Components For Fuel Oil System; Fuel Oil Centrifuges; Fuel Oil Supply Pump; Fuel Oil Circulating Pump - Man B&W S50ME-B9.3-TII Project Manual

MAN B&W

Components for Fuel Oil System

Fuel oil centrifuges

The manual cleaning type of centrifuges are
not to be recommended. Centrifuges must be
selfcleaning, either with total discharge or with
partial discharge.
Distinction must be made between installations
for:
• Specific gravities < 0.991 (corresponding to ISO
8217 and British Standard 6843 from RMA to
RMH, and CIMAC from A to Hgrades
• Specific gravities > 0.991 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
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 condition
• 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. However, MAN Diesel & Turbo recommends
that at least one of the HFO purifiers can also
treat MDO.
MAN B&W MC/MC-C, ME/MEC/ME-B/GI engines
If it is decided after all to install an individual puri-
fier for MDO on board, the capacity should be
based on the above recommendation, or it should
be a centrifuge of the same size as that for HFO.
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 ......................1,000 cSt
Pump head ......................................................4 bar
Fuel oil flow ........................ see 'List of Capacities'
Delivery pressure ............................................4 bar
Working temperature ................................... 100 °C
Minimum temperature .................................... 50 °C
The capacity stated in 'List of Capacities' is to be ful-
filled with a tolerance of: ÷0% to +15% 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 ......................1,000 cSt
Fuel oil flow ........................ see 'List of Capacities'
Pump head ......................................................6 bar
Delivery pressure .......................................... 10 bar
Working temperature ................................... 150 °C
The capacity stated in 'List of Capacities' is to be ful-
filled with a tolerance of: ÷0% to +15% 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 1.5 bar.
MAN Diesel
7.05
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