Compressed air dryer

Compressed air dryers are special types of filter systems that are specifically designed to remove the water that is inherent in compressed air. The compression of air raises its temperature and concentrates atmospheric contaminants, primarily water vapor, as resulting in air with elevated temperature and 100% relative humidity. As the compressed air cools down, water vapor condenses into the tank(s), pipes, hoses and tools connected downstream from the compressor which may be damaging. Therefore water vapor is removed from compressed air to prevent condensation from occurring and to prevent moisture from interfering in sensitive industrial processes.

Excessive liquid and condensing water in the air stream can be extremely damaging to equipment, tools and processes that rely on compressed air. For example, water can

  • cause corrosion in the tank(s) and piping made out of steel that may compromise its integrity
  • wash out lubricating oils from pneumatic tools
  • emulsify with the grease used in cylinders
  • clump blasting media and fog painted surfaces.

Therefore, it is desirable to remove condensing moisture from the air stream to prevent damage to equipment, air tools and processes.

Next to these damage mechanisms, in outdoor situations, water can accumulate and then freeze, leading to failure of components, e.g. braking systems.

There are various types of compressed air dryers. These dryers generally fall into two different categories: primary, which includes coalescing, refrigerated, and deliquescent; and secondary, which includes desiccant, absorption, and membrane. Their performance characteristics are typically defined by flow rate in standard cubic feet per minute (SCFM) and dew point expressed as a temperature.