DEVICE FOR PREVENTING SURGING OF COMPRESSOR

PURPOSE:To provide a device for preventing surging of a compressor, which can immediately detect surging caused by any unexpected factor and then isolate the operating state of the compressor from a surging region, and can also enhance compression efficiency more than before by effective use of the capacity of the compressor. CONSTITUTION:Piezoelectric surge sensors 18, 19 are disposed respectively on the inlet and outlet sides of a compressor 1 and a normally closed spill-back valve 8 is disposed within a branch line 5 connected to a line 3 on outlet side of the compressor 1, and a controller 20 is provided in the required position which, when voltage signals 21, 22 input from the surge sensors 18, 19 abruptly rise and pulsate, outputs a command signal 23 to open the spill-back valve 8 until pulsation of the voltage signals 21, 22 is stopped after detection of surging in the compressor 1.