Types of Air Dryers: Refrigerates vs Desiccant vs Membrane

Industrial applications demand clean and dry air without moisture for damage-proof operations. From pneumatic tools to packaging, compressed, dry and clean air is widely used in automotive, manufacturing, food processing and almost every product-based industry. While compressed air has wide applications, its inherent moisture content can damage the tools and equipment, so it requires a filtration system, which the Air Dryer Manufacturer provides. Air dryers are an essential part of using compressed air as they remove the water content and contaminants from the air, ensuring the whole mechanism is free from corrosion-causing moisture. In this blog, we will explore the three main types of air dryers, mainly, refrigerates, desiccants and membranes. Each of these types has its strengths, abilities, usability and advantages. Let’s compare each of them and which applications suit the best.

Understanding Key Parameters

Before we begin the comparison, let’s understand key parameters first. These parameters are considered by an air dryer manufacturer during the design stage. Here are these:

• Flow Rate Capacity: The flow rate is measured in terms of CFM (cubic feet per minute). It indicates how much an air dryer can process air per unit time. Using underpowered or overpowered can lead to operational inefficiency.
• Dew Point: In air compression systems, dew is a crucial indicator as it determines the presence of moisture. The lower the dew point, the lower the moisture content present in the air. In technical terms, it is the temperature at which water is fully saturated and turns into liquid. The air dryer lowers the dew point of air to at least 20°C from ambient temperature so that it prevents moisture buildup.
• Other Factors: Energy consumption, Use Case and Minatainance.

Comparing Each Type

1.  Refrigerated Air Dryers

In refrigerated air dryers, the air is cooled to 3-5°C, a temperature at which is condensed so that can be easily drained out. After the water content is removed, the air is again reheated and sent downstream. It is suitable for general purpose manufacturing, automotive, packaging, and medical for clean and high air quality. It delivers consistent dry air, consumes low energy compared to other types and is easier to maintain.

2.  Desiccant Air Dryers

Desiccant is a drying agent, like silica gel or activated alumina with a high capacity to absorb moisture from the surroundings. The water molecules deposit on the surface and don’t get absorbed. The saturation chamber which contains the desiccant is isolated, and reheated to release the moisture so that the desiccant material can be reused. The twin tower mechanism is used to separate regeneration and air drying. It can deliver ultra-dry air between -40 to – 70°C, hence can be used in critical applications where there is cold surrounding. Suitable for sensitive environments like electronics, oil & gas, laboratories and pharmaceuticals.

3.  Membrane Air Dryers

These are compact and energy-efficient air dryers as it doesn’t require electricity to operate. The hollow membrane fibres use a selective permeation method which allows water vapours to pass through it while blocking the dry air. It is compact and lightweight, has no moving parts hence requires low maintenance and light capital investment. Suitable for point-of-use applications, these dryers can lower the dew point between a range of -10 to -40°C. Used in medical systems, portable air compressors, low-flow industrial applications and areas with limited power supply.

Conclusion

The air dryer is necessary to dry out the inherent moisture content from compressed air, an essential preventive method to ensure equipment and process safety. Removing moisture content from the air lowers the dew point and improves the air quality required in designated processes. Air Care Equipment is a trusted air dryer manufacturer, supplying three major types of air dryers- refrigerated, desiccant and membrane air dryers. Each type ha sits own advantages and dedicated application in various industries.