| 摘要 |
The shroud or stationary housing for the impeller of a centrifugal compressor includes inherent means for selectively controlling the displacement thereof during operation of the centrifugal compressor, and in a manner to substantially maintain uniform spacing or clearance between the shroud and the blade tips of the rotating impeller in order to achieve improved performance at both part and full power operating conditions. The shroud is preferably formed of a unitary member including an annular, concave disc portion substantially corresponding to the configuration of the tips of the blades of the impeller, with the annular concave disc portion being rigid and connected to a fixed flange support portion by a flexible, annular diaphragm which extends generally perpendicular to the shaft of the impeller. The annular diaphragm is sufficiently flexible such that during operation of the centrifugal compressor, the differential thermal and pressure forces generated along the length of the blades within the compressor cause deformation of the flexible diaphragm and a substantially linear movement of the rigid, concave disc portion relative to the flange support portion. The movement of the annular concave disc portion substantially corresponds to the change in configuration of the blades, thereby minimizing blade tip losses.
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