| 摘要 |
PROBLEM TO BE SOLVED: To provide an energy saving tandem type compressor capable of preventing phenomenon that a motor does not rotate due to overload.SOLUTION: When the second motor is energized, firstly, a bypass circuit for returning compressed air to an intake side of a first compressor 120 acting as a tandem mating compressor is arranged before a discharging port of a second compressor 220 to avoid overload caused by exceeding a critical backpressure, secondly, closing a suction valve not to cause a pressure in the compressor to be increased and a torque required for compression of air is reduced, thirdly, in order to reduce an agitating resistance of lubricant agent applied to a screw in the compressor, there is provided a valve for adjusting a feeding amount of lubricant agent to decrease a load applied to a motor at the time of its energization as much as possible and when the rotation reaches a stable region, an operation opposite to the aforesaid first to third operations is carried out, i.e. the bypass valve is closed, the intake valve is opened, a lubricant agent feeding amount adjustment valve is returned back to its usual set and the lubricant agent is divided to flow by a rated flow rate and two compressors can be energized in sequence even in the case of presence of one receiver tank 340.SELECTED DRAWING: Figure 6 |
