Maintenance of Desiccant Air Dryers

Abnormal operation or failures of desiccant air dryers will lead to poor compressed air quality, which in turn poses risks to equipment and products. Therefore, 

enterprises shall conduct regular inspection and maintenance to ensure stable equipment operation. Contact the manufacturer promptly if any unresolved faults occur.

First, it is necessary to understand the working process of desiccant air dryers. Observe the operating status and check whether each controller triggers corresponding actions of solenoid valves and pneumatic valves. 

The adsorption chamber of a desiccant air dryer maintains full pressure during operation, and dry air flows into the regenerating chamber to complete the regeneration process.

Adsorption Stage of Modular Core Dryer
Wet compressed air enters the inlet buffer chamber and flows upward evenly through each modular core adsorption chamber. The molecular sieve absorbs moisture from compressed air via capillary action to realize air drying.
Regeneration Stage of Modular Core Dryer (Micro-heat Regeneration)

For micro-heat regeneration, dry regeneration air flows through the regeneration airflow regulating valve into the outlet manifold of the regeneration group. 

After high-temperature dry gas expands and decompresses to atmospheric pressure inside the modular core adsorption chamber of the regeneration group, 

it purges the molecular sieve from top to bottom. This accelerates the separation of moisture from the adsorbent. The separated moisture is desorbed into dry air and discharged together with regeneration gas through the muffler.

A comprehensive understanding of the working process of desiccant air dryers facilitates troubleshooting of various malfunctions.
Abnormal Pressure Readings
Damaged pressure sensor
Solution: Install a new pressure sensor.
Leakage or blockage of the solenoid valve assembly
Solution: Clean the solenoid valve seat and muffler; replace components if damaged.
Blocked or ruptured air pipe
Solution: Check air pipeline ventilation; replace pipes immediately if abnormal.
Loosened or damaged valve seat pressure plate
Solution: Inspect the pressure plate and replace it when necessary.
Damaged air cylinder
Solution: Check the movement of the air cylinder and replace it if needed.
Loss of elasticity of check valve spring
Solution: Replace the spring.
Clogged solenoid valve muffler
Solution: Dismantle and clean the muffler; replace it immediately if severely clogged or damaged.
Excessive regeneration airflow
Solution: Reduce the opening of the regeneration airflow regulating valve (Note: Ensure consistent opening of the valves). Inspect check valves and inlet valves, and replace them as required if faults exist.
Abnormal Operation of Controller Program
Damaged controller
Solution: Test the controller and replace it immediately if defective.
Trace Moisture Contained in Treated Air
Excessive processing flow or excessive oil content of the matched air compressor
Solution: Check the operating condition of the air compressor.
Heavy rust inside the main air supply pipeline blocking muffler valves
Solution: Purge all rust inside pipelines and air receivers, and clean contaminants at the bottom of the muffler.
Excessively High Dew Point
Inlet air quality fails to meet specified standards
Solution: Adjust inlet air pressure and temperature.
Insufficient regeneration airflow
Solution: Adjust the regeneration air valve (ensure consistent opening of both groups of valves), or contact after-sales service personnel.
Pipeline cross-communication
Solution: Verify that the bypass valve is fully closed and confirm whether dried air is connected with gas from other pipelines.
Emergency Shutdown
Automatic power cut
Cause: Circuit overload
Solution: Inspect the circuit and replace short-circuited components.
Low-pressure shutdown
Cause: Too low inlet air pressure
Solution: Adjust inlet air pressure to the specified standard.
High-temperature shutdown
Cause: Abnormal wiring of temperature control module, malfunction of solid-state relay or temperature sensing probe
Solution: Inspect wiring of the temperature control module, solid-state relay and temperature probe; replace abnormal or damaged components in a timely manner.

Regular maintenance is required for desiccant air dryers to guarantee stable operation and extend service life. Hence, enterprises must attach importance to the maintenance of desiccant air dryers. 

Stable operation of the equipment ensures reliable production.