What is an Air Dryer?
A compressed air dryer is a device for removing water vapor from compressed air. They are commonly found in a wide range of industrial and commercial air compressors. Water vapor is removed from compressed air to prevent condensation from occurring and moisture from interfering in sensitive industrial processes.
How do Air Dryers work?
There are various types of Air Dryers. The two most common air dryers are Refrigerated Dryers and Desiccant Dryers.
Refrigerated air dryers are used in most industrial applications and remove moisture and contaminants from compressed air by cooling the compressed air as low as 38°F, reducing the pressure dew point of the compressed air. The dew point refers to the temperature at which condensate forms. That is when the air reaches 100% humidity and can’t hold any more water. After condensate has formed, it is removed and then the air is reheated and dried.
Desiccant air dryers utilize the adsorption method of moisture removal and are applied when air quality requirements call for pressure dew points below 38°F and can produce few points as low as -100 °F. Water in the compressed air is chemically bound to an adsorption material and dissolves. Both the water and material is then discarded.
Most desiccant dryers use a dual tower design where one tower is drying while the other is being regenerated. Whether using a heatless, heated or heated blower dryer, the compressed air produced is thoroughly dried as it is directed through the on-line desiccant-filled tower of the dryer. As the desiccant in this tower adsorbs moister from the air, the desiccant in the dryer’s offline tower is purged of moisture and readied for use. The basic difference in the three technologies is the manner in which moisture is desorbed from the desiccant, also known as regeneration.
What happens if I don’t have an Air Dryer?
As water is always present in the air, when the air is compressed, the water also comes with it but cannot be compressed. Temperature and humidity determine how much water there is and remains in the air. When some processes demands large amount of air, the built up water gets carried through the machine in either the liquid or vapor phase and remains inside unless it is somehow removed. Normally, the compressed air goes through an after cooler in the machine which cools down the air, compresses it into water drops and drips into a water trap and can be removed. The left behind water that did not condensate can cause a variety of operational problems if it is not removed , such as freezing of outdoor air lines, corrosion in piping and equipment, malfunctioning of pneumatic process control instruments, fouling of processes and products and more. Use of air dryers significantly increases air quality and reduce maintenance costs.
