Types Of Compressed Air System Dryers

Many times, when discussing product selection with a customer, we commonly reference supplying as clean and dry air as possible to promote peak performance. In iron piping systems for example, when moisture is present, rust can develop which can reduce the performance of end use compressed air operated devices like air tools or cause issues on the exhaust side as you could exhaust unwanted mist onto a surface, like in a painting operation.

Example of a desiccant dryer

Typically, an efficient and properly installed industrial compressed air system will include some type of dryer to remove any moisture that may be present in the supply.

Let’s take a look at the various types of dryers available.

Refrigerant and desiccant dryers are two of the more commonly used types of dryers.

Refrigerant based systems have several stages. The compressed air first passes through an air to air heat exchanger  which initially cools the air. The air is then delivered to an air to refrigerant exchanger where an external source of liquid refrigerant further cools the air and sends it to a separator, where the water vapors condensate and are removed through a drain trap. Now that the air is dry, it is then cycled back to the air to air exchanger where it is heated back to ambient temperature and exits the system.

Desiccant dryers typically incorporate 2 tanks containing a porous desiccant which causes the moisture to sort of “cling” to the surface. In these systems, compressed air flows through one tank, while, using it’s own regeneration cycle, heated or unheated air is blown through the desiccant in the other tank to remove the moisture and dry the air.

Membrane Dryers are typically used at the end use product. These types of systems utilize membranes to dissipate water vapor as it passes through the material, while allowing a small amount of the dry air to travel the length of the membrane to sort of “wipe” the condensate and remove it from the system.

Deliquescent Dryers use a drying agent which absorbs any moisture in the air. As the vapors react with the desiccant, like salt, the desiccant liquefies and is able to be drained at the bottom of a tank. These are the least expensive dryers to purchase and maintain because they have no moving parts and require no power to run.

When a dryer is being considered for a particular setup, there are 3 common reference points used when determining the dryers rating – an inlet air temperature of 100°F, supply pressure of 100 PSIG and an ambient air temperature of 100°F. Changes in supply pressure or temperature could change the performance of a particular dryer. You want to follow the manufacturer’s recommendations when dealing with variances as they will typically provide some type of conversion.

For help with this or any other topics relating to the efficient use of compressed air, please give us a call, we’d be happy to help.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Heated Desiccant Dryers image courtesy of Compressor1 via creative commons license

Custom Solutions For Conveying Dry Material

The ideal solution for conveying large volumes of material over long distances.

EXAIR’s Line Vac compressed air operated conveyors have no moving parts or motors to wear out, providing a maintenance free way to move dry material from one location to another. We offer several different types and sizes of Line Vacs like our Standard Line Vacs, available from 3/8″ up to 5″  or our Threaded Line Vacs, with NPT threaded connections up to 3″. The Heavy Duty Line Vac are constructed of Hardened Alloy for superior abrasion resistance, available in sizes from 3/4” to 3”, smooth and threaded connections or the Light Duty Line Vac commonly used for smaller volume, shorter distance processes, with sizes from 3/4″ to 6”. We even offer Sanitary Flange Line Vacs from 1-1/2″ up to 3″ for processes requiring frequent cleaning. All of these products are in stock, ready to ship from our factory here in Cincinnati, Ohio.

For over 34 years, EXAIR has been manufacturing Intelligent Compressed Air Products and we understand that there may be “special” cases where a stock product isn’t going to fit a specific need or requirement. What sets us apart from our competition is that we are able, with a little help from the customer, to engineer and manufacture custom made products, like the Line Vac Conveyors, to fit the specific demand of a unique application.

A few examples are shown below:

Flanged design, easy to install


This special 3/4″ Stainless Steel flanged Line Vac is being used to remove acidic vapors after a silicon wafer etching process. The flanged design allowed the user to direct mount to the machine, eliminating the need for other expensive modifications.

 

 

 

Chemical resistant construction for washdown areas

 

 

A customer was needing a special Line Vac for a chloride wash area due to the aggressive chemicals. We were able to make a custom 1-1/2″ Line Vac in PVDF construction for corrosion resistance and QF flanges for easy maintenance and cleaning.

 

 

 

Custom funnel design for small, granulated material like sugar or salt

 

This special funnel shaped Line Vac is being used in a a small packet filling operation. The unique design assured for a clog free process by keeping the granulated material moving through the tube.

 

 

 

 

 

Miniature size for confined workspaces

 

A company was needing a miniature version of a Line Vac to remove microscopic debris in an integrated circuit chip making process. The barb fittings allowed for easy installation into the small work place.

 

 

 

 

 

These are just a few examples of how we are able to meet the demands of a wide variety of extraordinary processes. Whether you are looking to move “common” materials like plastic pellets or maybe something “off the wall”, chances are we have the resources to provide an engineered solution to fit your need. Our application engineers are standing by, so give us a call and let us put our expertise to work for you!

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN