What oil filter is used for industrial waste oil

The purification of industrial waste oil requires the selection of a suitable oil filter according to the type of waste oil (such as lubricating oil, hydraulic oil, cutting fluid, etc.), the degree of contamination (water, particles, oxidation product content) and the regeneration target (base oil recovery or simple reuse). The following is a guide to selecting oil filters for different waste oil situations:

Common pollutants in industrial waste oil and applicable oil filter types

| Pollutants | Recommended oil filter types | Treatment principle | Purification effect |

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

| Solid particles | Plate and frame oil filter/centrifugal oil filter | Mechanical interception or centrifugal separation of metal chips and dust | Particles ≤5μm (NAS 1638 level 8) |

| Free water/emulsified water | Coalescing and dehydrating oil filter/centrifuge | Coalescing filter element demulsification or high-speed centrifugal separation | Water ≤100ppm (demulsification) |

| Dissolved water/gas | Vacuum oil filter | Negative pressure (≤0.1kPa) heating to evaporate water and gas | Water ≤50ppm, gas content ≤0.1% |

| Colloid/oxidation products | White clay adsorption oil filter/electrostatic oil filter | Activated clay adsorbs polar substances, or electrostatic field adsorbs colloidal particles | Acid value ≤ 0.1mgKOH/g |

| Deep oxidation of waste oil | Solvent extraction + distillation equipment | Propane/NMP solvent dissolves active ingredients, distills and separates impurities | Regenerated base oil (close to new oil standards) |

Typical industrial waste oil treatment solutions

1. Waste lubricating oil (engine oil, gear oil)

- Pollutants: metal particles, carbon residue, moisture, acidic substances.

- Recommended equipment:

A[waste oil] --> B[centrifugal separation and slag removal] --> C[vacuum dehydration] --> D[clay adsorption] --> E[precision filtration] --> F[regenerated oil]

- Key parameters:

- Moisture ≤ 200ppm, acid value ≤ 0.3mgKOH/g (GB/T 17145-2017).

2. Waste hydraulic oil (including emulsified water)

- Pollutants: emulsified water, tiny particles.

- Recommended equipment: coalescing vacuum oil filter (such as Parker ICON series).

- Treatment effect:

- Water content ≤50ppm after demulsification, cleanliness ISO 4406 15/12/9.

3. Waste cutting fluid (including metal powder)

- Pollutants: metal debris, emulsion.

- Recommended equipment: centrifuge + magnetic filter (such as Alfa Laval MOPX).

- Advantages: No filter element is required, and the efficiency of treating high-solid content waste liquid is high.

4. Waste transformer oil (insulation needs to be restored)

- Pollutants: moisture, gas, fiber.

- Recommended equipment: two-stage vacuum oil filter (such as HYDAC TF series).

- Standard: breakdown voltage ≥60kV (IEC 60156).

Deep regeneration process (refining base oil from waste oil)

For heavily polluted waste oil, a combination of chemical treatments is required:

1. Pretreatment: 

-centrifugal impurity removal → distillation and dehydration.

2. Main treatment:

- Solvent extraction (propane or NMP) to remove asphalt and heavy metals.

- Hydrofining (high temperature and high pressure catalysis) to remove sulfur and nitrogen.

3. Equipment:

- Distillation tower (such as GEA molecular distillation equipment).

- Hydrogenation reactor (such as Pall hydrogenation system).

Selection considerations

1. Oil compatibility:

- Mineral oil and synthetic ester oil require different filter materials (esters may dissolve ordinary seals).

2. Economic efficiency:

- Mild pollution: physical purification (cost ≈ 20% of new oil).

- Severe pollution: chemical regeneration (cost ≈ 60% of new oil).

3. Environmental regulations:

- Waste oil treatment must comply with GB 17145-2017, hazardous waste code HW08.

Operational recommendations

- Small-scale treatment: Use a mobile oil filter vehicle (such as Bosch Rexroth HED).

- Continuous production: Install an online oil filter system (such as Parker ICON).

- Waste oil recycling: Entrust a professional recycling company (hazardous waste business license required).

By properly selecting an oil filter, the recovery rate of industrial waste oil can reach 80%~95%, greatly reducing the cost and environmental risks of waste oil disposal. For high-value oil products (such as aviation hydraulic oil), it is recommended to give priority to high-precision equipment such as Pall or CJC.