Patent attributes
A centrifugal compressor is modified by forming a bypass between the leading edge of the compressor diffuser and a point downstream from the throat of the diffuser. The bypass may be unidirectional or bi-directional. In a bi-directional embodiment, an operable flow range of the compressor can be widened in both directions of a compressor map, i.e., extending both the surge and choke margins of a compressor at the expense of normal operating efficiencies. In a unidirectional bypass embodiment the flow range may be increased only in one direction, but there is no diminishment of efficiency of the compressor at normal operating conditions. The modification provides a simple expedient for increasing flow range without a need to redesign a compressor.