There is still water in the screw compressor after passing through the refrigerant dryer.

I. The inlet air conditions exceed the equipment’s processing capacity.

The operating principle of a refrigerated air dryer is to cool the compressed air, causing the water vapor it contains to condense into liquid water that is then discharged. If the temperature of the compressed air entering the dryer is too high, or if the actual air flow rate exceeds the equipment’s rated capacity, the moisture in the air cannot be fully condensed. Furthermore, if the dryer is installed in an environment with poor ventilation or excessively high ambient temperatures, the condenser’s heat dissipation will be impaired, reducing cooling efficiency and resulting in outlet air with moisture levels exceeding the specified limits.

II. Malfunction of the Refrigeration System in the Air Dryer Itself

The core of a refrigerant dryer lies in its refrigeration system. If there is a refrigerant leak within the system or if the refrigeration compressor’s efficiency declines, the evaporator temperature will fail to reach its design range, causing the pressure dew point to rise. Meanwhile, if ice formation inside the evaporator leads to blockage, or if the automatic drain malfunctions and condensate cannot be discharged promptly, the condensed water may be carried back into the downstream piping by the airflow, resulting in moisture at the outlet.

III. Design Deficiencies in Front-End Cooling and Rear-End Piping

If the aftercooler at the compressor’s downstream end experiences reduced heat‑transfer efficiency, the air entering the refrigerant dryer can exceed its design temperature, significantly increasing the dryer’s load. In the piping downstream of the refrigerant dryer, inadequate pipe slope, low‑lying water‑collection points, or the absence of an effective automatic drain can cause condensate to accumulate within the lines. This accumulated condensate may then be entrained by the airflow, resulting in liquid water being discharged along with the compressed air.

IV. System Troubleshooting and Optimization Recommendations

To address the issue of water carryover in compressed air, it is recommended to conduct a systematic inspection and optimization from the following aspects:

• Check operating parameters:Observe whether the evaporator pressure and condenser pressure of the refrigerant dryer are within their normal ranges, and confirm that the refrigeration system is operating properly.
• Improve the thermal environment:Ensure there is sufficient clearance around the refrigerant dryer for heat dissipation, clean dust from the condenser surface, and maintain adequate ventilation.
• Maintenance of drainage systems:Regularly inspect and clean the automatic drain valves on the refrigerant dryer and the downstream piping to ensure smooth drainage and prevent blockages.
• Optimize pipeline design:Inspect the slope of the downstream piping to ensure condensate flows smoothly to the drain point; if necessary, install an air‑water separator at the terminal end.
• Assess drying requirements:If the production process demands an extremely high level of compressed air dryness and the pressure dew point of a refrigerated dryer cannot meet this requirement, consider installing an adsorption dryer in series to further reduce the dew point.