Working principle of coalescence separation oil purifier

Coalescence separation oil purifier is a high-efficiency oil purification equipment, mainly used to remove water, gas and mechanical impurities (such as metal particles, dust) in oil, especially suitable for the purification of industrial oils such as insulating oil, lubricating oil, hydraulic oil, etc. Its core working principle is divided into two stages: coalescence and separation. The following is a detailed analysis:

Workflow

1. Coalescence stage (Coalescence)

- Goal: Aggregate tiny suspended water droplets in the oil into large water droplets.

- Process:

1. Oil passes through the coalescence filter element:

- The filter element is made of hydrophilic materials (such as glass fiber, special polymer) and has a microporous structure on the surface.

- After the tiny water droplets (1~10 microns) hit the filter element fiber, they are adsorbed on the fiber surface due to surface tension.

2. Water droplet merging (coalescence):

- The adsorbed water droplets gradually gather to form larger water droplets (50~100 microns), and finally detach from the filter element due to gravity.

Separation stage (Separation)

- Goal: to completely separate the large water droplets after coalescence from the oil.

- Process:

1. The oil-water mixture flows into the separation chamber:

- A hydrophobic membrane or centrifugal device is installed in the separation chamber to separate the oil and water by using the density difference between oil and water (oil is light, water is heavy).

2. Gravity sedimentation or centrifugal force:

- Large water droplets settle to the bottom drain port, and dry oil flows out from the upper outlet.

3. Gas removal (optional):

- Some equipment integrates a vacuum system to extract the gas dissolved in the oil (such as oxygen and nitrogen).

Key components and functions

| Components | Function |

|-------------------|-------------------------------------------------------------------------|

| Coalescing filter element | Capture tiny water droplets and promote their merging. The material needs to be oil-resistant and high-temperature resistant (such as polyester fiber). |

| Separation filter element/bin | Hydrophobic materials (such as polytetrafluoroethylene) prevent water droplets from floating up to ensure the purity of the oil. |

| Vacuum system | (Optional) Reduce the gas pressure of the oil to accelerate the evaporation of water and gas removal. |

| Heating system | (Optional) Heat the oil to reduce viscosity and improve the coalescence efficiency (usually control the temperature at 40~60℃). |

| Control system | Automatically monitor the cleanliness of the oil (such as water content ppm) and pressure difference, and prompt the replacement of the filter element. |

Technical features

1. Efficient dehydration: 

It can process oil with a water content of ≤15%, and the water content after purification is ≤50ppm (ISO 4406 standard).

2. Multi-stage filtration:

- First, remove large particles (≥10 microns) through the pre-filter to protect the coalescence filter element.

- The post-fine filter (such as 3 microns) ensures that there is no solid residue.

3. Strong adaptability:

- Can handle mineral oil and synthetic oil (such as silicone oil and ester oil).

- Corrosion-resistant design (suitable for acidic oil).

Application scenarios

- Power industry: Transformer insulation oil purification (remove moisture to prevent breakdown).

- Ship/Aviation: Hydraulic oil, lubricating oil regeneration (extend oil change cycle).

- Manufacturing industry: Cutting fluid, rolling oil recovery (reduce waste oil treatment costs).

Differences from ordinary oil filters

| Comparison items | Coalescing separation oil purifier | Ordinary vacuum oil filter |

|------------------|--------------------------------------|--------------------------------|

| Water removal principle | Coalescing + gravity separation | Vacuum evaporation |

| Water removal efficiency | Higher (suitable for trace moisture) | Depends on oil temperature, dissolved water may remain |

| Energy consumption | Lower (no high temperature vacuum) | Higher (requires heating and vacuum pump) |

| Maintenance cost | Coalescing filter element needs to be replaced regularly | Vacuum pump maintenance is complicated |

If specific model selection is required (such as flow rate, oil type matching), oil parameters can be provided for further analysis!