Man B&W S80ME-C7, Project Manual

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MAN B&W 7.05
Page of 3
MAN Diesel
MAN B&W MC/MC-C, ME/ME-B/MEC/MEGI engines 198 39 512.3
Components for fuel oil system
Fuel oil centrifuges
The manual cleaning type of centrifuges are not to
be recommended, neither for attended machinery
spaces (AMS) nor for unattended machinery spac-
es (UMS). Centrifuges must be selfcleaning, either
with total discharge or with partial discharge.
Distinction must be made between installations for:
• Specific gravities < 0.99 (corresponding to ISO
827 and British Standard 6843 from RMA to
RMH, and CIMAC from A to Hgrades
• Specific gravities > 0.99 and (corresponding to
CIMAC Kgrades).
For the latter specific gravities, the manufacturers
have developed special types of centrifuges, e.g.:
Alfa Laval ........................................................Alcap
Westfalia ....................................................... Unitrol
Mitsubishi .............................................. EHidens II
The centrifuge should be able to treat approxi-
mately the following quantity of oil:
0.23 litres/kWh = 0.17 litres/BHPh
This figure includes a margin for:
• Water content in fuel oil
• Possible sludge, ash and other impurities in the
fuel oil
• Increased fuel oil consumption, in connection
with other conditions than ISO standard condi-
tion
• Purifier service for cleaning and maintenance.
The size of the centrifuge has to be chosen ac-
cording to the supplier’s table valid for the select-
ed viscosity of the Heavy Fuel Oil. Normally, two
centrifuges are installed for Heavy Fuel Oil (HFO),
each with adequate capacity to comply with the
above recommendation.
A centrifuge for Marine Diesel Oil (MDO) is not a
must, but if it is decided to install one on board,
the capacity should be based on the above rec-
ommendation, or it should be a centrifuge of the
same size as that for lubricating oil.
The Nominal MCR is used to determine the to-
tal installed capacity. Any derating can be taken
into consideration in borderline cases where the
centrifuge that is one step smaller is able to cover
Specified MCR .
Fuel oil supply pump
This is to be of the screw or gear wheel type.
Fuel oil viscosity, specified .... up to 700 cSt at 50 °C
Fuel oil viscosity maximum .......................000 cSt
Pump head ......................................................4 bar
Fuel oil flow .........................see ‘List of capacities’
Delivery pressure ............................................4 bar
Working temperature ................................... 00 °C
Minimum temperature .................................... 50 °C
The capacity stated in ‘List of capacities’ is to be ful-
filled with a tolerance of: ÷0% to +5% and shall also
be able to cover the backflushing, see ‘Fuel oil filter’.
Fuel oil circulating pump
This is to be of the screw or gear wheel type.
Fuel oil viscosity, specified .... up to 700 cSt at 50 °C
Fuel oil viscosity normal ................................20 cSt
Fuel oil viscosity maximum .......................000 cSt
Fuel oil flow .........................see ‘List of capacities’
Pump head ......................................................6 bar
Delivery pressure ..........................................0 bar
Working temperature ................................... 50 °C
The capacity stated in ‘List of capacities’ is to be ful-
filled with a tolerance of: ÷0% to +5% and shall also
be able to cover the backflushing, see ‘Fuel oil filter’.
Pump head is based on a total pressure drop in
filter and preheater of maximum .5 bar.