The Different Types of Industrial Air Compressors

Compressed air is an essential energy source for the industrial sector. It is often used to power pneumatic tools and automate key equipment.

According to the U.S. Department of Energy, approximately 10% of the electricity consumed by an industrial facility is used to generate compressed air. For some plants, compressed air generation may account for at least 30% of the total electricity used.

Maintaining a reliable supply of compressed air is critical for many industrial facilities. But compressed air also plays a crucial role in non-manufacturing sectors, including mining, construction, oil and gas, agriculture, transportation, and recreation.

Air compressors work by putting atmospheric air under pressure to produce tighter air. This air can be stored in a tank for use as an energy source in the future.

Factors to Consider When Choosing an Industrial Air Compressor

Industrial air compressors come in different sizes, designs, and motor types. They may also vary in terms of features, power, and amount of airflow and pressure they produce.

Businesses need to know how to select an air compressor that meets their needs and produces the results they want while keeping energy costs manageable. Investing in the wrong compressed air system can ruin your operations. For instance, a compressor that doesn’t have enough power might result in system failure and safety hazards. Likewise, a compressor with more power than necessary might increase energy expenditure.

Here are a few factors to consider when selecting the right air compressor for your business needs:

Material – Air compressors are constructed from various materials. Those made from steel and cast-iron often last longer than other types. Choose a material that can resist wear, corrosion and everyday wear and tear. The longer your compressor lasts, the lower your maintenance costs will be.

Drive system type – You may choose between a diesel-powered or electric motor. Electric motors require less maintenance but need a continuous source of electricity. This may not be the best choice if you’re working on various job sites.

Some air compressor models are equipped with variable frequency drives or VFDs. This type of drive adjusts the amount of energy to be discharged depending on the airflow demand of the application. VFDs alter the voltage and motor input frequency, reducing energy consumption and operating costs.

Tank size – Storage tanks, also known as air receivers, are used to store compressed air before it enters the equipment or the piping system. A larger tank can store more pressurized air that will be available for immediate use. A smaller tank will require the compressor to work harder to achieve the same output.

Duty cycle – The duty cycle indicates the amount of time a compressor can function versus how long it needs to rest before it can start running again. If you need full power at all times, you’ll want a compressor with a 100% duty cycle.

Cooling system – Cooling systems use air, water, or oil to cool the compressor’s internal parts and prevent overheating. They may be enclosed or open, and use either axial or centrifugal cooling fans. Some air compressors may also feature an after cooler or air dryer to eradicate moisture and keep compressed air safe and sanitary.

Types of Industrial Air Compressors

Positive Displacement Air Compressors

A positive displacement compressor draws in atmospheric air into one or more of its chambers. The chamber’s volume decreases to compress the air until the pressure achieves the designed build-in pressure ratio. The valve then opens to release the air into the outlet system.

Regardless of outlet pressure, positive displacement compressors operate with a constant flow. The two most common types of positive displacement air compressors ar rotary screw compressors and reciprocating air compressors.

Rotary screw compressors

As the name suggests, this type of compressor uses rotary movements to compress the air.  It features a set of male and female rotors that traps air in between when the rotors are turned simultaneously.

Rotary screw compressors draw air and oil into a void that’s created as the two rotors mesh together.  Once the rotors move through the air-end, the cavity decreases in size throughout the rotation, compressing the air. Rotary screw compressors are currently the industry standard in plant air compressors, from about 25 to 300 horsepower.

Reciprocating air compressors

Reciprocating compressors use a piston in constant motion to suck air into a chamber for compression. The air is then released through a discharge valve and stored in a tank.

Reciprocating piston compressors can offer up to 1000 horsepower and come in single- or double-chamber designs. This means air may be compressed on only one or both sides of the piston. These types of compressors are air- or water-cooled.

Two-Stage Air Compressors

In dual-stage compressors, the air is pressurized twice. Instead of sending compressed air directly to a storage tank, the air is transferred to a piston for a second stroke. The resulting double-pressurized air is then cooled and stored in a receiver tank for future use.

This type of compressor uses double the mechanisms to capture air as well as two cylinders to store the compressed output.

Centrifugal Air Compressors

A centrifugal air compressor is a type of turbo or dynamic compressor that runs at a constant pressure. It features a radial design, and its performance is influenced by external factors, including changing inlet temperatures.

To transmit kinetic energy into the air stream, a centrifugal compressor boosts the velocity of the air using a rotating element. The kinetic energy is then transformed into potential energy in the form of pressure.

Find the right type of air compressor for your application

An industrial air compressor is a valuable investment. The right type of air compressor can boost productivity, your capacity to innovate, and ultimately, your bottom line.  

JHFoster can help you select the air compressor that’s right for the job and will last many years. We’ll help you determine your airflow requirements and the amount of pressure needed for the specific application.

Contact one of our experts to get a quote.