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

Dust Suppression with an EXAIR Atomizing Nozzle

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An EXAIR Atomizing Nozzle used to minimize dust in the feed bowl of a cement mixer.

One of the most difficult aspects of handling and working with dusty materials is suppression of airborne contaminants.  Small particles can easily become a dust cloud, minimizing visibility and decreasing the quality of working conditions.  This then leads to lower productivity, low morale, and a missed opportunity to maximize the potential of personnel and equipment.

Our distributor in New Zealand recently assisted one of their customers facing this set of problems when working with cement and microsilica as it was poured into a mixer.  An exhaust fan was in place, but failed to extract the dust sufficiently, so a new approach was needed to minimize the dust.

 

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An AN2010SS No Drip Atomizing Nozzle provides the needed dust suppression in this application.

 

The solution was to use an EXAIR AN2010SS No Drip Internal Mix Atomizing Nozzle, shown above in the red box, to produce an atomized water mist.  The dust produced during pouring is captured by the small droplets of atomized water produced with this nozzle, reducing the dust and allowing proper use of the mixer.

 

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The 9218 Stay Set Hose positions the atomizing nozzle where it needs to be.

 

In order to position the nozzle exactly where it needs to be, an 18” Stay Set Hose, shown above with the red arrow, was used to position the nozzle.  This hose is built specifically to have “memory” of the desired position, allowing for quick, easy, and repeatable position of the nozzle attached to the hose.

This simple setup is controlled through a timer to ensure water and compressed air use realize maximum efficiency.  It’s an easy solution to a painful problem for this customer.

If you’d like to explore how an EXAIR solution can solve problems in your facility or application, please contact an EXAIR Application Engineer.

 

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

Taming The Dust Cloud With EXAIR Atomizing Spray Nozzles

Have you ever dropped one of your nice dinner plates on a tiled kitchen floor? And noticed how they seem to go in slow motion as they hurtle to their doom? I never cease to be impressed at how far some of the smaller pieces can go. I recently had to replace our oven, and I found broken dishware shards (and an impressive amount of trash scraps, pet toys, and ‘dust bunnies’) all the way against the back wall.

Curiously, as small as the pieces can be when a dinner plate meets its end, it started its life in even smaller pieces…as a fine ceramic powder, pressed into a mold and heated to a temperature that is WAY hotter than when the server at your favorite restaurant warns you that plate “might be hot.”

I’m writing about this because recently, I had the pleasure of assisting a maker of ceramic dishware with a messy little problem…this fine ceramic powder is moved from where it’s produced, to the various mold stations (dinner plates, salad plates, saucers, etc.) on a vibratory belt conveyor. The vibration keeps the powder loose and homogenous, both of which are extremely important to the molding & firing process. It also causes a cloud of dust to rise along the entire length of travel, and they wanted to minimize this. Their chemists had told the engineer who called me that they could live with a small amount of moisture, as long as it wasn’t enough to make the powder clump up – this would evaporate out at a point closer to the molds anyway.

This was an ideal application for the EXAIR Atomizing Spray Nozzles…they produce a fine mist of liquid that is precisely controllable…one Model AW1010SS Internal Mix, Wide Angle Round Pattern Nozzle was installed near the beginning of the line, and once they find out how long it takes the dust-suppression supplied by the misted water to evaporate away, they will install more nozzles accordingly.

EXAIR Atomizing Spray Nozzles are a perfect solution for dust suppression.

EXAIR Atomizing Spray Nozzles are a perfect solution for dust suppression.

EXAIR Atomizing Spray Nozzles are ideal for situations where you need a fine liquid mist and fine adjustment of the flow & pattern. With ninety models to choose from, we’ve got the one you’re looking for. Call me if you want to find out more.

Russ Bowman
Application Engineer
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