Taking your time to understand how a desiccant air dryer can help determine if it is the right type of dryer for your compressed air application. But before delving deeper into our discussion topic today, it is essential to take a step back and know why your compressed air system needs dry air in the first place.
Well, the dryness of air is formally measured by its dew point. The lower the dew point, the dryer the air. That brings us back to the question; why do compressed air systems need dry air? In a nutshell, this could be because the end process or product is moisture sensitive.
Some applications, like the powder coating process or pharmaceutical, food, and electronics products and even packaging, are particularly sensitive to excess water vapor in the compressed air stream. Failure to dry the air sufficiently could lead to a botched process or unusable product. This is the last thing you want to make do with.
Even when no end product is being produced, tools and instruments used in many applications often require air to be dried to a certain level to work well, or even to work at all. When this is the case, you will certainly need a desiccant air dryer.
So, how does the desiccant air dryer work? For starters, compressed air contains contaminants that can adhere to the surface of desiccant beads. This decreases the efficiency of the desiccant by reducing the amount of moisture it can absorb over time.
The thing with pre-filtration is that it minimizes contamination of the desiccant by removing particulates from the air stream before the air reaches the desiccant bed. Minimized contamination has the potential to extend the life of the desiccant beads, which can reduce operating costs by requiring them to be replaced less often.
To continuously provide dry air downstream, a desiccant air dryer needs to collect moisture from the compressed air stream onto the desiccant. It should also release moisture from the desiccant beads to the outside air. This part of the process is called regeneration, and the reason desiccant dryers are sometimes called regenerative dryers.
Desiccant dryers manage the process of drying air and regenerating desiccant by using paired towers, coordinating adsorption and desorption between the two towers by cycling through a series of stages. Of course, there is a lot more you need to know about a desiccant air dryer than what’s included in this simple guide.
