Tel: +0086-180-175-638-21
Home > News > What is a rotary air compressor?

What is a rotary air compressor?

DEHAHA DM-10A VSD Rotary Screw Air Compressor Industrial 7.5kW /DEHAHA Rotary Air Compressor OEM & ODM

A rotary compressor is a machine that compresses ambient air using a rotary motion. The air at the intake is gradually compressed using a screw configuration and positive displacement. The unit may be cooled using oil, air, or water. Rotary compressors may be single-stage or used in series to compress air in two stages.

Dehaha Variable Speed Screw Compressor 22kW 30HP PM Screw Air Compressor
Dehaha Variable Speed Screw Compressor 22kW 30HP PM Screw Air Compressor

How Does a Rotary Screw Compressor Work?

Rotary screw compressors operate via positive displacement – meaning they draw air into a chamber, reducing the volume.

The system draws air into one or more of its compression chambers and then closes them from the inlet. The volume of each chamber decreases, compressing the air internally until it reaches the designed built-in pressure ratio. The valve opens, discharging the air into the outlet system.

A rotary screw compressor’s defining characteristic is the presence of screws (usually there are two, but the compressor may have more or less). We also call these the male and female rotor elements, and the male rotor or a timing gear drives them. In oil-injected screw compressor technology, the male rotor drives the female rotor. In oil-free compressor technology, a timing gear drives both rotors for harmonic running, with minimum calculated clearance between both elements.

Rotary Screw Compressor 7.5kW-75kW PM VSD Type Compressor 8 bar 0.8Mpa Industrial Screw Air Compressors
Rotary Screw Compressor 7.5kW-75kW PM VSD Type Compressor 8 bar 0.8Mpa Industrial Screw Air Compressors

The twin elements rotate and spin in opposite directions. Air fills the space between the rotors, compressing it as they rotate. Then, the system releases the compressed air through the outlet. A screw compressor can run fast without valves or other forces causing imbalance, making it compact and efficient. To reduce losses, the system adjusts the speed of the screw rotors, especially since rotary screw compressors are more intricate than piston ones.

External gears synchronize the position of the counter-rotating screw elements. Since the rotors do not come into contact and create friction, the compression chamber does not need lubrication.As a result, the compressed air is oil-free. Precision engineering within the housing keeps pressure leakage (and drops) from the pressure side to the inlet at a minimum. Because the difference in air temperature between the inlet and discharge ports limits the internal pressure ratio, manufacturers frequently build oil-free screw compressors with several stages and inter-stage cooling to maximize the pressure reach.The gearbox driving the mechanism does contain lubricants; oil-free refers to the compression chamber itself, and the delivered air is free of foreign contaminants beyond those found inherently in the air that passes through the intake.

In liquid-injected rotary screw air compressors, the system injects a liquid (usually oil) into the compression chamber to assist with cooling, lubrication, sealing, and noise dissipation. The system specifically injects liquid to cool and lubricate the compressor’s moving parts, to cool the air being compressed in the chamber, and to minimize leaks during discharge. While oil is the most common liquid used today because of its lubricating and sealing properties, the system sometimes uses water and other polymers.The system then separates the oil and passes it through a filter and cooler before cycling it back into the process again. The compressed air can still be hot and often runs through a cooler, depending on end usage.


Stay updated with the latest from DEHAHA! Subscribe to our newsletter for exclusive insights, product launches, and industry news in the world of air compressors.

Electric Driven Portable Screw Air Compressor
Electric Driven Portable Screw Air Compressor
Electric Driven Portable Screw Air Compressor   Electric Driven Portable Screw Air Compressor
Scroll compression principle Compressor sucks air through air inlet located at outer scroll.Compression chamber goes smaller with rotary movement and trapped air is compressed.Compression chamber becomes minimum volume at the center of the scroll and air is pumped out through air outlet located at the center of scroll.These, suction, compression & discharging, process is repeated continuously. Long maintenance cycle with long life consumable parts. Compressor head replacement at every 10,000 hours or 4 years whichever comes earlier. Scroll oil free screw air compressor, 100% oil free for food industry, dental and medical industry. Technical parameter Model Capacity (m³/min ) Power (kW) Host architecture Exhaust pressure (Mpa) Noise (dB) Outlet diameter Dimensions (mm) L*W*H Weight (kg) DHH2OS 0.24 2.2 2.2*1 0.8 58±2 1/2 640*660*890 200 DHH3OS 0.41 3.7 3.7*1 0.8 58±2 1/2 640*660*890 220 DHH3OS 0.36 3.7 3.7*1 1 58±2 1/2 640*660*890 220 DHH5OS 0.60 5.5 5.5*1 0.8 58±2 1/2 640*660*890 240 DHH7OS 0.82 7.5 3.7*2 0.8 58±2 3/4 1000*690*990 300 DHH7OS 0.72 7.5 3.7*2 1 58±2 3/4 1000*690*990 300 DHH11OS 1.25 11 5.5*2 0.8 58±2 3/4 1000*690*990 340 DHH11OS 1.25 11 3.7*3 0.8 58±2 3/4 1150*690*1700 430 DHH11OS 1.08 11 3.7*3 1 58±2 3/4 1150*690*1700 430 DHH15OS 1.66 15 3.7*4 0.8 62±2 1 1490*1150*1290 620 DHH15OS 1.44 15 3.7*4 1 62±2 1 1490*1150*1290 620 DHH16OS 1.80 16.5 5.5*3 0.8 62±2 1 1150*690*1700 490 DHH18OS 2.14 18.5 3.7*5 0.8 65±2 1 1490*1150*1700 840 DHH18OS 1.77 18.5 3.7*5 1 65±2 1 1490*1150*1700 840 DHH22OS 2.55 22 5.5*4 0.8 65±2 1 1490*1150*1290 700 DHH22OS 2.55 22 3.7*6 0.8 65±2 1 1490*1150*1700 910 DHH22OS 2.11 22 3.7*6 1 68±2 1 1490*1150*1700 910 DHH30OS 3.40 30 3.7*8 0.8 68±2 5/4 1490*1150*2140 1140 DHH30OS 2.81 30 3.7*8 1 68±2 5/4 1490*1150*2140 1140 DHH33OS 3.60 33 5.5*6 0.8 68±2 5/4 1490*1150*1700 1010 Clean oil free compressed air Adopt 74 degree conicity dry seamless, more reliable seamless, eliminate air leakage. Not just compression process is oil free, but also on the afterward transportation adopt stainless steel pipe, stainless steel check valve, stainless steel air receiver(for air receiver mounted), ensure the quality of compressed air. High efficiency scroll air end Adopt the advanced oil free scroll airend, reliable bearing and grease, make sure the reliability and long life-span of airend, high precise machine for motivated scroll, fixed scroll and housing, ensure high efficiency of airend. Reliable seamless material, ensure compression chamber and lubricated transmit 100% be separate, ensure compressed air is oil free. High Reliability Cooling fan adopt integrated centrifugal impeller, low noise, high cooling air pressure, high cooling air, ensure the cooling air is enough, ventilation fan adopt silence axial fan, ensure the heat inside of cabinet could be eliminated in time. Heat exchange has been increased 20%-30%, anticorrosive treatment inner structure, after strict testing, ensure the exhausting air less than environment temp.+10-15ºC, reduce the burden of downstream equipment. Adopt direct driven, not belt driven, improve transmission efficiency & reliability, reduce the maintenance cost of changing belt. Project case 30Kw 120CFM compressor 8bar pressure oil free rotary scroll air compressor
DEHAHA Oil Free Rotary Scroll Air Compressor
DEHAHA Oil Free Rotary Scroll Air Compressor       Technical parameter Model Capacity (m³/min...
Centrifugal Compressor for Oil refining
Centrifugal Compressor for Oil Refining
Centrifugal Compressor for Oil Refining   Technical Parameter   Applications


1199 Xiyuan Road, Qidong City, Jiangsu Province

Copyright © 2024 DHH
Powered by DHH Compressor

Scroll to Top

Contact Us