What Is a Screw Compressor?
A screw compressor is a type of positive displacement compressor that compresses gas through the rotation of a screw rotor. This rotor forms a compression chamber with the casing. As it rotates, it continuously compresses the gas, resulting in lower vibration and noise compared to reciprocating compressors. This efficiency makes screw compressors popular in medium to large capacity applications.
Uses of Screw Compressor
Screw compressors are employed in a wide range of applications, including:
- Air Compressors: Used in factories for powering various tools and equipment like drills, hammers, grinders, and for processes like molding, conveying, and surface treatments.
- Gas Compressors: Common in refrigerant compressors for air conditioning and refrigeration, especially in medium to large facilities.
Principles of Screw Compressor
The working principle of a screw compressor involves altering the volume of a chamber formed between the screw rotor and casing. This process includes stages of gas intake, compression, and discharge. Unlike reciprocating compressors, screw compressors lack intake and discharge valves and rely on the axial movement of the chamber for gas processing.
Types of Screw Compressors
Screw compressors are available in lubricated and oil-free models:
- Lubricated Compressors: These use oil for lubrication and cooling, suitable for industrial applications but may leave oil residue in the compressed gas.
- Oil-Free Compressors: Utilize oil-free bearings and are ideal for industries requiring oil-free air, like food processing and semiconductor manufacturing.
They are also categorized by the number of screws, including single, twin, and triple-screw compressors.
Other Information on Screw Compressor
For lubricated compressors, oil plays a vital role in sealing gaps, preventing gas leakage, and reducing heat. Selecting the right oil and regular maintenance are critical to prevent issues like oil degradation and machine malfunction.