Feedback control system for helical screw rotary compressors

摘要

An air motor, responsive to change in pressure of a compressed air supply line acts to control the flow of hydraulic motive fluid to a hydraulic motor which drives the capacity control slide valve of a helical screw, rotary compressor feeding the supply line. To eliminate hunting of the slide valve which shifts in response to change in compressor load, a mechanical feedback from the hydraulic motor modulates the flow of motive fluid to the hydraulic motor.