One thing that’s found in nearly every industrial environment is an air compressor. Compressed air is used to power tools, operate packaging and automation systems, run conveyors, control valves, and more. Pneumatic tools remain popular because they’re smaller and lighter than their electric counterparts, offer infinitely variable speed and torque, and can often be safer than electrical devices in harsh or wet environments.
To power these systems, compressed air must first be generated, and that starts with the air compressor. There are two main categories of air compressors: positive displacement and dynamic. Positive displacement compressors trap a given quantity of air in a chamber, then mechanically reduce the volume to increase the pressure. Dynamic compressors raise air pressure by accelerating continuously flowing air with a high-speed impeller. The velocity energy of the air is then converted into pressure energy.
One of the most common dynamic types used in industrial applications is the centrifugal air compressor. In a centrifugal compressor, air enters the center of a high-speed rotating impeller, which can spin at more than 50,000 RPM. The impeller’s blades fling the air outward by centrifugal force, increasing its velocity and pressure. The kinetic energy of the moving air is then converted into additional pressure as it slows down in a diffuser. Centrifugal compressors are generally used where large volumes of air are required. They can handle flows from a few hundred CFM up to 100,000 CFM or more, with most plant installations falling in the 1,000–5,000 CFM range.
According to the Compressed Air Challenge, some of the key benefits of centrifugal air compressors include their ability to deliver oil-free, contaminant-free air, and the fact that they are often supplied as complete packaged systems up to 1,000 HP. They scale well, as the cost per CFM improves as size increases, do not require special foundation requirements, and are ideal for high-volume air delivery.
Of course, there are trade-offs to consider. Centrifugal compressors have limited capacity control options, reduced efficiency at partial load, and their high rotational speeds require precision bearings and specialized maintenance. They also tend to have a higher initial purchase cost compared to smaller positive-displacement units. Despite these considerations, centrifugal air compressors remain a reliable choice for facilities that require large, continuous volumes of clean, oil-free air.
Once your facility’s air is generated, the next step is making sure it’s used efficiently. Compressed air is one of the most expensive utilities in a plant, and any wasted air means wasted energy. That’s where EXAIR’s line of engineered Air Nozzles, Safety Air Guns, Super Air Knives, and Optimization products come into play, helping you get the most from every SCFM your compressor produces. If you’re looking to improve your system’s efficiency or solve a specific application issue, contact one of our Application Engineers. We’ll help you get the most out of your compressed air system from the compressor room to the point of use.
Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
X: @EXAIR_TD
Image courtesy of the Compressed Air Challenge
