Hướng Dẫn Xử Lý Sự Cố Máy Làm Mát Chân Không: Quy Trình Kiểm Tra Thực Tế
Hướng dẫn kiểm tra thực tế có hệ thống cho năm vấn đề phổ biến nhất của máy làm mát chân không — insufficient vacuum, slow cooling, high water loss, refrigeration anomalies, and control system failures.
Năm Vấn Đề Khách Hàng Thường Gặp
Over 80% of field issues can be resolved through systematic inspection.
① Độ Chân Không Không Đủ (Below 660Pa)
| # | Check Item | Action | Time |
|---|---|---|---|
| 1 | Vacuum pump | Normal sound, no abnormal vibration | 2min |
| 2 | Pump oil | Level 1/2~2/3, no emulsification (milky) | 3min |
| 3 | Door seal | Wear, deformation, micro-cracks on chamber welds | 5min |
| 4 | Piping | Butterfly valve fully open, no loose connections | 3min |
| 5 | Water catcher | Ice blockage, defrost water path clear | 5min |
| 6 | Vacuum gauge | Mechanical vs PLC display match | 3min |
Solutions:
- Oil emulsified → Replace with 100# oil, check catcher evaporator temp (5~10°C)
- Door seal worn → Replace seal, adjust clamping mechanism
- Catcher iced → Check defrost cycle, verify refrigerant charge
② Tốc Độ Làm Mát Chậm
Over 70% caused by loading/stacking issues, not equipment failure.
- Batch load exceeds 90% design capacity
- Product layer spacing < 5cm creates air circulation dead zones
- Vacuum fails to reach 4kPa within first 5 minutes
③ Mất Nước Quá Mức
Compare actual to standard pressure-time curve. Deviation >15% requires vacuum setpoint adjustment or load reduction.
④ Hệ Thống Lạnh Bất Thường
Use infrared thermometer: condenser inlet-outlet ΔT >8°C (normal), compressor return line 5~15°C (normal) for rapid diagnosis.
⑤ Lỗi Hệ Thống Điều Khiển
Power cycle (disconnect 2 min) resolves 80% of PLC transient faults.
Nghiên Cứu Trường Hợp: Hợp Tác Xã Thượng Hải CVF-1500A-4P
Problem: After 2 months, vacuum reached only 1200Pa (target 660Pa). Batch time extended from 20 to 45 minutes.
Root Cause: High-moisture leafy greens overloaded the water catcher. Water vapor bypassed into the vacuum pump, causing oil emulsification.
Fix: Replace oil → Adjust catcher evaporator temp to 8°C → Reduce load from 90% to 70% → Install oil-water separator.
Result: Vacuum restored to 520Pa, cooling time 25 minutes. Stable operation ongoing.
Case data from actual Công ty Yuanxian Machinery field service records. CVF series covers 50kg~6000kg batch capacity.