How Does a Desiccant Air Dryer Work?
It is virtually impossible to harness moisture free air for industrial use directly from the ambient environment. A failure to eliminate the excess moisture in compressed air generated for industrial use will alter the quality of process air and damage moisture-sensitive machinery.
This article highlights the effectiveness of using a desiccant air dryer in industrial air-drying operations.
What Is Desiccant?
A desiccant is a special adsorbent material with a high affinity for water. This special material has hygroscopic properties that allow it to maintain a dry immediate environment by pulling and holding water molecules within itself.
Types of Desiccant
Most desiccant materials are stable chemically but a few toxic and can only be used under special conditions. The most common types of desiccants include:
- Activated charcoal
- Calcium chloride
- Calcium sulphate
- Aluminosilicate minerals (zeolites)
Desiccants have found applications in both everyday domestic use as well as large scale industrial applications such as compressed air drying.
What Is a Desiccant Air Dryer?
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.
What Is Meant by Regenerative Desiccant Air Dryer?
The term “regenerative” is used to refer to an industrial desiccant air dryer that can renew its desiccant material by reversing the adsorptive process. Typically, regenerative desiccant dryers have paired desiccant packed towers that permit water absorption and material regeneration to occur simultaneously.
Twin Tower Desiccant Compressed Air Dryers
Twin tower desiccant dryers are essentially dual desiccant systems that constantly switch between absorptive and regenerative modes. Indicators detect the level of water saturation in each tower and automatically switch phase when appropriate.
How Do Desiccant Dryers Work?
This dryer type possesses two towers equally filled with hygroscopic materials. During routine operation, one tower is used to actively eliminate moisture from compressed air channeled through it while the other tower undergoes a reverse process where moisture is actively removed from to “regenerate” the desiccant material.
Once the desiccant in the absorptive tower is saturated and the material in the second tower is sufficiently dried, a control unit is used to automatically reverse their functions. With this phase change, the fully saturated desiccant tower then enters a regenerative mode while the freshly regenerated material in the second tower is used to remove the moisture in the supply air feed.
How to Regenerate Desiccant Beads
Regenerating desiccant material is done by eliminating the moisture it has accumulated during a cycle of compressed air drying. There are different ways of regenerating the hygroscopic materials used in air drying systems.
Hot Air Desiccant Regeneration
This method forces a stream of heated air through the water-saturated desiccant tower to eliminate the moisture within it. This drying technique requires a fan, and an electric heater to dry the desiccant.
Desiccant Regeneration Using Dry Compressed Air
Renewing desiccant using a portion of the freshly dried compressed air is energy-efficient and saves operators additional costs on utilities.
Desiccant Drying using Special Drying Systems
This air dryer system can simultaneously regenerate its desiccant and dry compressed at the same time. This air dryer has a rotating drum system where a quarter of the drum is involved in desiccant regeneration while the remaining portions are concurrently drying the compressed air.
Common Applications of Desiccant Air Drying Systems
Desiccant air dryers are most common in industrial applications that utilize compressed air. For example, the Oil and Gas Industry uses compressed air in almost all its operations from oil recovery to petroleum refining and transport. The equipment used in these operations are typically susceptible to moisture-related damage.
The use of a desiccant air drying system prevents the rapid wear and breakdown of moisture-sensitive components in most industries.
Where to Buy Desiccant Air Dryer Systems
Although there are dozens of air drying systems on the market, not all of them might be suited to your unique air-drying needs. Seek help from a trusted firm with extensive knowledge in air-drying solutions before purchasing an air dryer system for your industrial process.
NiGen has decades of experience in manufacturing compressed air dryers suitable for use across a broad range of industrial processes.
NiGen Has a Solution to Most of Your Process Air Needs
In nearly two decades of its existence, NiGen has established an enviable reputation for providing the most efficient and cost-effective compressed air drying solutions for its customers.
These air drying solutions are suitable for use across a broad range of industrial processes. Our high quality compressed air desiccant dryers are also available on a rental basis to cater to all your air-drying requirements.
Contact us online today for more information about our products and services.