MAN Diesel & Turbo manufactures tailor-made process gas screw compressors. This animation shows and explains its working principle in 3D.As you will see, the design of a screw compressor combines the advantages of a positive displacement machine with those of a rotating machine.
source/image: MAN Energy Solutions
The basic principle of a screw compressor is as the male and female rotors are rotating in opposite direction they draw air in between them. Referred to generally as a twin screw compressor each rotor comprises of a set of helical lobes affixed to a shaft.
Screw Compressors are commonly used to replace piston compressors where large volumes of high-pressure air are needed, either for large industrial applications or to operate high-power air tools such as jackhammers and impact wrenches.
For smaller rotor sizes the inherent leakage in the rotors becomes much more significant, becoming less practical than piston types for smaller volume air compressors.The gas compression process of a rotary screw is a continuous sweeping motion, so there is very little pulsation or surging of flow, as occurs with piston compressors./ wikipedia