4 Types of Compressed Air Dryers For Choice

Pneumatic air dryer is essential for most industries. Compressed air supplies power for many industrial applications. It is an integral part of many companies’ production processes. That’s why pure, clean air is vital. Operators rely on compressor air dryer systems to achieve optimum operation. We often need to control water vapor in the compressed air system. So how many types of pneumatic dryers are there?

What is A Pneumatic Air Dryer?

Compressed air always contains water vapor and other forms of moisture. This is harmful to our pipes, tools, and equipment. They can lead to corrosion, control failures, and equipment failure. Compressed air dryers remove water vapor and moisture content. So this is the function of an air dryer in a pneumatic system. It is part of the after-treatment equipment for air compressors.

What Are The Different Types of Pneumatic Air Dryers?

The task of a pneumatic dryer is to remove water vapor from the compressed air. At the same time, lower the dew point. There is a wide range of air compressor dryers on the market. The following is an overview of the six main types of compressed air dryers. They can be suitable for most industrial applications. We will also introduce the working principles of these pneumatic dryers.

pneumatic air dryer

(1) Refrigerated Pneumatic Dryer

What is a refrigerant dryer? As the name implies, it is freezing and drying. It is the process of “freezing” and “drying” the air. Finally, discharge clean air and drives the compressor to work. It is a part of a pneumatic system. Refrigerated compressed air dryers are highly efficient. And it has low purchase and maintenance costs. They can remove up to 90% of the water content of the air.

The refrigeration dryer is based on the principle of freeze-drying and dehumidification. The compressed air passes through an evaporator and is cooled down here. This is because the liquid refrigerant absorbs the heat from the air. Then the water, oil, and impurities form a liquid form. They are then drained through an automatic drain. Finally results in clean compressed air.

There are also many different types of refrigerant pneumatic dryers. Firstly, it contains both average temps. The former generally has an inlet air temperature of 45°C. The latter is generally 80°C. Secondly, the refrigerant dryer also includes air-cooled and water-cooled. The former is generally a small dryer. The latter is generally a large dryer. Thirdly, it comes in different pressures, such as low, medium, and high. Fourthly, the refrigerated dryer also includes cycling and non-cycling types. VSD air dryers are also available. In addition, it also includes carbon steel and stainless steel dryers. Above are the many types of refrigeration pneumatic dryers.

(2) Pneumatic Desiccant Dryer

Regeneration desiccant dryer removes water using adsorbents. Common adsorbents are alumina, silicone gel, and molecular sieves. Adsorption air dryer achieves lower dew points compared to refrigerant dryers.

The desiccant air dryer bases on the pressure shift to achieve the effect of dryness. This is because the capacity of the air to hold water vapor is inversely proportional to the pressure. A portion of the air is relieved of pressure after drying. Then they surge up to atmospheric pressure. This pressure shift makes the air drier and drier. Then let them pass through the desiccant beads layer. The moisture in the desiccant is absorbed. The two adsorption towers work in a cycle. The dry air is continuously delivered to the customer.

There are also many different types of desiccant pneumatic dryers. Firstly, we can distinguish it according to the regeneration method. It includes a heatless air dryer and a micro-heated absorption dryer. The former does not have an external heater. Therefore the air consumption is high. The latter adds an external heater. So it has a relatively small regenerative gas consumption. In addition, it also includes the blower purge desiccant dryer and HOC-type air dryer. And there is also the zero air-loss desiccant air dryer. Its regeneration air consumption is zero. So these are the types of desiccant pneumatic dryers.

(3) Combination Type Compressed Air Dryer

The combination dryer is a new one of the pneumatic air dryer types. It consists of a refrigeration dryer, an adsorption dryer, and a compressed air filter. Firstly, the air enters the refrigerant dryer for freezing and water removal. The dew point is reduced to below 10°C. Then they enter the compressed air filter. The oil content of the air is reduced. Finally, it enters the adsorption dryer for deep drying. The dew point temperatures can be -40°C and -70°C.

(4) Membrane Air Dryer

The membrane dryer is also a new type of pneumatic air dryer. It has a hollow fiber ultrafiltration delicate membrane tubular inside. Because of the difference in permeability of the components in the compressed air to the membrane, it can achieve air-water separation. This brings in dry compressed air.


It is different from the traditional pneumatic dryers. It is eco-friendly and energy efficient. It does not require a power supply. Moreover, the membrane dryer is not affected by the ambient temperature. The dew point of the air outlet can be adjustable according to the requirements. Thus it can meet the needs of different working conditions. It is mainly used in industrial control, pharmaceutical technology, food processing, technical research laboratories, and other applications.

So above is the introduction of different types of pneumatic dryers. For more information, welcome to contact Lingyu Dryer!