what is Desiccant dryer?

Desiccant or adsorption dryers are the most commonly used for outdoor instrument air system desiccant materials are hydroscopic materials.

Desiccant materials are chemicals that readily  take up and retain moisture on their surfaces.

A desiccant is a substance that absorbs water. It is most commonly used to remove humidity that would normally degrade or even destroy products sensitive to moisture.

List of desiccants:

• Activated alumina
• Aerogel
• Silica gel
• Sodium
• Sodium chlorate
• Sodium chloride

when moistured air  is in contact with the desiccant ,an equilibrium condition is established in which the relative humidity of the air determined the  degree of saturation of the desiccant particles. the greater the relative humidity, the more moisture is absorbed up to 45% and limit mentioned.

Desiccant dryers are filled with a solid desiccant, such as a activated alumina and silica gel, which removes water vapour as the air passes through the desiccant bed. the desiccant become wet in the process and a moisture must be removed and  the desiccants  must be regenerated.

Desiccant air dryers work on a different principle they adsorb moisture from the air stream and onto a desiccant material in a reversible process. They produce low dew points, so they are a good choice in subfreezing conditions or when processes require extremely dry air. Two types are heatless and heated.

Refrigerant is a compound typically found in either a fluid or gaseous state. It readily absorbs heat from the environment and can provide refrigeration or air conditioning when combined with other components such as compressors and evaporators.