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6 Oil Fuel and supply main engine

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6 Oil Fuel and supply main engine Powered By Docstoc
					Marine Oily Handling Devices
  and Pollution Prevention

       Chapter 1   Lesson 6
       Oil Fuel Transfer
         1.6 Oil fuel transfer

Oil fuel transfer
arrangements
provide for
receiving stations
at an upper deck
level, port and
starboard,
furnished with
valves, elbows,
pressure gauges,
filters and relief
valves.
        1.6 Oil fuel transfer
 From these receiving
  stations, the oil flows to
  double-bottom, peak or
  deep bunker tanks and
  can be transferred
  from forward to aft and
  from port to starboard
  (and vice versa) and
  from settling to service
  tanks via filters,
  separators and
  clarifiers, thence to
  boilers or engines.
                                                                                                                S      SELF CLOSING COCK

                                                                                                                       DECK CONTROLLED
                                                                                                                            VALVE
      SETTLING          SERVICE                   SETTLING        SERVICE   SERVICE                   BOILER
        TANK             TANK                       TANK           TANK      TANK                      TANK
        D.OIL            D.OIL                      H.OIL          H.OIL     H.OIL                               A       ALARM


       S    T              T   S                   S     T        S   T     S      T                    T   S   P.       PURIFIER

                                                                                                                C.        CLARIFIER

                                                                                                                       S.D.N.R. VALVE
                                                                                                         TO
                                                                                                       BOILER
A                                                                                                                      SCREW LIFT VALVE

                HEATER            HEATER    A            HEATER                 HEATER                DUPLEX    D.O.      DIESEL OIL
                                                                                                      FILTER
     C.O.
    CHEST
                                                                                                                H.O.      HEAVY OIL
            D.O                D.O
                                                    H.O               H.O   H.O             H.O
            H.O                H.O                                                                                      THERMOMETER
                                                    .P.                C    ..P.             C.                 T.
             P.                 P.                                                                                         POCKET

            TO OVERFLOW TANK


    TRANSFER PUMPS

                  D.O
                                           H.O

                                                                                            DUPLEX
                           DUPLEX                                                           FILTERS
                          STRAINERS                                                                    HEATER
                                                                                   TO
                                                                                GENERATOR

                          DRAIN                  OILY                 OVERBOARD             TO MAINENGINE
                          TANK                   BILGE
      1.6 Oil fuel transfer

 The flash point (closed test) should be above 65℃;
  DO should not be heated to more than 51℃ for
  settling or purification; if necessary, this may be
  increased to a figure 20℃ beneath its known flash
  point.
 Settling tanks must have thermometers and the
  sounding arrangements must be proof against
  accidental egress of oil.
           1.6 Oil fuel transfer

 Drain cocks must be self-        S   SELF CLOSING COCK


                                       DECK CONTROLLED
  closing and the outlet valves             VALVE


  should be capable of being
  closed from safe positions           SERVICE
                                        TANK
                                        H.OIL
  outside the engine room.
                                       S   T
 In passenger ships, this
                                   Drain To
  applies also to suction and      valve engine
  leveling valves on deep tanks.
         1.6 Oil fuel transfer
 Overflow pipes and relief valves not in closed
  circuit must discharge to an overflow tank having
  an alarm device, the discharge being visible.
 Tank air pipes must have 25% more area than their
  filling pipes and should have their outlets situated
  clear of fire risks.
 They should also be fitted with detachable wire
  gauze diaphragms.
 Provision should be made for stopping oil fuel
  pumps from outside the machinery spaces.
        1.6 Oil fuel transfer
 From the filling stations, pipes descend to the
  oil fuel mains.
 These will probably be two pipes, one for
  heavy oil and one for diesel fuel.
 They extend forward and aft in the engine
  and boiler rooms, possibly extending along
  the shaft tunnel, and in some ships, a forward
  pipe tunnel.
        1.6 Oil fuel transfer
 These connect to the fuel transfer pumps and to
  distribution valve chests, from which pipes run to
  the fuel tanks.
 Water ballast is also sometimes carried in these
  tanks and the chests are arranged so that they
  cannot be connected to oil and ballast mains at the
  same time (old tanker).
 Midship tanks have center and wing suctions; the
  forward and aft peak, and keep tanks have center
  suction only.
         1.6 Oil fuel transfer
 Transfer pumps draw from the oil mains, from
  overflow and drain tanks and from the oily bilges -
  parts of the engine and boiler room bilges separated
  from the remainder by coamings - to which oil
  spillage is led.
 The pumps discharge to settling tanks, the oily
  water separator and the oil mains.
      1.6 Oil fuel transfer
 In passenger ships, it must be possible to transfer
  oil from any tank to any other tank without use
  of the ballast main, so that two oil mains are
  required.
 In cargo ships, the ballast pump may act as
  standby transfer pump, in which case they must
  be interconnected; alternatively, a diesel oil
  transfer pump may be the standby.
 Detail and arrangement will vary with the size,
  type and trade of the ship.
          1.6 Oil fuel transfer

 In steamers, the fuel is heated in the settling tanks
  by steam coils, to assist water separation, and is
  then taken to the burners through heaters and filters
  by the oil fuel pressure pumps.
 In motorships, after settling in a similar manner the
  heavy fuel passes through heaters to two separators
  in series, the first removing the water and most of
  the solids in suspension; the second, called a
  clarifier, removes the finer solids remaining.
      1.6 Oil fuel transfer
 The separators, usually having their own
  pumps, deliver the clean oil to one of two
  service tanks in turn, from which the oil
  passes to the engine service pumps and so
  to the injection pumps, through further         HEATER

  heaters.
 Diesel fuel is treated similarly but more    H.O
                                               ..P.

  simply, with a single stage of separation
  and no heating.
 Sludge from separators passes to a tank,
  from which it is removed by a pump
  capable of handling high-viscosity matter.
     1.6 Oil fuel transfer
 It may be mentioned here,
  because it is not always
  understood, that fuel is
  heated for combustion,
  not to raise its temperature
  but to bring it to a
  viscosity acceptable to the
  injectors or burners.
     Fuel pumps



      Engine
mu
Diesel engines consume Heavy Fuel Oil (HFO),
Marine Diesel oil (MDO) or Intermediate Fuel Oil (IFO).




                                        Fuel pumps
     S




                                           Engine
HFO is a residual oil that is made
suitable for driving Diesel engines by
adding certain flammable substances.

MDO is a high-grade fuel of
low viscosity that is used when the
vessel is manoeuvring.


 Modern Diesel engines are run
 on IFO, a fuel whose grade lies
 between that of HFO and MDO.
From the Heavy Fuel Oil bunkertank
the preheated fuel is led to the settling tank.



 Settling tank   HFO     HFO     MDO




                                     Fuel pumps


                                        Engine
In the settling tank water and impurities are
separated from the fuel and drained off.



     Settling tank    HFO   HFO   MDO

        Drain-valve




                                    Fuel pumps
 s




                                        Engine
From the settling tank the fuel is led through a
heater to preheat the fuel.



                 HFO     HFO      MDO




                                     Fuel pumps


                                        Engine
From the heater the fuel is led through a
separator (purifier / clarifier) to purify the fuel.



                   HFO       HFO      MDO




                                          Fuel pumps


                                            Engine
From the separator the fuel enters the
daily service tank for HFO.



              HFO     HFO     MDO




                                  Fuel pumps
 sound




                                    Engine
There are two daily service tanks, so that
one tank may be used while the other is
being filled.


             Daily service tank   Daily service tank

                  HFO                  HFO             MDO




                                                         Fuel pumps
 sound




                                                             Engine
From the daily service tank the fuel is pumped
to a heater by the low pressure fuel pump
(or “booster pump”).




                       HFO
                         s
                             HFO   MDO




                                     Fuel pumps


                                         Engine
From the heater the HFO is passed through
a viscosity regulator .



              HFO     HFO    MDO




                                 Fuel pumps


                                   Engine
From the viscosity regulator the fuel is passed
through a fuel strainer   , which filters the fuel.



                 HFO      HFO     MDO




                                      Fuel pumps


                                        Engine
From the fuel strainer the oil is led to the
fuel pumps in the engine.



                HFO      HFO     MDO




                                     Fuel pumps
 sound




                                       Engine
Diesel oil is used for manoeuvring      and is
stored in the MDO bunkertank.



               HFO     HFO     MDO




                                     Fuel pumps


                                       Engine
After the DO has been pumped up from
the bunkertank, the fuel passes through
a purifier .


             HFO     HFO     MDO




                                 Fuel pumps


                                   Engine
    From the purifier the DO enters the
             DO storage tank.



               HFO     HFO     MDO




                                  Fuel pumps
s




                                     Engine
From the DO service tank the fuel is led to the
high-pressure fuel pumps in the engine.




                HFO      HFO     MDO




                                    Fuel pumps
   s




                                       Engine
    A mixing tank is used for a gradual transition
    from HFO to DO.




                      HFO   HFO     MDO




                                        Fuel pumps
              sound




                                          Engine
Mixing tank
         The mixing tank, or “buffer tank”, can hold
         a quantity of fuel which will be circulated
         and led to the engine.



                        HFO     HFO     MDO




                                           Fuel pumps
                sound
Buffer tank

(Circulating tank)
                                              Engine
           The hot fuel fumes can escape through
           the air vent in the mixing tank.




                        HFO     HFO     MDO




                                           Fuel pumps
            s




Air vent                                      Engine
    HFO is a residual oil that is made suitable for
    driving Diesel engines by removing certain
    flammable substances.
            …..because:



    MDO is a low-grade fuel of high viscosity that
    is used when the vessel is manoeuvring.
             …..because:




    Modern Diesel engines are run on IFO, a fuel
    whose grade lies between that of HFO and
    MDO.

1
    From the Heavy Fuel Oil bunkertank    the fuel
    is led to the settling tank.



      Settling
       tank       HFO      HFO     MDO




                                         Fuel pumps


                                           Engine
2
        …..because:

    In the settling tank the fuel is drained off after it
    has been separated from water and impurities.



        Settling
         tank          HFO       HFO       MDO




                                                Fuel pumps


                                                  Engine
3
        …..because:

    From the settling tank the fuel is first led through a
    purifier and then through a separator.



       Settling
        tank          HFO       HFO      MDO




                                             Fuel pumps


                                                Engine
4
    From the separator the fuel enters the
    daily service tank.



    Settling
     tank        HFO       HFO      MDO




                                        Fuel pumps


                                             Engine
5
       …..because:

    There are two daily service tanks:
    one to preheat the fuel, the other to purify the fuel.



       Settling
        tank         HFO       HFO       MDO




                                             Fuel pumps


                                                Engine
6
    From the daily service tank the fuel is pumped to
    a heater by the booster pump.



       Settling
        tank        HFO       HFO      MDO




                                           Fuel pumps


                                             Engine
7
       …..because:

    From the heater the HFO is passed through a
    separator   .



       Settling
        tank         HFO     HFO     MDO




                                         Fuel pumps


                                            Engine
8
        …..because:


    A fuel strainer    preheats and filters the fuel.




       Settling
        tank          HFO     HFO       MDO




                                            Fuel pumps


                                               Engine
9
         …..because:

     From the fuel strainer the oil is led to the
     low pressure fuel pumps in the engine.



        Settling
         tank          HFO       HFO       MDO




                                               Fuel pumps


                                                    Engine
10
         …..because:


     Diesel oil is used for manoeuvring and is stored
     in three daily service tanks.



        Settling
         tank          HFO     HFO     MDO




                                           Fuel pumps


                                              Engine
11
     After the DO has been pumped up from the
     bunkertank, it is passed through a purifier.



        Settling
         tank         HFO      HFO       MDO




                                             Fuel pumps


                                               Engine
12
     …..because:

 From the purifier the DO enters the settling tank.




     Settling
      tank         HFO      HFO      MDO




                                         Fuel pumps


                                           Engine
13
        …..because:

     From the DO service tank the fuel is led through
     a separator, heater, viscosity controller and
     strainer to the fuel pumps in the engine.


        Settling
         tank         HFO      HFO     MDO




                                           Fuel pumps


                                              Engine
14
     …..because:

A mixing tank is used to drain off water and
impurities from the fuel.



    Settling
     tank          HFO     HFO      MDO




                                        Fuel pumps
  Mixing
   tank


                                          Engine
           …..because:

        The hot fuel fumes can escape through the
        air vent into the mixing tank.




          Settling
           tank          HFO    HFO      MDO




        Mixing
                                            Fuel pumps
         tank


                                               Engine
sound
                                                         16
          1.8 Bilge and ballast

 The essentials of the bilge and ballast system are
  simple .
 They consist of a bilge main in the engine room
  which is connected to one or more pumps and, also
  to the hole, tunnel and machinery space bilges by
  suitably placed valves; the pumps discharge
  overboard .
 A ballast main is similarly connected to a pump, the
  sea and to ballast tanks; the pump discharging
  overboard or to deep and peak tanks through the
  ballast main.
          1.8 Bilge and ballast

 In practice the use of oil fuel with the attendant
  need to retain the oil when discharging overboard,
  the need to provide adequate services in the event
  of breakdown or casualty without unreasonable
  duplication and to avoid accidental flooding, have
  all given rise to some elaboration of the system.
  Figure 1.7 is a diagrammatic arrangement showing
  bilge, ballast and oil-fuel filling.
Figure 1.7 diagram of bilge,
 ballast and oil fuel filling

				
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