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Time：2025-07-24 15:32:56 Reading volume：
Removing moisture from insulating oil is a key step to ensure the safe operation of electrical equipment (such as transformers, cables, etc.). Moisture can reduce the insulation performance of oil, accelerate oil aging, and even cause equipment failure. The following are common removal techniques and precautions:
1. Vacuum dehydration method
- Principle: In a vacuum environment, the boiling point of water decreases, and the water is evaporated by heating (usually 60-70℃) and vacuuming (vacuum degree ≤50 Pa).
- Advantages: High efficiency, suitable for large-scale oil treatment, and can be degassed at the same time.
- Equipment: Vacuum oil filter (including heater, vacuum pump, condenser, etc.).
2. Centrifugal separation method
- Principle: Use centrifugal force to separate free water in oil (density difference).
- Applicable: Only effective for free water; and other methods are required to treat dissolved water.
3. Adsorption filtration method
- Materials: Use water-absorbing media (such as silica gel, molecular sieve, activated alumina) to filter the oil.
- Note: The adsorbent needs to be replaced regularly to avoid secondary contamination.
1. Desiccant addition
- Add a small amount (ppm level) of water absorbent (such as calcium borate), but the amount must be strictly controlled to avoid affecting the oil quality.
2. Coagulation dehydration
- Use the coagulation material to merge the tiny water droplets into large droplets, and then separate them by gravity or centrifugation.
1. Temperature control: The heating temperature should not be too high (generally ≤80℃) to prevent oil oxidation.
2. Vacuum degree: The higher the vacuum degree, the better the dehydration efficiency, but oil splashing should be avoided.
3. Oil quality monitoring: Detect the moisture content after treatment (GB/T 7600 or ASTM D1533 standard), usually requiring ≤10-15 ppm (ultra-high pressure equipment requires lower).
4. System sealing: The treated oil should be stored in a sealed manner to prevent air humidity from re-invading.
5. Environmental protection requirements: Waste oil and adsorbents must be handled according to hazardous waste specifications.
If there is no professional equipment on site, the following methods can be used temporarily:
- Standing stratification: Let the oil stand for more than 24 hours, and the free water at the bottom will be released through the drain valve.
- Heating sedimentation: Gentle heating (≤50℃) accelerates water sedimentation, but the effect is limited.
- Regularly test the moisture content in the oil (such as Karl Fischer method).
- For severely damp equipment, it is necessary to combine the drying treatment of solid insulating materials (such as cardboard).
The above methods can effectively reduce the moisture content of insulating oil, restoring its insulation strength and cooling performance. For large power equipment, it is recommended to entrust a professional company to use an integrated oil filter truck for treatment.
