What is the principle of oil purification?

The principle of oil purification revolves around separating contaminants from oil to restore its quality and extend its usable life. This is done primarily by exploiting differences in the physical properties of oil and contaminants, such as density, size, and solubility. The key principles include:

1. Density Difference (Centrifugal Separation): One of the most common methods, especially in centrifugal purifiers, uses the difference in density between oil, water, and solid particles. When oil is rapidly spun in a centrifugal chamber, denser contaminants like water and solid particles move outward, while the less dense, purified oil stays in the center and is collected.

2. Vacuum Distillation (Dehydration and Degassing): Vacuum dehydration uses reduced pressure to lower the boiling point of water and dissolved gases within the oil. By heating the oil slightly and applying a vacuum, water, and gases vaporize at a lower temperature, which can then be vented off, leaving the oil cleaner and moisture-free. This principle is vital in applications where even trace amounts of moisture or gas can impact performance, like transformer oils.

3. Filtration (Physical Barrier): Fine filters trap and remove solid particles using a physical barrier. Their pore size can vary, allowing precise control over the types of contaminants removed. In oil purification, filters are often used as the final purification step to capture any residual fine particles.

4. Adsorption (Chemical Attraction): Some purifiers use adsorbent materials (e.g., activated clay or carbon) to capture contaminants chemically. These materials attract and hold pollutants like acids, oxidation products, and other dissolved impurities. Adsorption is especially useful in refining oils that may have degraded chemically over time.

By combining these principles, oil purifiers effectively separate contaminants, maintain oil purity and enhance the longevity and efficiency of the equipment that relies on the purified oil.