METHOD AND DEVICE FOR INCREASING OPERATING AREA OF CENTRIFUGAL COMPRESSOR

摘要

PROBLEM TO BE SOLVED: To increase the operating area of a centrifugal compressor without lowering an oiler head. SOLUTION: An annular treatment hollow part 8 is provided in the shroud wall 5 of a centrifugal compressor housing 6, and a first opening part 9 allowing the installation position of an impeller 1 to communicate with the treatment hollow part 8 and a second opening part 10 allowing the treatment hollow part 8 to communicate with the position on the upstream side of the first opening part 9 are provided in the shroud wall 5 so as to circulate air (a) during low flow rate operation. Louvers 11 disposed aslant in the direction reverse to the rotating direction of the impeller 1 are provided in the second opening part 10 at equal intervals so as to provide a flow in a reverse turning direction to the air (a) sucked into the treatment hollow part 8 when the air is flown out through the second opening part 10.