top of page
  • Peg Minichiello

How Do Oil Free Air Compressors and Heatless Desiccant Dryers Work?

Updated: Sep 3, 2019

Compressed air needs to be dry to be viable. That’s why picking the right dryer is as important as selecting the best air compressor. But which dryer and compressor system is right for you?

Currently, oil free air compressors and heatless desiccant dryers are some of the most popular options. For this reason, we’ve gathered some info about how these systems work so you can decide if you want them for your plant.

The Process Behind Oil Free Air Compressors

The basics of the oil free air compression process are very simple. At first, air is sucked in at the intake until the volume of the compressor is full. Once it’s filled, a lobe pushes down and compresses the cylinder with three times the intake air’s normal pressure. After the air is compressed, it’s released.

The rotors of oil free air compressors don’t touch, unlike lubricated compressors. Although this allows a surplus of compressed air to be created, it does create a few issues, such as:

Temperature rises drastically meaning that air needs to be intercooled and aftercooled before being delivered to the dryer.The constant unloading and reloading of compressed air means that the capacity control valve needs to be maintained regularly.High temperatures cause condensation which can leak water into the device and destroy the compressor.

Despite these issues, oil free air compressors are more efficient than their lubricated counterparts. With the right maintenance, they can even reduce energy costs and help your plant run more smoothly.

How a Heatless Desiccant Dryer Works

A heatless desiccant dryer, or regenerative dryer, works like a magnet. It uses a process called “adsorption” to attract water molecules in compressed air to a solid called a desiccant. The air is filtered through desiccant beads at a normal pressure and temperature. When the air is rejected, it’s dry and can now be used.

Once the process is complete, the desiccant can be reused by lowering the pressure, which causes it to reject the water molecules. While one desiccant tower is being regenerated it requires about 15% of the processed air, which is known as “purged” air. Although this can be costly, it helps maintain the system for many years.

Heatless dryers have a variety of controls, such as:

  • Timers

  • Depressurization

  • Repressurization

  • Dewpoint demand

Are These Systems Right for You?

Knowing whether a heatless desiccant dryer and oil free compressor system is right for you can be challenging. That’s why you should contact CDA. Our team members are experts when it comes to compressors & air dryers (+ 34 to -100 F dew point). CDA Systems has been a long time representative of SPX Flow Pneumatic Products (PPC) dyers.  With a consultation, we can determine what your plant needs. All you need to do is reach us on: 925.667.3400/

13 views0 comments

Recent Posts

See All
bottom of page