Before using a desiccant dryer, you'll need an oil-coalescing filter placed before it in the air system in order for it to work correctly.

In an adsorption dryer, also referred to as a desiccant dryer, most air flows over a bed of hygroscopic material—such as silica gel, molecular sieves, or activated alumina—which absorbs the water vapor from the air.

Membrane air dryers operate on the principle of migration. The compressed air to be dried is passed over a membrane that has a high affinity for water vapor. The water vapor builds on the membrane and migrates through to the opposite or low pressure, side.

In an adsorption dryer, also referred to as a desiccant dryer, most air flows over a bed of hygroscopic material—such as silica gel, molecular sieves, or activated alumina—which absorbs the water vapor from the air.

Adsorption air dryers use two towers with desiccant elements inside, which are able to easily absorb and release water within the air. As the desiccant spheres start the adsorption process, the air reaches a very low dew point and, when the desiccant material gets saturated, the dew point rises.

Meteorologists use the dew point temperature as a way to measure how dry or moist the atmosphere is. The dew point is the temperature the air would be if the atmosphere was saturated. The lower the dew point, the drier the air. The higher the dew point is, the more muggy the air feels.

The dew point is the temperature the air would need to be cooled in order for saturation to occur. For example, if the temperature is 5℃ and the dew point is 3℃, then the temperature would have to cool from 5℃ to 3℃ in order for the air to become saturated, assuming a constant moisture content in the air.

A refrigeration system and heat exchangers are used to reduce the temperature of compressed air to 2°C to 7°C which is also the dew point of the air.

The following information is required to select an air dryer: Maximum air flow in standard cubic feet per minute (SCFM). Inlet air pressure. Inlet air temperature. Ambient air temperature (and water temperature if condenser is water-cooled) Desired pressure dew point. Utilities required. Installation.

The most effective type of dryer is a twin tower, desiccant-type air dryer that has a pressure dew point of –70 ℃,but its cost is much higher than refrigerated air dryers.