March 12, 2019
Compressed air is a helpful asset for thousands of different industries, but it can contain moisture and other contaminates that can ruin a final product or damage equipment that is downstream of the compressor. In almost all applications, it is recommended to use either a refrigerated or a desiccant air dryer to benefit both your final product and any equipment that is powered by compressed air.
But what is the difference between a refrigerated and a desiccant dryer?
Refrigerated air dryers use the same cooling principal as typical air conditioning units in homes across the world. Using the refrigeration system and passing compressed air through a heat exchanger, the air is cooled to approximately 40 °F. As the air cools, water droplets begin to form in the air due to condensation much like the water droplets that form on the outside of a cold drink. The moisture laden air then undergoes a mechanical separation process where the liquid or “condensate” is separated from the air stream. The air is then rewarmed using the incoming air which lowers the relative humidity of the air and traps any remaining moisture in a vapor form. Refrigerated dryers are often used in manufacturing plants, automotive shops, food packaging plants and breweries. They come in both cycling and non-cycling variants to fit different applications while also being energy efficient. Refrigerated dryers are the most popular dryer type.
Desiccant or adsorption dryers use desiccant material (similar to the non-edible packs you find in your newest box of shoes) to adsorb and remove the humidity from compressed air. With this method, a pressure dew point as low as -100 °F can be reached. A desiccant dryer should be used when the ambient temperature goes below freezing point, to avoid ice forming in pipes and applications. Desiccant dryers are also used in applications such asmold prevention, medical applications, textiles and food factories to keep the air as dry as possible to avoid moisture contamination. Desiccant dryers also help prevent corrosion of pipes, decreased efficiency of tools and freezing of water in your pipes.