Why Do You Need An Air Dryer?
11 November 2022
Since the atmospheric air contains different amounts of moisture depending on the temperature - higher air temperatures can absorb more water, while air cannot absorb as much water at lower temperatures. This also applies to compressed air systems, and if our body is an indication of how excess water and moisture can affect performance, imagine how this affects a compressed air system.
Untreated compressed air that contains solid liquid and gaseous contaminants poses a significant risk as it can damage your air system and your end product. Moisture, one of the main components of untreated air, can cause the following problems:
- Causing rust and wear of the inner part of the compressed air line, which leads to holes and thus to air leaks, which leads to a drop in pressure and thus to energy and money loss!
- May adversely affect the colour, adhesion and surface finish of the paint applied with compressed air.
- Can endanger the process industry, where many operations depend on the proper functioning of the pneumatic controls. Malfunction of these controls due to rust, scale, and clogged openings can damage the product or result in costly shutdowns.
- Can freeze in control lines in cold weather, which can cause the controls to malfunction.
- Causes corrosion on air or gas powered instruments, gives incorrect measured values, interrupts or switches off plant processes.
- Finally, contact of air with your end product can lead to rejection of your product and affect your profitability.
To avoid malfunctions and interruptions due to water and moisture in the pipes, the compressed air must therefore be dried wirh aftercoolers and drying devices
Choosing the Right Compressed Air Dryer
Before you look at the different types of dryers available, consider what to know when deciding which dryer is best for your specific needs:
- Know the specific uses of compressed air, the required air quality and the maximum permissable water content according to ISO 8573-1:2010 edition.
- You know the maximum ambient temperature at which the air dryer is operated. However, Atlas Copco has all types of air drying technologies to achieve any required air quality at any working environment temperature.
- You need to know the minimum working inlet pressure to the air dryer if the pressure decreases with increasing volume and the performance if the air dryer is impaired.
- Know the lowest temperature that the compressed air line passes through.
- If you have multiple compressors, it is always better to use a separate dryer for each compressor (number of dryers according to number of compressors).
As a rule of thumb, a refrigerant dryer is suitable for most industrial applications because it lowers the pressure dew point (commonly referred to as PDP, i.e. the point at which condensation forms) of your compressed air to +3°C. That means you don't have to worry about condensation unless your piping is exposed to freezing temperatures.
However, some applications require air with a much lower dew point. In this case, you need to take a look at the dry air drying technology, with which you can reach a dew point of up to -70°C. We recommend that you refer to the ISO 8573-1:2010 standard when specifying new air compressor systems and when reviewing your air system, but if you need ideas, our air experts will be happy to answer your questions at any time.
Discover the full range of Atlas Copco compressed air dryers and their applications.