A desiccant air dryer for compressed air uses special drying agent beads like silica gel and activated alumina to absorb water vapor from an air stream. These air dryer units are often regenerative so that the drying agent doesn’t need replacing in order to provide vapor-free compressed air consistently.
A desiccant dryer or an adsorption dryer is a piece of industrial equipment that uses desiccant materials to eliminated water from the air channeled through it. A standard desiccant dryer system uses a two-tower set up to ensure a continuous air drying cycle. Desiccant dryers lower the dewpoint of compressed air by adsorbing water vapor onto the surface of a desiccant. The process of adsorption begins as the water vapor, which is more highly concentrated in the compressed air stream, moves into an area of lower water vapor concentration in the pores of the desiccant. A compressed air dryer is a piece of equipment designed to separate water vapor or moisture (de-humidify) from industrial process air. In the typical system, a compressor draws in humid air and compresses it, which raises the air temperature and then cooling the air condensing water vapor out of the unit.
A desiccant air dryer system consists of two towers, one for drying the air and the other for regenerating the desiccant. The drying tower contains a porous desiccant material that inhibits water molecules as compressed air from the inlet passes over it. A less common variant, the single tower desiccant air dryer, comprises a single tower containing a desiccant material that dries air coming in from the environment. Single-tower dryers also contain no mechanical parts and do not require electricity to operate. They are suitable for use in hazardous and corrosive environments. These instrument air dryers use a desiccant material, hygroscopic substances that exhibit a high affinity for water as the de-humidification agent. These types of compressed air dryers achieve a low dew point, making them suitable for use in colder climates and industries that require super dry air.