| 摘要 |
PURPOSE:To provide an automatic surge escaping apparatus for a turbo compressor, which is capable of escaping the turbo compressor from surging promptly and employing normal pressure control automatically in case that drastic drops of the discharge pressure detected by a pressure-drop detecting circuit is judged as surging by a surge judging circuit. CONSTITUTION:In case that drastic pressure drops DELTAP are caused two times within a predetermined limited time period DELTAT1 and it is judged as surging by a surge judging circuit 24, an automatic escape signal 26 is produced. Resultantly, current supply to an electromagnetic coil (not shown) is interrupted and a controlling work oil switching valve (not shown) is shifted for introducing work oil into a hydraulic cylinder (not shown) and forcing a blow-off valve (not shown) open, so that a turbo compressor is escaped from surging automatically. Since a normal pressure signal 27 is produced in place of the signal 26 after passing of a time DELTAT, current is supplied to an electric coil and said switching valve is shifted to its original position, so that a pressure controlling means is automatically brought into the state before occurrence of surging. |
