Screw Air Compressors


Rotary-screw compressor

A rotary-screw compressor is a type of gas compressor, such as an air compressor, that uses a rotary-type positive-displacement mechanism. Screw-compressors perform well when higher pressure are needed than for example a regenerative blower.

We supply screw air compressors for various applications such as 15 Bar screw air compressors for laser cutting machines. When pressure requirements exceed 1000 millibars (1Bar), we turn to screw air compressors as the technological solution.

screw air compressor 15Bar
Screw air compressor for laser cutting industry.

Rotary screw compressors come in two main versions, oil flooded rotary screw compressors and oil-free screw compressors. Oil-free models deliver 100% oil-free air, but are more expensive. Oil free compressors are designed for 24/7 operation. They are more energy efficient and quieter than roots type blowers. Oil-injected or lubricated version needs oil to operate properly. This oil is later removed by the oil separator, but some oil remains in the air supply. They are positive displacement blowers.

Rotary-screw compressors tend to be smooth running with limited  vibration, thus not requiring a specialized foundation or mounting  system. Normally, rotary-screw compressors are mounted using standard  rubber isolation mounts designed to absorb high-frequency vibrations.

Two-stage screw compressors

Two-stage screw compressors are gearless and have two motors.

two stage screw compressor
Gearless two stage compressors have two motors.

 Oil free screw compressor

Screw compressor air delivery technology can deliver air at higher air pressures than regenerative and positive displacement blowers (see below, 1.25 Mpa is 12.5 Bar).

These are completely oil-free as there is no oil lubricant used in the air delivery system.

Pressure conversion table

Belt drive, oil lubricated air screw compressor

Variable speed drive and servo motor control

The screw compressors can be run of variable speed drives and servo motors. The servo motor transmission can regulate speed and torque very accurately. This translates into an air deliver system with low noise, high efficiency, energy saving, high  reliability, cost effective and low maintenance. Starting voltages are only up to 1.6 times the rated current.

Screw air compressors require air filters and air dryers.