What is the function of the heater of the centrifugal oil filter?

The heater on a centrifugal oil filter is primarily used to improve oil treatment. Its core function is to reduce oil viscosity through heating, thereby enhancing oil-water separation efficiency and impurity removal. Its specific functions are as follows:

1. Reduce oil viscosity and improve separation efficiency

- Cold oil is viscous: At low temperatures, transformer oil (or hydraulic oil) has a high viscosity, making it difficult for water and impurities to be effectively separated by centrifugal force.

- Enhanced fluidity after heating: Heating to 50-70°C (depending on the oil type) significantly reduces viscosity, making it easier for water and solid particles to be removed by centrifugal force.

- Comparison of results:

- Unheated: Longer separation time and higher residual water/impurities.

- Heated: Faster separation and more thorough purification (water can be reduced to below 50ppm).

2. Disrupt oil-water emulsions

- Emulsified water is difficult to separate: Tiny water droplets (<1μm) may become suspended in the oil due to emulsification, making them difficult to separate by simple centrifugation. - Heating to Demulsify: Increasing temperature reduces the interfacial tension between the oil and water, causing small water droplets to coalesce into larger droplets, making them easier to separate by centrifugal force.

3. Assisted Removal of Dissolved Water

- Dissolved Water in Oil: Transformer oil can dissolve a small amount of water at room temperature (approximately 50-100 ppm), which cannot be directly removed by centrifugation.

- Heating to Release Water: Upon heating, the solubility of water decreases, causing some dissolved water to precipitate as free water, which can then be separated by centrifugation.

4. Precautions

- Temperature Control:

- Optimal Range: Generally 50-70°C (temperatures exceeding 80°C may accelerate oil oxidation).

- Avoid Overheating: High temperatures can cause oil degradation (e.g., increased acidity and decreased dielectric strength).

- Enhanced Effect with Vacuum: If the centrifuge is integrated with a vacuum system (e.g., a vacuum centrifuge), heating can further remove volatile water.

5. Suitable Applications for Heaters

- High-Viscosity Oils: Such as lubricating oils in low-temperature environments and used oils (which increase viscosity after oxidation). - Severely emulsified oil, such as transformer oil, that forms a stable emulsified oil after water ingress.

- Precision filtration requirements: extremely low water and impurities are required (such as high-voltage transformer oil to restore insulation performance).

Summary

The role of the heater in the centrifugal oil filter is "physical assistance", which optimizes the oil state by heating and makes centrifugal separation more efficient. However, the temperature must be strictly controlled to avoid oil damage. For deep dehydration (such as transformer oil requirements <10ppm), vacuum dehydration or adsorption filtration is still required.