Compressed air dryers might be necessary if your facility uses compressed air. Here is the information you need to know about different types of compressed air dryers.
An air compressor takes the surrounding air, named also ambient air, to produce compressed air. In addition to oxygen, ambient air may also contain other gases and vapor, particularly in humid environments.
There are three typical types of compressed air dryers: chilled air dryers, deliquescent air dryers, desiccant air dryers, chemical air dryers, and membrane air dryers. This article will go into more detail about the various types of air dryers that are available for use.
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What is a Compressed Air Dryer?
Dryers for compressed air are devices that take the water vapor out of compressed air.
They are essential when using air compressors because they concentrate different air constituents, raising the dew point and resulting in condensation that could harm your facility and result in freezing, corrosion, and other issues.
Types of Compressed Air Dryers
The most commonly used air dyer systems are described below:
- Refrigerated air dryers
- Deliquescent air dryers
- Desiccant air dryers
- Chemical air dryers
- Membrane air dryers
Refrigerated Air Dryers
Heat exchanges from the air and the refrigerator are used to power these dryers. The air-to-air exchange lowers the temperature of the warmer incoming air by exchanging cool, dry air for the incoming, hotter air.
After entering the air-to-refrigerator exchanger, where liquid refrigerant is used to lower the temperature to 3 degrees Celsius, the incoming air is then used. The moisture in the liquid water condenses as a result, drains off as a result, and the cycle is restarted by the cool outgoing air.
Deliquescent Air Dryers
The absorptive mechanism in these dryers aids in removing moisture from the air that passes through them. Deliquescent dryers also use hygroscopic salt tablets that need to be changed when saturated.
In dangerous, remote areas that require dry, pressurized air, deliquescent dryers can be used successfully. Landfills, the wood and asphalt manufacturing industries, and other settings are examples of applications that profit from the use of deliquescent dryers.
Desiccant Air Dryers
As the name implies, this kind of compressed air dryer operates by forcing compressed air through a compartment that is packed with desiccants. Desiccants are substances with innate moisture-absorbing qualities.
There are typically two identical desiccant chambers in a desiccant compressed air dryer, or regenerative dryer as it is also known. While the other compartment, which is also filled with desiccant, is being regenerated, the unit will automatically use one compartment to dry compressed air.
Automatic use of the two compartments alternates, ensuring a steady supply of dry compressed air. Additionally, because the unit self-regenerates, maintenance is made simple. The regeneration process can be carried out using heat, compressed air, vacuum, or a combination of these technologies.
Chemical Air Dryers
These dryers remove moisture from pressurized air using hygroscopic materials. A typical setup is a drying unit that draws moisture from the air stream passing through it using calcium chloride or lithium beads. The lifespan of the drying material is also frequently extended by the integration of premium coalescing and particulate filters.
For combining moisture-sensitive chemical manufacturing and food processing applications, chemical dryers are a good option.
Membrane Air Dryers
As a filtration system that integrates with existing compressed air systems, membrane dryers remove both contaminants and water vapor. A bundle of hollow fibers made of a membrane made specifically to attract water vapor is passed through by compressed, humid air.
The thinner the membrane, the more moisture diffuses through to the outside, where it is removed, and the more pressure there is in the compressed air system, the more effectively the membrane dryer works. This system is space-efficient and runs without the use of refrigerants.
How Do Compressed Air Dryers Work?
Dry-air dryers, including compressed-air dryers, are included in this category. They create dry process air with a low dew point by expanding compressed air to atmospheric pressure. The dryer raises the temperature of this air to the desired level.
Desiccants are not needed for compressed-air dryers. After passing through the material and absorbing moisture, the heated air is expelled along with the entrained moisture.
Although the cost of compressed air is high, compressed air dryers themselves are reasonably priced. As a result, these systems are typically only appropriate for drying small amounts of granulation.
The operation of these systems requires compressed air that is dry, oil-free, and water-free. Compressed air dryers function on the fundamental tenet that as it expands, they lower the dew point. Depending on the initial dew point of the compressed air, these systems can reach dew points of -20°C or lower.
Water vapor is a constant in the air. The amount of water that air can hold is decreased when it is compressed, and pressure and volume also rise. This is like a sponge in that it can hold some water when it is expanded but releases the water when it is compressed.
The temperature rises as a result of air compression, increasing the pressure dew point. The lowest temperature that can be reached for compressed air without causing entrapped moisture to condense is known as the pressure dew point.
The entrained moisture condenses as the compressed air cools down more in the compressor, which lowers the absolute humidity of the air. The pressure of this air is subsequently decreased before it is fed into the production facility’s internal compressed-air distribution system, resulting in a decrease in pressure dew point.
Following further expansion in the compressed-air dryer, a heater, and finally the granulate, this pre-expanded air is fed to it.
Conclusion
Any air compressor tool needs a compressed air dryer. They purify and dry the compressed air using various techniques, getting rid of dirt, oil, and water vapor. Your applications can be powered by clean, dry air, which also helps prevent corrosion and control issues.
Whatever your requirement, it is always a good idea to protect your compressor with an air dryer. They’ll assist you in avoiding the deterioration of parts and the recurring expense of maintenance, from corrosion and contamination to control malfunctions.
FAQs
Is An Air Compressor the Same as An Air Dryer?
There is a lot of moisture produced by air compressors, and while the extra moisture can be drained, it cannot be completely eliminated. It can be difficult to remove water that frequently remains as an aerosol or vapor. Air dryers can help remove the excess moisture in the air from air compressors.
What Air Dryer is the Most Efficient?
Twin-tower, desiccant-type dryers are the most effective in the removal of moisture from the air and typically are rated at a pressure dew point of –40°F.
