Centrifugal Compressor

Abstract

A centrifugal compressor of the present invention can be operated without degrading the efficiency of the impeller or reducing the operating range thereof even when the centrifugal compressor is operated in an environment in which a liquid likely mixes. A centrifugal compressor of the present invention includes a rotating shaft which rotates rotationally, and an impeller including a hub fixed to the rotating shaft and plural vanes fixed to the hub at a predetermined interval in a circumferential direction. The centrifugal compressor compresses a fluid by rotation of the impeller. The hub includes plural through holes penetrating the hub from a front side to a rear side of the impeller.

1 . A centrifugal compressor comprising:
 a rotating shaft which rotates rotationally; and   an impeller including a hub fixed to the rotating shaft and a plurality of vanes fixed to the hub at a predetermined interval in a circumferential direction;   wherein the centrifugal compressor compresses a fluid by rotation of the impeller, and   wherein the hub includes a plurality of through holes penetrating the hub from a front side to a rear side of the impeller.   
     
     
         2 . The centrifugal compressor according to  claim 1 ,
 wherein the through holes are provided between the vanes on the rotating shaft side.   
     
     
         3 . The centrifugal compressor according to  claim 1 ,
 wherein the through holes are located between an inlet radius Rh of the hub and an inlet radius Rsh of a shroud of the vanes.   
     
     
         4 . The centrifugal compressor according to  claim 1 ,
 wherein a plurality of grooves extended to the through holes are formed along an inner surface of the hub.   
     
     
         5 . The centrifugal compressor according to  claim 4 ,
 wherein the grooves and the through holes are located between an inlet radius Rh of the hub and an inlet radius Rsh of a shroud of the vanes.   
     
     
         6 . The centrifugal compressor according to  claim 1 ,
 wherein the impeller includes a leakage reducing member on the rear side, the leakage reducing member reducing a leakage flow flowing back from an outlet of the impeller to the through holes.   
     
     
         7 . The centrifugal compressor according to  claim 6 ,
 wherein the leakage reducing member includes a protruded portion protruded in a axial direction from a rear side of the hub and an unevenness portion formed in a part of a casing to face the protruded portion, and   wherein the protruded portion and the unevenness portion form a sealing portion.