Vacuum Dehydration Oil Purifier: Working Principle

A vacuum dehydration oil purifier is one of the most advanced oil purification systems. Unlike traditional filters or centrifugal purifiers, it removes not only solid particles but also dissolved water, gases, and light hydrocarbons—achieving deep purification that conventional methods cannot.

Vacuum Dehydration Oil Purifier Working Principle

Its operation is based on a simple physical law:

The boiling point of liquids decreases under vacuum.

By creating a high-vacuum environment and heating the oil moderately, the system forces water and gas molecules to vaporize and separate from the oil. The process includes three stages:

Stage 1: Pretreatment — Heating and Coarse Filtration

Coarse Filtration: The inlet pump draws oil through a pre-filter that removes large impurities (over 100 microns) such as dust, fibers, and metal particles.

→ Protects pumps and heaters from wear or blockage.

Heating: The oil is gently heated (typically 45–65°C) to reduce viscosity and give energy to trapped water and gas molecules, preparing them for rapid evaporation under vacuum.

Stage 2: Core Treatment — Vacuum Dehydration and Degassing

Vacuum Environment: The separator maintains a high vacuum (around -0.095 MPa), reducing the boiling point of water to about 40°C.

Atomization: Heated oil is sprayed into fine droplets or a thin film, increasing surface area for faster evaporation.

Separation:

Water vaporizes and exits as steam.

Dissolved gases (oxygen, nitrogen) and light hydrocarbons are released.

The vapor mixture passes through a condenser, where water is cooled and collected.

Non-condensable gases are vented safely.

The dehydrated, degassed oil collects at the bottom of the separator.

Stage 3: Post-Treatment — Fine Filtration and Discharge

Fine Filtration: The purified oil passes through a 1–10 micron filter to remove remaining fine particles.

Discharge: Clean oil—now low in water, gas, and solids—is pumped back to equipment such as transformers, turbines, or hydraulic systems.

Process Flow Overview

Contaminated Oil → Coarse Filter → Heater → Vacuum Separator → Condenser → Fine Filter → Clean, Dry Oil

Key Advantages

Deep Dehydration: Reduces water to below 100 ppm, or even <10 ppm.

Efficient Degassing: Eliminates dissolved gases to prevent oxidation and cavitation.

Demulsification: Breaks oil-water emulsions, restoring clarity.

Comprehensive Purification: Achieves dehydration + degassing + particle removal in one process.

Applications

Ideal for industries requiring high oil purity, including:

Power: Transformer insulating oil purification

Aerospace: Precision hydraulic systems

Manufacturing: Turbine and lubrication oil maintenance