April 9, 2019
Compressed air will always contain some level of moisture depending on the environment and ambient temperature surrounding the compressor. Using the air while it contains moisture can cause a number of issues for your tools, other equipment and ultimately your business.
Water contamination can lead to microbial contamination, corrosion, blocked or frozen valves, cylinders, air motors and tools and premature wear/failure of equipment. Water contamination of compressed air systems can reduce production efficiency and increase manufacturing costs. If you are in an automotive shop using compressed air for your tools, the tools will rust over time if they are constantly powered by humid air. Spray painting can also be affected if water enters the paint stream. If you are using compressed air to power the actuators in your brewery, these too will rust, become clogged and shut down because of the moisture coming in contact with the equipment. Textiles using compressed air to manufacture fabric run the risk of ruining products by letting moisture come in contact with fabrics, dyes and other items.
So How do I Remove the Risk of Ruining my Equipment and Finished Products?
To prevent any of the risks above, air dryers are used to remove the moisture following the compressed air process. Dry compressed air is a concept with a wide range of meanings and dew point is an indication of how dry the compressed air is or needs to be. While air can be compressed, water cannot be compressed, and the cost of a new air dryer is cheaper than the loss of products and production.
For automotive shops, breweries and other small industrial applications, refrigerated dryers are often used to remove moisture from the compressed air before it reaches any equipment downstream of the compressor. 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. The moisture laden air then undergoes a mechanical separation process where the 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. For larger applications and industries that need very dry air, desiccant dryers are used. Desiccant dryers use desiccant material 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.