Difference between revisions of "Compressed Air Dryers"

A deliquescent dryer typically consists of a pressure vessel filled  with a hygroscopic media that absorbs water vapor. The media gradually  dissolves—or deliquesces—to form a solution at the base of the pressure  vessel. The liquid must be regularly drained from the vessel and new  media must be added. The media is usually in tablet or briquette form.

Deliquescent  dryers have no moving parts and don't require electrical  power for  operation. Common applications therefore often involve  remote,  hazardous, or mobile worksites. Deliquescent dryers are used for  removing water vapor from compressed air, natural gas, and waste gases  such as landfill gas and digester gas.

The  term  [[Desiccant Dryers]] refers to a broad class of dryers. Other  terms commonly used are regenerative dryer and twin tower dryer, and to a  lesser extent [[Absorption Dryers]].

The compressed air is  passed through a pressure vessel filled with an absorbent media such as  activated alumina, silica gel, molecular sieve or other desiccant  material. The desiccant can bring the dew point of the water vapor in  the air down to −40 °C (−40 °F) or below. This means that the air will  not condense (deposition)  water until it is cooled to −40 °C (−40 °F).  In practice, two cylinders  with desiccant are used; one is drying the  air, while the other vessel  is being regenerated. The switching of the  vessels and the regeneration  sequence is typically done automatically  via solenoid operated valves. The regeneration of the desiccant vessel can be during three different methods:

Membrane dryer refers to a dehumidification membrane that removes water vapor from compressed air.

Typically,  the compressed air is first filtered with a high-quality [[Coalescing  Filters|Coalescing Filter]]. This filter removes liquid water, oil and  particulate from the  compressed air. The water vapor–laden air then  passes through the center  bore of hollow fibers in the membrane bundle.  At the same time, a small  portion of the dry air product is redirected  along the outside surface  of the fibers to sweep out the water vapor  which has permeated the  membrane. The moisture-laden sweep gas is then  vented to the atmosphere,  and clean, dry air is supplied to the  application. The membrane air  dryers are designed to operate  continuously, 24 hours per day, 7 days  per week. Membrane air dryers  are quiet, reliable and require no  electricity to operate.

* Drying air for use in commercial or industrial processes that demand dry air

:*Telecomm industry (pressurizes its underground cables to repel moisture and avoid shorts