Compressed Air Drying: The 3 Most Common Methods to Use in 2023
Compressed air dryers are the backbone of air compressor systems.
Moisture is always present in the atmospheric air. As this air is compressed, water is created in the air stream and this moisture content increases and mixes with the compressed air. Some moisture is acceptable but excess quantity of it can lead to serious problems such as corrosion, freeze-ups, and reduced performance.
That’s where compressed air dryers come into action!
These devices ensure that compressed air is clean, dry, and suitable for end-use application.
Think of it this way: a compressed air dryer is like the air traffic controller of your air compressor system. It manages the moisture content of air, ensuring that everything functions smoothly.
In this blog, we will be exploring the three most common methods of drying compressed air in air compressor systems. Whether you're an engineer, technician, or facility manager, this information will help you make informed decisions about the best drying method for your specific application and ensure that your compressed air system is working at optimum level.
The 3 Most Common Compressed Air-Drying Methods:
Method No.1 – Desiccant Air Drying Technology
Desiccated air drying is a popular method of removing moisture from compressed air in air compressor systems. The process involves removing the moisture content from the compressed air by passing it through a desiccant material.
There are two popular types of desiccant air dryers: solid desiccant dryers and structured desiccant air dryers. Solid desiccant dryers use a solid block of desiccant material to remove moisture from compressed air, while structured desiccant air dryers route compressed air directly through the solid desiccant, resulting in reduced energy costs, improved air quality, and longer maintenance intervals.
Benefits of Desiccant Air-Drying Technology
Continuous Operation:
Desiccant air dryers can operate continuously, making them ideal for industrial applications where a constant supply of dry compressed air is essential.
Reduced Energy Costs:
Desiccant air-drying results in reduced energy costs as there is minimal pressure drop during the drying process. This results in a more efficient and cost-effective air compressor system.
Low Maintenance:
Desiccant air dryers require low maintenance, as they have longer maintenance intervals compared to other air-drying methods. This results in lower operating costs and increased efficiency.
Environmentally Friendly:
Desiccant air dryers generate less dust compared to other air drying methods, making them more environmentally friendly and a safer option for occupational health.
Suitable Industries for Desiccant Air-Drying Technology
In the UAE, desiccant air-drying technology is used in a variety of industries, including petrochemical, oil and gas, construction, power generation, and food and beverage.
These industries require a consistent supply of dry compressed air for a wide range of applications, such as powering pneumatic tools, running production processes, and controlling the humidity in storage areas, with dew points down to -70°C / -100° F
Cerades™ is a solid desiccant designed by Atlas Copco that revolutionizes the design, efficiency and performance of desiccant dryers. Unlike conventional desiccant dryers, Cerades doesn’t produce dust leading to a better environmental and occupational health protection, and lower costs.
Method No.2 – Refrigerant Air Drying Technology
The second one on the popular compressed air-drying technology list are refrigerant dryers.
They consist of an air-to-air heat exchanger and an air-to-refrigerant heat exchanger. The compressed air is first pre-cooled by the outgoing cooler air in the air-to-air heat exchanger. Then, it is further cooled down to a temperature of approximately 3°C in the air-to-refrigerant heat exchanger, where the water vapor is partially condensed and removed.
In the next step, the compressed air is heated by the incoming air, which reduces its relative humidity. Refrigerant dryers, which come in water-cooled and air-cooled versions, are commonly used in compressed air systems to prevent water and corrosion.
Benefits of Refrigerant Air-Drying Technology
Energy Efficiency
Refrigerant air-drying technology is generally more energy-efficient than desiccant air-drying technology because it relies on cooling rather than heating to remove moisture from compressed air.
Compactness
Refrigerant air dryers are typically smaller and more compact than desiccant air dryers, making them ideal for use in applications where space is limited.
High Performance
Refrigerant air dryers are capable of achieving dew points of +3 °C to +7 °C, which is ideal for most applications that require dry compressed air.
Cost Effective
Refrigerant air drying technology is generally less expensive than desiccant air drying technology, making it an attractive option for many applications.
Suitable Industries for Refrigerant Air-Drying Technology
Refrigerant air-drying technology is ideal for use in manufacturing facilities, where dry compressed air is required for pneumatic tools and other machinery.
This technology is also commonly used in the oil and gas industry in the UAE, where compressed air is required for various applications like impact wrenches & running air-driven tools.
In the food and beverage industry, refrigerant air dryers are used to dry compressed air used in packaging and processing equipment, as well as in HVAC systems.
Method No.3 – Membrane Air Drying Technology
The last one of our lists is membrane air drying technology.
Membrane air drying technology uses a semipermeable membrane to separate the moisture from the compressed air. The compressed air is passed through the membrane, and the moisture is removed by diffusion.
Benefits of Membrane Air-Drying Technology
Dew Point Suppression
Unlike refrigerant and desiccant air dryers that provide a fixed dew point, membrane dryers deliver a dew point suppression.
Minimum to No-maintenance
Membrane dryers have no moving components, which means they don’t require substantial maintenance.
Energy Efficient
As there are no refrigerant units or heating/cooling systems involved, membrane dryers take up relatively less energy to function themselves.
Simple Design
The design of membrane dryers is very simple and reliable.
High Reliability
Membrane dryers have a long lifespan and are not affected by changes in temperature and humidity.
Suitable Industries for Membrane Air-Drying Technology
Membrane air drying technology is suitable for a wide range of applications in the pharmaceutical, food and beverage, electronic and textile industry.
Atlas Copco's SDR membrane dryers are a perfect solution for the railway industry, providing outstanding protection against moisture in rail vehicle systems even in the harshest weather conditions – as low as -40 °C and as high as +50 °C.