How Does a Rotary Screw Air Compressor Work?

There are many different kinds of air compressors. Depending on your needs, a rotary screw air compressor could be the right fit for you. Here are the details on how a rotary compressor works.

Rotary Air Compressor or Reciprocating Air Compressor

Air compressors come in a variety of designs for different uses. The two most common types of air compressors are rotary and reciprocating. Both of these types of air compressors use positive displacement to pressurize the air.

According to the Compressed Air & Gas Institute, positive displacement is the act of trapping air in an enclosed space and making the space smaller by a mechanical process. A reciprocating compressor has a piston that slides back and forth to compress the air. Let’s look a bit closer at how a rotary compressor works.

How Does a Rotary Screw Air Compressor Work?

There are several types of rotary air compressors. Rotary screw air compressors are unique because they have two cone-shaped screws that fit together. These screws are set into a cylindrical casing. It is within this casing that the air is pressurized.

Air compressors draw air from the environment into the casing at the inlet valve. This air is pulled into the space between the screws. As the cone-shaped screws turn, they trap the air in the cavity between the screw and casing. The screws reduce the amount of space available for the air, which creates pressure. The air compressor then discharges the pressurized air on the opposite end of the casing.

Imagine the flow of air entering the wide end of a funnel. Air is pushed into the funnel and forced out the other end. The air that comes out of the narrow end of the funnel is more pressurized than when it enters. This is a very basic version of how this type of air compressor works. Once the air comes out of the narrow end, it enters a reservoir.

What Are the Benefits of Rotary Screw Air Compressors?

People choose rotary screw air compressors for a reason. It is because they provide a slew of benefits over other types of air compressors that make them perfect for a variety of applications and industries.

Works in All Conditions

Depending on the industry, air compressors need to handle different environments. Rotary screw air compressors work perfectly inside and outside in hot or cold temperatures. So, whether a construction team needs it for demolition in the summer or a manufacturer needs a compressor in a cold factory, a rotary air compressor will meet their needs.


One great property of this type of compressor is they use resources more efficiently. They use less oil and produce less heat, making them an excellent choice for industries with limited funding and space.

Meets Safety Requirements

Does your industry have stringent safety requirements? For example, in agriculture and food production, consistent temperature is key. A rotary air compressor meets those standards because they can operate under all sorts of conditions and provide consistent power.

Easy to Maintain

Rotary air compressors actually have fewer parts than other types, making them way easier to maintain. The fewer parts you have to worry about, the less money you’ll have to pay and the less time you’ll have to spend ensuring the compressor is in good condition.

What Are the Types of Rotary Screw Air Compressors?

Oiled or Non-Oiled Systems

Some air compressors use oil to lubricate the system and reduce the amount of heat created by compression. Rotary air compressors may be oil-lubricated, water-lubricated, or oil-free. The right system depends on your usage. For example, hospitals and labs may need an oil-free system to make sure they are following health and safety standards.


A rotary air compressor can be either base-mounted or tank-mounted. A base-mounted unit stands alone and works well in limited spaces. A tank-mounted unit has a tank reservoir for compressed air.

Total Air Systems

Total air systems essentially combine base-mounted and tank-mounted to create a unit that both saves space and purifies air.

Variable Speed

Do you need to control the speed of your compressor? A variable speed unit has motor control drives, enabling users to control the speed of the system. This can also improve energy efficiency.

How to Choose a Rotary Compressor

There is a wide range of applications for compressed air. Depending on your project, air power may have advantages over electric or hydraulic power. Rotary air compressors are great for projects where you need a steady stream of air without pulses. Rotary compressors are also great for small spaces because they produce a large volume of air without taking up much room.

Make sure that the air compressor you choose is efficient, made of high-quality materials, and has a minimal impact on the environment. It needs to be compatible with your existing equipment and affordable when compared to similar systems. Working with an air compressor company that prioritizes helping other businesses can help you feel confident in your choices.


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