.2.3 Pre-treatment of marine fuels Learning Objectives The main objectives of this section are to make all engineers familiar with Pre-treatment of marine fuels Design criteria, or problems related to settling e and service tanks Draining of settling tanks .B Preheating Separation, purifier and clarifier. o Sludge and sludge handling
2.3 Pre-treatment of marine fuels • Learning Objectives The main objectives of this section are to make all engineers familiar with: ❖Pre-treatment of marine fuels. ❖Design criteria, or problems related to settling and service tanks. ❖Draining of settling tanks. ❖Preheating. Separation, purifier and clarifier. ❖ Sludge and sludge handling
2.3 Pre-treatment of marine fuels Design criteria, or problems related to settling and service tanks Draining and cleaning: It is most important to examine and clean settling and service tanks regularly for sludge. If satisfactory fuel is transferred into a tank containing sludge, waxy sludge may be thrown down from it as a result of a seeding action by the micro-crystals already present
2.3 Pre-treatment of marine fuels • Design criteria, or problems related to settling and service tanks. – Draining and cleaning: It is most important to examine and clean settling and service tanks regularly for sludge. If satisfactory fuel is transferred into a tank containing sludge, waxy sludge may be thrown down from it as a result of a seeding action by the micro-crystals already present
2.3 Pre-treatment of marine fuels Draining and ventilation: Tanks containing heated fuel oil should be vented to a safe position outside the engine room and as in the case of all fuel oil tanks, the end of the vent pipes should be fitted with wire gauze diaphragms Openings in the drainage systems of tanks containing heated fuel oil, should be located in spaces where no accumulation of fuel vapors at temperatures close to the flash point can occur. There should be no source of ignition in the vicinity of these vent pipes or near the openings in the drainage systems
2.3 Pre-treatment of marine fuels – Draining and ventilation: Tanks containing heated fuel oil should be vented to a safe position outside the engine room and as in the case of all fuel oil tanks, the end of the vent pipes should be fitted with wire gauze diaphragms. Openings in the drainage systems of tanks containing heated fuel oil, should be located in spaces where no accumulation of fuel vapors at temperatures close to the flash point can occur. There should be no source of ignition in the vicinity of these vent pipes or near the openings in the drainage systems
2.3 Pre-treatment of marine fuels Settling tanks: Normally, two settling tanks should be fitted, each having sufficient capacity of 24 hours normal service consumption. The 24 hours capacity is provided to enable some natural gravitational separation of free water to take place, and to enable he temperature of the fuel to stabilize prior to pre- combustion treatment. Both settling and service tanks should have sloping bottoms, to enable easy draining from the tanks. In addition it is preferable with perforated plates fitted parallel to the tank bottoms to keep possible sediment in place
2.3 Pre-treatment of marine fuels – Settling tanks: Normally, two settling tanks should be fitted, each having sufficient capacity of 24 hours normal service consumption. The 24 hours capacity is provided to enable some natural gravitational separation of free water to take place, and to enable the temperature of the fuel to stabilize prior to precombustion treatment. Both settling and service tanks should have sloping bottoms, to enable easy draining from the tanks. In addition it is preferable with perforated plates fitted parallel to the tank bottoms to keep possible sediment in place
2.3 Pre-treatment of marine fuels Remember: It is of great importance to establish routines for draining the settling tanks to prevent build up of water and sludge, which may cause problems due to the separation process. Service tanke: design features of the service tanks should be similar to those of settling tanks. Overflow from the service tanks should be led to the bottom of the settling tanks, or preferable 300mm above the bottom and away from the outlets. High and low suction pipes in service tanks should be located above water and sludge drains
2.3 Pre-treatment of marine fuels – Remember: It is of great importance to establish routines for draining the settling tanks to prevent build up of water and sludge, which may cause problems due to the separation process. – Service tank: Design features of the service tanks should be similar to those of settling tanks. Overflow from the service tanks should be led to the bottom of the settling tanks, or preferable, 300mm above the bottom and away from the outlets. High and low suction pipes in service tanks should be located above water and sludge drains