Simultaneous speed and slide valve control in a twin screw compressor - slide valve vibration behaviour

A screw compressor may be run at a higher average level of efficiency if simultaneous speed and slide valve control are employed. Such an arrangement calls for a careful consideration of the vibratory response of the slide valve actuator spindle, a slender component having relatively low frequencies, which would be subjected to a far greater range of excitation frequencies than in the constant speed machine. This paper considers this problem and comments on the actions required from designers.