Removing these particles is essential for maintaining equipment longevity and grid reliability. Here is how it’s done.
The Filtration Method (Particle Removal)
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TYA Series Vacuum Hydraulic Oil Filtration System[/caption]The most common way to remove solid carbon is through mechanical filtration. Portable Oil Filtration Units (OFUs) are circulated through the breaker tank.
Edge Filters: These use stacks of paper or metal discs to trap fine carbon.
Depth Filters: Use high-density media (like pleated synthetic fibers) to capture particles down to 1 micron or smaller.
The Process: Oil is pumped out from the bottom of the tank, passed through the filter stages, and returned to the top.
Centrifugal Separation
For oil with heavy carbon contamination or high water content, a centrifuge is highly effective.
How it works: The oil is spun at high speeds. Because carbon particles and water are denser than the oil, centrifugal force flings them to the outer walls of the bowl.
Benefit: This is excellent for "bulk" cleaning before moving to fine polishing filters.
Vacuum Degassing and Dehydration
Carbon isn't the only enemy; dissolved gases and moisture often accompany carbonization.
The Method: The oil is heated (usually to about 50°C to 60°C) and sprayed into a vacuum chamber.
The Result: The vacuum pulls out dissolved air and moisture, while the fine-mesh filters in the system catch the carbon. This "polishing" restores the oil’s Dielectric Breakdown Voltage (BDV).
Chemical Reclamation (Adsorption)
If the oil is severely aged (indicated by high acidity or a dark, "burnt" smell), simple filtration might not be enough.
Fuller’s Earth: This is a natural clay used in "reclamation" rigs. As oil passes through the clay, the carbon and acidic products are chemically adsorbed onto the surface of the clay particles.
Result: This restores the oil's color from a dark black/brown back to a clear amber.
Summary Checklist for Maintenance
Before and after the cleaning process, you should perform these standard tests:
| Test Type | Objective | Desired Result |
| Dielectric Strength (BDV) | Measures insulating capability | High voltage threshold (e.g., >30kV) |
| Interfacial Tension (IFT) | Detects polar contaminants/sludge | High tension (indicates "pure" oil) |
| Color/Clarity | Visual check for carbon | Clear and bright (not cloudy or black) |
| Moisture Content | Measures the PPM of water | Low PPM (typically <20 ppm) |