Operation of a Rotary Screw Compressor
The rotary screw compressor is a positive displacement compressor, made of two intermeshing helical rotors contained in the housing. The driving rotor is usually made of four lobes and the driven rotor usually consists of six lobes. As the helical rotor grooves pass over the suction port they are filled with gas. As the rotors turn, the grooves are closed by the housing walls, forming a compression chamber. to provide lubrication, sealing, cooling and avoid any metal to metal contact, lubricant is injected into the compression chamber. As the rotors mesh, the compression chamber volume decreases, compressing the gas/lubricant mixture toward the discharge port where it exits as the chamber passes over the port. Most manufacturers build a slide stop valve into the casing that can be actuated either manually or with an air or hydraulic piston. This variable volume ratio allows the packager to customize the built in compression ratio as closely as possible to the actual field conditions. Later, the operator can adjust his compression system to meet changing conditions.
The rotary screw compressor is a positive displacement compressor, made of two intermeshing helical rotors contained in the housing. The driving rotor is usually made of four lobes and the driven rotor usually consists of six lobes. As the helical rotor grooves pass over the suction port they are filled with gas. As the rotors turn, the grooves are closed by the housing walls, forming a compression chamber. to provide lubrication, sealing, cooling and avoid any metal to metal contact, lubricant is injected into the compression chamber. As the rotors mesh, the compression chamber volume decreases, compressing the gas/lubricant mixture toward the discharge port where it exits as the chamber passes over the port. Most manufacturers build a slide stop valve into the casing that can be actuated either manually or with an air or hydraulic piston. This variable volume ratio allows the packager to customize the built in compression ratio as closely as possible to the actual field conditions. Later, the operator can adjust his compression system to meet changing conditions.
Typical Applications
Rotary screw compressors are ideal in large volume/low suction pressure applications and to upgrade existing reciprocating compressor installations. Since they operate with few moving parts, low maintenance and high reliability are inherent in rotary screws.
Features
 | Fewer moving parts means the elimination of maintenance items such as compressor valves, packing and piston rings and the associated downtime for replacement as utilized with a reciprocating compressor. |
| The absence of metal-to-metal contact allows the compressor to run at high speeds, which results in more compact units and a reduction in package costs. |
| Continuous flow of cooling lubricant permits much higher single-stage compression ratios. |
| Rotary screw technology eliminates pulsations, common in other compressor types, virtually eliminating any excessive vibration possibilities. Some rotary screw compressor feature an internal speed increasing gear with numerous gear ratios available for matching compressor performance to pressure conditions. |
| Single stage operation from low pressure or vacuum to 150 psi or above is possible with the oil flooded rotary screw. |
| Most rotary compressors offered by VR Systems feature all iron or steel construction with no cooper alloys, making these compressors compatible with corrosive gas streams. VR Systems utilizes the following manufacturers' rotary screw compressors: |
![[Valid Atom 1.0]](valid-atom.png "Validate my Atom 1.0 feed")
