Can disc purifiers be used on board ships?

Disc purifiers (usually disc centrifuges or disc separators) can be used on board ships, but they need to be specifically designed and selected according to the ship environment, oil type and purification requirements. The following is a key analysis and implementation plan:

1. Applicability to ship applications

(1) Advantages

- Efficient separation: It can quickly remove water and solid particles (such as wear metals and carbon deposits) from fuel and lubricating oil to ensure the reliability of ship engines and hydraulic systems.

- Compact design: Modular models (such as Alfa Laval MOPX and Westfalia Separator) are suitable for ships with limited engine room space.

- Automated operation: Equipped with automatic slag discharge and control systems to reduce crew intervention.

(2) Challenges

- Complex ship operating conditions:

- Rocking and vibration may affect the balance of the centrifuge, requiring a shock-absorbing base and dynamic balancing system.

- High humidity and salt spray environments require equipment corrosion protection (such as stainless steel 316L housing). - Diversity of oil products:

- Need to be compatible with oils of different viscosities (such as heavy fuel oil HFO, diesel MDO, transformer oil).

2. Applicable models and selection points for ships

| Type | Applicable oil products | Typical applications for ships | Key requirements |

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

| Fuel purifier | HFO/MDO | Main and auxiliary engine fuel pretreatment | High temperature resistance (≤98℃), high flow |

| Lubricating oil purifier | System lubricating oil, hydraulic oil | Crankcase oil circulation purification | Fine separation (water <0.5%) |

| Multi-function purifier | Multi-oil switching | Combined fuel and lubricating oil treatment | Quick replacement of density ring and drum |

Selection parameters:

- Processing capacity: ｓｅｌｅｃｔ according to the main engine power (such as a 1000 kW engine requires 500~1000 L/h processing capacity).

- G value: ≥8000 G (to ensure the separation of fine particles).

- Explosion-proof certification: in compliance with ship safety standards such as IMO or EC.

3. Key points for installation and operation on board

(1) Installation requirements

- Location: close to the oil supply unit or circulating oil tank to reduce pipeline pressure ｄｒｏｐ.

- Fixing: rigid base + shock-absorbing pad, allowing tilt ≤15° (to adapt to the swaying of the ship).

- Pipeline: hose buffer is installed at the inlet and outlet to avoid vibration transmission.

(2) Operation adjustment

- Viscosity adaptation:

- Heavy oil needs to be heated to 90~98℃ (to reduce viscosity to 15~25 cSt).

- Light oil or transformer oil is controlled at 40~60℃.

- Slag discharge setting:

- Automatic slag discharge models set intervals according to the degree of pollution (such as HFO slag discharge once every 4 hours).

- Manual slag discharge requires coordination with the engineer's duty schedule.

(3) Maintenance management

- Daily inspection: oil temperature, pressure gauge, vibration and noise.

- Weekly maintenance: clean the disc set and check the seal.

- Anti-corrosion measures: spray anti-salt spray coating on electrical components.

4. Typical ship application scenarios

- Main fuel system: remove moisture and catalytic particles (Cat fines) in HFO to prevent engine wear.

- Lubricating oil management: extend crankcase oil life and reduce oil change frequency.

- Emergency treatment: quickly purify the hydraulic oil contaminated by water inflow.

5. Precautions

- Safety redundancy: Equipped with spare purification units to avoid downtime caused by a single machine failure.

- Environmental compliance: The separated sludge must be stored by the MARPOL Convention (direct discharge into the sea is prohibited).

- Crew training: Focus on training emergency shutdown and manual slag discharge operations.

Disc purifiers (disc centrifuges) can be used reliably on ships, especially for treating highly polluted heavy oil and lubricating oil, but it is necessary to ｓｅｌｅｃｔ marine-certified models and optimize the installation and maintenance process. For special oils such as transformer oil, it is necessary to verify the ineffectiveness of the centrifuge for dissolved gases (such as acetylene) and use vacuum degassing equipment.