When starting the air compressor, should the refrigerant dryer be turned on first?

The Correct Startup Sequence for Air Compressors and Refrigerant Dryers

In industrial compressed air systems, the air compressor and the refrigerant dryer are core components that work in close coordination. Regarding the question of whether to start the refrigerant dryer before the air compressor, the standard operating procedure provides the following answer:Yes, the refrigerant dryer must be started first, followed by the air compressor.

Why is it necessary to start the refrigerant dryer first?

Start the refrigerant dryer before starting the air compressor, primarily based on the following engineering principles and equipment‑protection requirements:

• Pre-cooling and Steady-State Conditions:After the refrigerant dryer is started, the refrigeration system requires a certain amount of time to reduce the evaporator temperature to the set dew-point range. Starting it in advance ensures that the system reaches its optimal drying condition.
• Preventing water ingress into the pipeline network:If the air compressor is started first, the high‑temperature, high‑humidity compressed air will enter the refrigerant dryer before it has been cooled, preventing moisture from condensing and being removed. This can subsequently contaminate the downstream piping network and gas‑using equipment.
• Avoid thermal shock:The air discharged from the compressor is at a high temperature. If the refrigerant dryer is not started in advance, the hot gas can suddenly surge into the dryer’s internal components, potentially compromising cooling efficiency and reducing equipment lifespan.

Standard start-stop operating procedure

To ensure the stable operation of the gas supply system, it is recommended to follow the standard operating procedures below:

• Power-on sequence:First, turn on the refrigerant dryer and wait for several minutes. Once you’ve confirmed that the dryer is operating normally and the temperature has dropped, start the air compressor, and finally open the valves at the air‑consumption end.
• Shutdown sequence:First, close the gas‑use‑side valve; then stop the air compressor and allow the refrigerant dryer to run for a few minutes to remove any residual gas and moisture from the system; finally, shut down the refrigerant dryer.

Precautions for Daily Operation and Maintenance

In addition to mastering the correct start-up and shutdown sequence, routine maintenance is equally crucial:

• Regular blowdown:Inspect and clean the automatic drain of the refrigerant dryer to ensure that condensate drains smoothly and to prevent secondary evaporation.
• Clean the radiator:Regularly clean the dust from the refrigerant dryer condenser and the air compressor radiator to ensure proper ventilation and heat exchange.
• Environmental Control:Ensure adequate ventilation in the equipment room to prevent excessively high ambient temperatures that could trigger a high-pressure alarm on the refrigerant dryer or cause the air compressor to shut down due to overheating.

Adhering to the proper start-up and shutdown procedures and maintenance guidelines not only enhances the drying quality of compressed air but also effectively extends the service life of the entire air‑supply system.