Two main Air dryer types
The two main types of compressed air dryers are refrigerated, desiccant in Dream Compressor’s air treatment products. It is important to understand how each drying technology works to learn which is best for your application.
Refrigerated dryers work by cooling the air to low temperatures and condensing much of the water vapor. It is not possible to achieve dew points below freezing with a refrigerated dryer. Optimally designed refrigerated dryers can produce air with dew points to approximately 36°F (2°C). Since some water vapor is left in the air, these dryers should not be used in water-sensitive applications.
Desiccant dryers pass the compressed air over a bed of desiccant material which absorbs water vapor molecules. When the bed capacity is nearly saturated, the air flow is switched to a second bed of desiccant material. The first bed is then regenerated. Timers or dew point monitoring equipment can be used to control the regeneration phase. Desiccant dryers can deliver air at consistently low dew points, typically -40°F/°-40° C or less. This technology is a good choice when the compressed air is subject to freezing conditions. There are two types of desiccant dryers: heated and heatless. Heated desiccant dryers use heat to remove water vapor from the desiccant material not in use at that point in the cycle. These dryers need large amounts of steam or electricity to operate. Heatless desiccant dryers use the dry air generated by the dryer to remove water vapor from the desiccant material. The major advantage of this technology is the reduced dependence on excessive outside services (e.g., steam, electricity, or gas) for heat. A regenerative desiccant dryer can be conveniently located near the point-of-use to deliver dry compressed air at dew points to -100°F (-73°C). Heatless desiccant dryers are ideal for delivering instrument quality air for critical applications.
