The performance of a marine fuel oil purifier depends heavily on maintaining the correct operating parameters. Even if the purifier is mechanically perfect, wrong temperature, pressure, throughput, or bowl speed can drastically reduce separation efficiency.
Why Operating Parameters Are Important
A purifier works on centrifugal force and density difference. If the operating conditions are not within limits, water and sludge cannot separate properly. This may result in oil contamination, oil loss, poor combustion, and machinery damage. Maintaining correct parameters ensures stable and efficient purification onboard ships.
1. Fuel Oil Temperature
Recommended Range
- 98°C – 104°C (for heavy fuel oil)
Why Temperature Matters
Heating reduces viscosity and allows easier separation. Warm fuel flows smoothly between disc stack layers, improving separation speed and efficiency.
If Temperature is Too Low
- High viscosity
- Poor separation
- Water carryover
- Sludge accumulation
If Temperature is Too High
- Fuel vaporization
- Loss of sealing water
- Reduced efficiency
Tip: Always start oil feed only after reaching correct temperature.
2. Operating Water Pressure
Typical Range
- 2 – 3 bar (as per maker’s manual)
Purpose
Operating water provides hydraulic force to close and open the sliding bowl bottom during desludging.
If Pressure is Too Low
- Bowl may not close properly
- Oil leakage
- Poor separation
If Pressure is Too High
- Seal damage
- Mechanical stress on parts
Tip: Always ensure clean, filtered water supply.
3. Throughput (Flow Rate)
Typical Range
- As recommended by manufacturer (example: 1500–3000 L/hr depending on model)
Why Throughput Matters
Throughput controls how long the oil stays inside the bowl. Proper residence time is necessary for complete separation.
If Flow is Too High
- Insufficient separation time
- Water in clean oil
- Sludge carryover
If Flow is Too Low
- Reduced purifier capacity
- Unnecessary energy consumption
Tip: Maintain maker’s rated capacity for best results.
4. Bowl Speed (RPM)
Typical Speed
- 7,000 – 9,000 RPM (depending on purifier type)
Why RPM is Critical
Higher rotational speed produces strong centrifugal force which separates oil, water, and solids effectively.
Reference Table
| Parameter | Normal Value | Effect if Incorrect |
|---|---|---|
| Temperature | 98–104°C | Poor separation or vapor issues |
| Operating Water Pressure | 2–3 bar | Bowl not closing/opening properly |
| Throughput | Maker’s rated capacity | Reduced efficiency |
| RPM | 7000–9000 | Weak centrifugal force |
Daily Watchkeeping Checklist
- Check fuel temperature
- Verify operating water pressure
- Confirm rated bowl speed
- Adjust throughput
- Observe discharge clarity
These quick checks ensure the purifier runs safely throughout the watch eficiently.