คู่มือแก้ไขปัญหาเครื่องทำความเย็นสุญญากาศ: แนวทางการตรวจสอบภาคสนามพร้อมกรณีศึกษาจริง

ปัญหาทั่วไปห้าประการของลูกค้า

Over 80% of field issues can be resolved through systematic inspection.

① สุญญากาศไม่เพียงพอ (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 การทำความเย็นช้า

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 การสูญเสียน้ำมากเกินไป

Compare actual to standard pressure-time curve. Deviation >15% requires vacuum setpoint adjustment or load reduction.

④ ความผิดปกติของระบบทำความเย็น

Use infrared thermometer: condenser inlet-outlet ΔT >8°C (normal), compressor return line 5~15°C (normal) for rapid diagnosis.

⑤ ความล้มเหลวของระบบควบคุม

Power cycle (disconnect 2 min) resolves 80% of PLC transient faults.

กรณีศึกษา: สหกรณ์เซี่ยงไฮ้ 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.

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Case data from actual บริษัท Yuanxian Machinery field service records. CVF series covers 50kg~6000kg batch capacity.