again after the cooling process has taken place. For this purpose, at least one supply duct for a gaseous cooling medium, the duct penetrating the compressor casing, opening into the separating gap in the region of the rear wall of the compressor impeller and directed onto the rear wall, and at least one removal duct for the cooling medium are arranged in the compressor casing.

Abstract: The object of the invention is to provide an improved method for sealing off the separating gap, formed between a rotor and a stator, in a non-contacting manner, with which method the service life of the components involved can be increased. In addition, an arrangement for carrying out the method is to be shown. According to the invention, this is achieved in that the flow layers (35, 36), having different circumferential velocities, of the working fluid (18) are divided after the choking action into a first partial flow (35') having a high circumferential velocity and a second partial flow (36') having a low circumferential velocity, the first partial flow (35') is merely deflected, only the second partial flow (36') is swirled and is finally directed parallel to the deflected first partial flow (35') into the latter. To this end, the opposing surface (24) of the choke point (22) is designed as a flow divider for the working fluid (18).