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 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).