1. The nitrogen purity is not qualified for long-term alarm;
2. The carbon molecular sieve sinks and the carbon level automatically alarms;
3. The air storage tank drain valve discharges oil and a large amount of water;
4. The adsorption tower muffler sprays dust;
5. The buffer tank drain valve discharges the carbon molecular sieve particles;
6. The freeze dryer and adsorption dryer are faulty.