Do You Need a Desiccant Type Compressed Air Dryer?
It is widely believed that refrigerated compressed air dryers are excellent equipment for removing all the moisture from compressed air. However, condensate can still start if the temperature of the compressed air suddenly drops below the dew point it was dried at originally.
Refrigerated compressed air dryers are made to lessen the dew point of compressed air to normal range which is between 33 and 42 degrees. Of course, that depends on the application, as well as the operating condition. But how much cooler does the air have to be before condensation starts inside the air distribution system?
In many regions, temperature outdoors can drop to below 32 degrees Fahrenheit, and many manufacturing facilities have air piping exposed to this level of temperature.
When compressed air is exposed to a lower temperature than it has been condensed to, liquid will form. That is why it is important that you know the relative humidity of your compressed air. It is a simple relationship between the ambient temperature and the dew point of the air that is measured with a hydrometer. For instance, if the dew point is 42 degrees Fahrenheit and the ambient temperature is 42 degrees Fahrenheit, the relative humidity is 100% and you are going to see water! If the system is exposed to less than 32 degrees Fahrenheit, that water is going to turn to ice. The only way to address this is to reduce the dew point of the compressed air.
So, do you need a desiccant dryer?
If you get frozen pipes that completely stop the flow of compressed air. Frozen and damaged solenoid valves, and low system pressure that is caused by a stuck valve, then you should definitely consider a desiccant dryer.
Desiccant compressed air dryers can remove all water vapour all the way down to a negative 100 degree dew point. It absorbs the moisture using Activated Alumina and Molecular Sieve type desiccants. These dryers consume between 5 to 18% of compressed air supply. Dryers with purge controllers regenerate only when necessary, so they offer energy savings that could be worth the capital cost.
Desiccant dryers can also enhance the quality of compressed air which is very important for applications like painting, pharmaceutical applications; high accuracy machining that is sensitive to contaminants, powder coating, and more.
If you need more information about desiccant dryers, do not hesitate to call us! We’ll be happy to answer all your inquiries.