What is a Rotary Screw Compressor?

A longtime staple in many manufacturing processes, the rotary screw compressor is a true workhorse that makes many amazing feats of modern technology possible. The rotary screw compressor utilizes a positive displacement mechanism of intermeshing rotors, referred to as a rotary screw, air-end. These compressors are used commonly as replacements for automotive, industrial and commercial applications that require high pressure air in large volumes. Although less frequently, these compressors are also referred to as twins screw compressors. At BOGE, we develop innovative compressor technology that is used extensively in various applications around the world.

Rotary Screw Air Compressor Process

The process of compression in a rotary screw compressor is different than the process in a reciprocating piston compressor. The rotary screw air end produces compression in a continual sweeping motion. Unlike with the piston compressor, there is very little surge of flow or pulsation with these compressors. Rotary screw compressors also utilize rotors, which consist of two intermeshing helical shaped screws, to compress the air. The rotors in these compressors are precision machined to exceptionally tight tolerances to where the rotors nearly touch when meshing together and are within typically only a few thousandths of an inch in separation.

Oil Lubricated Rotary Screw Compressor Design

In oil lubricated rotary screw compressors, lubricating oil spans the space between the rotors, forming a hydraulic seal and moving mechanical energy between the driven and driving rotor. Air comes into the system at the suction side of the air-end and travels through the rotor vanes while the screw rotors rotate. The oil and air are forced through the air end by the action of the intermeshing rotors and eventually withdrawal at the end of the screws. The oil and air then pass through a separation process. The oil is cooled, filtered, and returned back into the air-end within this closed loop system. The air is cooled and transferred to air lines and a receiver.

Rotary Screw Air Compressor Applications

Rotary screw air compressors are present in industrial facilities and construction sites around the world providing on-demand supply of compressed air for everything from food packaging to pneumatic pumps and jackhammers. Rotary compressors can be oil-free or oil lubricated depending on the sanitary requirements of the application.

Two-Stage Oil-Free Air End

     Oil Lubricated Air End

Contact us today at BOGE for more information about the rotary screw compressors we offer.