August 5, 2024
Estimated reading time: 2 minutes
Compressed air contamination doesn’t simply disappear during the air compression process – even if you’re using an oil-free air compressor!
Atmospheric air is naturally contaminated; in addition, there are a variety of contaminants that are typically found within a compressed air system itself. These include water vapor, oil vapor, liquid oil, liquid water, pipe scale/rust, water aerosols, oil aerosols, microorganisms, and atmospheric dirt. The presence of these contaminants means that air purification equipment (also known as air treatment products or compressed air ancillary products) is required to reduce, or wholly remove, the contamination from the compressed air.
How can you clear your air of water, oil and dust?
The introduction of unwanted substances, such as water, oil and dust, into your compressed air system can impair production results and even increase costs. Not to mention, your end uses will be affected by the lower quality of air. Luckily, there are several air treatment options available for clearing your compressed air of unwanted substances.
Depending on your end-use, some (or all) of these items might be necessary for your compressed air installation.
To control contamination and condensate, you should treat your compressed air by following three basic steps:
- Dry,
- Filter,
- Separate.
The air treatment products associated with the above steps are:
After-cooler
Compressed air is very hot after it’s compressed. An after-cooler is used to lower this temperature, which in turn reduces the water content.
After-coolers are frequently included as standard equipment for compressor installations and should be placed directly after the compressor.
The heat exchanger cools the hot air and then routes most of the condensation water away from the system as quickly as possible.
Drains
Available in different types such as automatic, manual, and no-air-loss, a water separator allows the condensate that is collected from the system to automatically drain away - thus preventing collected condensate from re-entering the compressed air system.
With proper sizing and selection, a water separator can achieve an 80-90 percent efficiency in separating condensation water from the compressed air. The remaining water flows with the compressed air as water vapor into the air receiver.
Filters
A correctly installed coalescing filter, together with a suitable pre-filter, can reduce the quantity of oil in compressed air to approximately 0.01 mg/m3. With an activated carbon filter, the quantity of oil can be reduced to 0.003 mg/m3.
Dryers
Many systems require a much higher degree of air drying than filters and water separators can provide. In that case, a dryer is used to reduce the moisture levels below the point where condensation can occur later in the system.
For most systems, this would mean a refrigerated dryer that removes the water by cooling the air to a temperature near freezing. When even dryer air is needed, a desiccant type dryer is required.
This type of dryer reduces the water content by adsorbing the water onto specially designed media.
Oil/water separator
Oil/water separators are an easy and cost-effective solution for meeting new and more stringent laws with regards to handling environmentally hazardous oil waste in your condensate.
Absorption media traps oil to produce clean drainage water.
Why is compressed air treatment important?
While each compressed air installation is unique, one thing remains consistent across all systems: the necessity of properly treating compressed air. By allowing moisture, dirt, and particle matter to stay in the system, you are risking a decrease in system efficiency, as well as increased downtime for extended repairs and maintenance of the equipment the air powers.
However, by ensuring that your compressor installation utilizes the correct air treatment products, you can simultaneously reduce the maintenance and energy costs of your application. And as an added bonus, you’ll have the peace of mind that you are setting up your compressor system for a longer, productive lifespan.
Filters play a crucial role in the proper treatment of compressed air. In this interactive e-book on compressed air filters you will learn everything on contaminants and which filters offer you optimal protection.
Do you have specific questions or would you like to discuss which filter is the right solution for your business? Click the button below to get in touch with an expert!
Related Topics and Project
Air dryers Aftercoolers Oil Water separators Filters Water separators Refrigerant dryers Desiccant air dryers
