It is not a hidden fact that compressed air is never completely clean and dry. Just as drinking water needs to be filtered, compressed air also needs treatment before use. If we do not treat the moisture that’s present in air, it turns into liquid and creates problems inside the compressor system.
This is the main reason we use air dryers for air compressors. They are designed to remove water vapor and make compressed air clean and dry. Plus, the use of air dryers not only protects equipment but also improves the quality of work in different industries.
In this article, we will explain why air dryers are commonly used with air compressors.
Compressed air always contains moisture
When a compressor takes in air then it also takes in humidity from the environment. This humidity becomes concentrated as the air is compressed. The result is air with high water vapor content.
Once compressed air cools down, that vapor turns into liquid water. This liquid stays inside tanks, lines and tools. Even in small amounts, it can create problems like: corrosion, blockages and poor performance. Moisture is always present in compressed air. It cannot be avoided without a drying system.
Filters alone are not enough to keep air clean
Filters are designed to remove particles, oil and some liquid water. They are effective at point of use but… they cannot completely remove water vapor. That vapor stays in the system and later turns into liquid.
As filters provide clean air for a short distance but they do not stop moisture from spreading. This means that all parts are still at risk. Thus, for complete protection, filters need to work together with air dryers. The dryer removes vapor and the filter removes the remaining oil and particles.
How water vapor turns into liquid inside systems
Water vapor becomes liquid when the pressure and temperature are changed inside the compressor system. When compressed air expands quickly, it cools. So, this cooling forces the vapor to condense into liquid droplets.
Let’s take an example of dust collectors. When valves release compressed air, then rapid expansion causes mist and fog. That fog turns into liquid on collection bags and damages them.
The same effect takes place across many tools and machines. Every cycle of compression and expansion creates liquid water unless a dryer removes these vapors first.
Refrigerated air dryers work like a cooling process
Refrigerated air dryers are the most common type of air dryers. They are basically used in small workshops and large industries. They work by cooling the compressed air. As you know, when the air cools, then water vapor condenses into liquid. At this stage refrigerated dryers separate and drain this liquid.
The process is simple and reliable. Refrigerated dryers provide dry air suitable for many general applications. They are widely available and highly cost effective. For industries where extremely dry air is not required, refrigerated dryers are the preferred choice.
Regenerative dryers keep air dry through continuous cycling
When applications require very very dry air, then regenerative dryers are used. These dryers basically rely on desiccant material to absorb water vapor. They mostly use two towers filled with desiccant that work in cycles. While one tower dries the air, and the other regenerates by releasing trapped moisture.
Thus, this cycling between towers keeps the system working without interruption. This process makes sure the continuous supply of dry air. Regenerative dryers are more expensive than refrigerated ones. But they are very necessary in industries that demand high quality compressed air. Industries like painting, laboratories or pharmaceutical production cannot tolerate the small amount of moisture.
Desiccant pots provide dry air but need manual care
Desiccant pots are smaller plus simpler versions of regenerative dryers. That means they also use desiccant to remove water vapor. They are effective for single points of use or for small scale applications. Unlike regenerative dryers, they do not cycle automatically.
Moreover, desiccant pots need manual maintenance. They mostly come with an indicator that changes color when your desiccant is saturated. At this point, you need to replace or regenerate the desiccant. That’s why they are affordable and also simple but less convenient for continuous operations.
Dry air prevents rust and damage in machines
Moisture in compressed air always causes “corrosion” (rust) inside the compressor system (tanks, pipes or valves). Once this corrosion starts, it becomes very difficult to stop. Because this rust spreads and weakens the metal surfaces of your compressor. It not only shortens the life of your machines but also increases repair costs.
Therefore, dry air eliminates this risk. By removing water vapor, “air dryers” stop rust from forming in the first place. So, tools and systems remain reliable and clean. This protection is much needed for all types of equipment: from large compressors to small pneumatic tools.
Better air quality improves product finish and performance
Air quality has a direct effect on product results. For example: in painting or coating, even a small quantity of moisture can ruin your results. Similarly, in food and pharmaceutical industries, moisture leads to food contamination.
Also, dry air improves the machine’s performance. Like tools run smoothly, valves do not block or filters last longer etc. Thus, in every case, better air quality means higher output and fewer problems. And air dryers make this possible by delivering air that is both clean and dry.
Combination of refrigerated and desiccant dryers gives best results
Sometimes, in some applications, one type of dryer is not enough. At that point, you can get better results by combining two types of dryers (commonly refrigerated and desiccant).
For example: a refrigerated dryer can be used first to cool the air and remove most of the moisture. Then a desiccant dryer finishes the job by removing the remaining vapor.
This combination produces very very dry air that meets the strictest requirements. This is common in industries where the “highest standards of air quality” are necessary. Using both types together increases the efficiency and extends the life of the desiccant material.
Dry air protects long term efficiency of compressors
As you know, air compressors are expensive so they need protection. When moisture remains for a long time in the compressor system, it reduces efficiency. As water collects in lines, pressure drops and forces the compressor to work more harder.
Thus, air dryers keep the compressor system efficient by removing water vapor. Compressors run smoothly and use less energy. So, dry air is not only about protecting products today. But also makes sure that compressor continues to perform well for years.
Conclusion
Air dryers are not an extra part of compressor systems but they are a need. Because they keep moisture out, protect machines from rust and improve the quality of every result. Each type of air dryers, refrigerated dryers, regenerative dryers or desiccant pots have their own role. And sometimes the best results come when they work together.
Contact us today to get high quality air dryers and air compressor solutions for your industry.
