| 摘要 |
PCT No. PCT/SE95/01418 Sec. 371 Date May 28, 1997 Sec. 102(e) Date May 28, 1997 PCT Filed Nov. 28, 1995 PCT Pub. No. WO96/17175 PCT Pub. Date Jun. 6, 1996A rotary screw compressor having one or more stages (10, 20) is provided with a lift valve (14, 24) on each stage for unloading the compressor at starting up and rest periods. Each lift valve (14, 24) is biased by a spring (15, 25) towards an open position and can be closed by an actuator (17, 27). Each valve actuator (17, 27) is automatically controlled by an air conduit (32) establishing air communication between the discharge channel (23) of the compressor and each valve actuator (17, 27). |
