MDE Unit 9 Q6 – Answer

(a) Flash Point:

  • Problem: Distillate fuel oil has a flash point, the minimum temperature at which it can vaporize and ignite. If the fuel oil temperature reaches or exceeds the flash point in the presence of an ignition source, a fire can occur.
  • How to Avoid:
    • Storage: Store fuel oil in designated, cool, and well-ventilated areas away from heat sources and ignition sources like open flames or sparks.
    • Handling: Implement proper handling procedures to minimize the risk of spills and ensure safe transfer during refueling.
    • Fuel Selection: In some cases, depending on the application and climate, you might consider using a distillate fuel with a higher flash point for increased safety margins.

(b) Wax:

  • Problem: Distillate fuel oil contains paraffin waxes, which can solidify at low temperatures. This can cause problems like:
    • Filter Plugging: Wax crystals can clog fuel filters, restricting fuel flow to the engine and potentially leading to engine stalling or power loss.
    • Poor Flow: Wax formation can thicken the fuel, hindering proper fuel flow within the fuel system.
  • How to Avoid:
    • Fuel Selection: When operating in cold weather conditions, using a distillate fuel with a lower cloud point (temperature at which wax crystals begin to form) is crucial. This ensures the fuel remains liquid at the expected operating temperatures.
    • Fuel Additives: Specific cold flow improver additives can be used to lower the cloud point of the fuel and prevent wax crystal formation at moderate cold temperatures.
    • Proper Storage: Avoid storing fuel oil for extended periods in extremely cold conditions, as this can promote wax separation and solidification.

(c) Microbes:

  • Problem: Microbial growth (bacteria, fungi) can occur in distillate fuel oil, especially if there is water contamination. Microbes can cause several issues:
    • Blocked Filters: Microbial colonies can clog fuel filters, restricting fuel flow.
    • Corrosion: Microbial activity can produce byproducts that contribute to fuel system corrosion.
    • Degraded Fuel Quality: Microbial activity can break down fuel components, reducing its energy content and hindering combustion efficiency.
  • How to Avoid:
    • Minimize Water Ingress: Maintain a water-tight storage system and regularly drain any accumulated water from the fuel tank.
    • Proper Storage Practices: Store fuel in clean, sealed containers and avoid prolonged storage times, especially in warm and humid conditions.
    • Biocide Additives: Consider using biocide fuel additives as a preventative measure to inhibit microbial growth within the fuel.
    • Regular Fuel Testing: Periodically test fuel samples for signs of microbial contamination.