What Are Desiccant Dryers Most Useful For?

Inside a pneumatic system, there are compressors designed to pull in ambient air, which will always have at least a small amount of water vapor in it. The compression process raises the temperature of the air, but also the dew point and the air’s capacity to hold water. This can be problematic, because the presence of liquid water inside a pneumatic system can result in corrosion or the growth of bacteria or mold, leading to decreased effectiveness and efficiency.

This is where air dryers come into the picture. By removing the moisture from the air in a pneumatic system, you can avoid the potential problems associated with liquid water in the system as the compression process occurs.

There are several main types of air dryers. Today we are focusing specifically on one of these types: desiccant dryers. So, how do desiccant dryers work in Wisconsin facilities like yours? Let’s take a look.

What to know about desiccant dryers

Desiccant air dryers are designed to extract moisture from the air stream and divert it to a desiccant material. They create low dew points, which makes them ideal for use in conditions below freezing, or if you require very dry air for your particular application.

There are two primary types of desiccant air dryers: heatless and heated.

Heatless desiccant air dryers feature a desiccant material in a pair of tanks located right next to each other, known as the regenerating tower and the drying tower. The air packed with moisture flows first into the drying tower, where it binds to the desiccant material. Extremely dry air then exits the dryer. This process raises the air temperature by up to 20 degrees Fahrenheit. The air then moves to the regenerating tower, where the compressed air expands to atmospheric pressure as water gets pulled off the desiccant, thanks to the higher air temperature present. The moist air is discharged from the system.

In a heated desiccant dryer, there is a heater located inside the circuit. Here again, there are two towers designed to remove moisture from the air and then regenerate the desiccant that was used. Valves divert about eight percent of the air that exits the drying tower and put it through a heater, which heats up and dries the air before it passes over the regenerating tower’s desiccant material. The moist air will then be discharged to the outside.

If choosing between a heatless or heated desiccant dryer in Wisconsin, you will need to consider costs and efficiency. Heated dryers use approximately 50 percent less compressed air, but they can also take a lot of electricity to operate. You should carefully research the specific applications you’re interested in before you make a decision.

Interested in learning more about the various types of air dryers for pneumatic systems? Wenniger Compressor Co. can help. We encourage you to contact our air compressor repair shop with any questions you have, and we will be happy to provide you with assistance as you make your desiccant air dryer selection.

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