Working Principle

The refrigerated air dryer operates based on the principle of refrigeration dehumidification. It uses a fully enclosed compression refrigeration system to cool the compressed air discharged from the air compressor, causing a large amount of saturated water vapor and oil mist to condense into liquid droplets. After gas–liquid separation, the condensate is automatically discharged by a drain valve.

The high-temperature saturated compressed air enters the precooler, where it exchanges heat with the cold dry air returning from the evaporator, lowering its temperature before entering the evaporator of the refrigeration system. There, it undergoes a second heat exchange with the refrigerant vapor, cooling down close to the refrigerant’s evaporation temperature. During these two cooling stages, the water vapor in the compressed air condenses into liquid droplets and is carried into the air–water separator, where it is removed by the automatic drain. The cooled, dry compressed air then passes through the precooler again, exchanging heat with the incoming moist air to raise its temperature. As a result, the outlet air from the dryer has low moisture content (low dew point) and low relative humidity.

Because of its reliable operation, easy maintenance, and low operating cost, the refrigerated air dryer has become the preferred purification equipment for air compressor systems in various industries.

Product Features

The refrigeration and air systems are accurately calculated by experts, with design parameters having more than 20% margin.
The refrigeration compressor adopts internationally advanced rotary, scroll, piston (fully enclosed), or semi-hermetic screw compressors (above 30HP), featuring stable operation, low noise, reliable performance, energy efficiency, long service life, and IP54 protection (dustproof and splash-proof).
The heat exchangers and air-cooled condensers use high-quality copper tubes with pure aluminum fins or stainless steel plate heat exchangers, providing high heat exchange efficiency and compact structure. The shells are made of stainless steel or anti-corrosion carbon steel to prevent secondary air contamination.
Refrigeration control components are from international brands such as Danfoss (Denmark), Sporlan (USA), and Emerson (USA). They offer excellent performance and include functions such as throttling and pressure reduction via thermal expansion valves, capacity regulation via hot gas bypass valves, and protection against overcurrent, overload, and high/low refrigerant pressure.
The air–liquid separator combines cyclone separation with stainless-steel mesh demisting, ensuring complete separation, preventing secondary evaporation of moisture, and guaranteeing drying performance. It offers better performance than cyclone separators and lower cost than filter-type separators, providing high cost-effectiveness.
The water-cooled condenser uses high-quality low-fin copper tubes, slow water flow, and multiple passes for high heat exchange efficiency and long-term resistance to scaling.
Automatic drains are configured as required, offering efficient water removal and energy savings. Options include float-type, electronic timer-type, and zero air-loss types.
External rotor cooling fans feature large airflow, low noise, and long service life even under frequent start-stop conditions.
Pressure-bearing components are manufactured, tested, and inspected according to GB150-2024 (Steel Pressure Vessels) and GB151-1999 (Shell and Tube Heat Exchangers), and comply with the Pressure Vessel Safety Technical Supervision Regulations.
The equipment is reasonably designed for easy maintenance, features a heat-sprayed surface for rust prevention and aesthetics, requires no foundation for installation, runs smoothly without vibration, has a low maintenance rate, no consumables, low operating cost, and can operate continuously without supervision.

Operating Conditions and Technical Parameters

Inlet air temperature: Normal temperature type ≤ 50°C; high temperature type ≤ 80°C
Cooling method: Air-cooled (water-cooled)
Ambient temperature: ≤ 40°C (air-cooled)
Pressure dew point: 2°C–10°C (0.7 MPa)
Refrigerant: R22 or optional R134a, R404A, R407C, R410A (CFC-free, eco-friendly)
Inlet air pressure: 0–1.0 MPa (orders accepted up to 6.4 MPa)
Pressure loss: ≤ 0.02 MPa
Cooling water inlet temperature: ≤ 32°C (water-cooled)
Cooling water inlet pressure: 0.15–0.4 MPa (water-cooled)