Refrigeration air dryers operate on the principle of cooling air to near-freezing temperatures in order to effectively remove moisture. Once the air is cooled, it is then reheated by the incoming compressed air, achieving a temperature approximately 10°C below that of the incoming air under standard operating conditions.

The system is composed of an advanced air drying unit featuring a centrifugal separator, as well as a sophisticated refrigeration circuit. This circuit includes key components such as the compressor, condenser, receiver, a volume liquid accumulator containing refrigerant, and an evaporator. 

The air drying unit itself incorporates two types of heat exchangers: an air-to-air heat exchanger and a refrigerant-to-air heat exchanger, both working in harmony to optimize moisture removal.

At the core of this system lies the heat exchanger, it efficiently transfers heat between the incoming compressed air and the refrigerant, optimizing moisture removal and enhancing system energy efficiency.

Air Cycle
Compressed air enters the pre-cooler through the air inlet for initial cooling, then proceeds to the evaporator for further cooling by the refrigerant. The cooled air passes through the moisture separator, where condensate is automatically discharged. Finally, the dry air returns to the pre-cooler to regain its temperature before exiting the system through the air outlet.  

Refrigerant Cycle
The refrigerant, initially a high-temperature, high-pressure gas, passes through the compressor before being condensed into a high-pressure liquid by either an air-cooled or water-cooled condenser. Impurities are filtered out by the drying filter. The refrigerant then undergoes expansion through a throttling device, transforming into a low-temperature, low-pressure semi-liquid, semi-vapour state. It enters the evaporator, where it absorbs heat from the incoming hot compressed air, completing the cooling process. The refrigerant then returns to the reservoir and is eventually recirculated to the compressor.