Shutdown sequence of air compressor and cold dryer

The shutdown sequence of the air compressor and the cold dryer shall be: close the air compressor first, and then close the cold dryer after the system pressure is released. Specific steps and reasons are as follows:

1. shutdown sequence and steps

1. close air compressor
   • operation: Press the air compressor stop button, and the equipment will stop gradually.
   • Purpose: Stop compressed air production to avoid continuous pressurization of the system.
2. Wait for pressure release
   • operation: Observe the pressure gauge and wait until the system pressure drops to a safe range (usually ≤ 0.1MPa).
   • Purpose: Prevent high-pressure air from impacting the cold dryer and other pipelines to protect the safety of the equipment.
3. Close the cold dryer
   • operation: Press the stop button of the cold dryer, and the equipment will be powered off and shut down.
   • Purpose: Stop the air drying process to avoid the cold dryer running under no load or low pressure.

Why do 2. need to stop in this order?

1. Protect the cold dryer
   • if the air compressor is turned off first, the internal pressure of the air compressor may increase sharply, causing pipeline rupture or seal damage.
   • After the cold dryer is closed, if there is still high-pressure air in the system, it may flow backwards through the cold dryer and damage its internal structure.
2. Avoid system water accumulation
   • after the air compressor stops, the system pressure gradually decreases, and the cold dryer can continue to discharge residual moisture to prevent pipeline corrosion.
3. Extend equipment life
   • sequential shutdown reduces the impact of frequent start-up and shutdown of equipment and reduces the risk of mechanical wear and electrical failure.

3. special circumstances

1. emergency stop
   • in case of emergency (such as abnormal equipment and leakage), the air compressor and cold dryer shall be closed at the same time, and the system pressure shall be emptied immediately.
2. Long-term shutdown
   • before closing, drain the water in the air storage tank, pipeline and cold dryer to prevent frost cracking or corrosion.

4. Summary

following the shutdown sequence of "first air compressor, then cold dryer" can ensure system safety, extend equipment life, and avoid equipment damage or safety hazards caused by improper operation. During actual shutdown, the operation details shall be adjusted in combination with the equipment specification and on-site working conditions.