MAN B&W S65ME-C8.2-GI-TII, Project Manual

Page: 175 / 395

MAN B&W 7.01
Page 3 of 3
MAN Diesel MAN B&W K98ME/ME-C, S90ME-C, K90ME/ME-C,
G/S80ME-C, K80ME-C, G70ME-C, S70ME-C/-GI, L70ME-C,
S65ME-C/-GI, G60ME-C, S60ME-C/-GI/ME-B, L60ME-C 198 76 609.3
Drain of clean fuel oil from HCU, pumps, pipes
The HCU Fuel Oil Pressure Booster has a leakage
drain of clean fuel oil from the umbrella sealing
through ‘AD’ to the fuel oil drain tank.
The flow rate in litres is approximately as listed in
Table 7.01.02.
Drain of contaminated fuel etc.
Leakage oil, in shape of fuel and lubricating oil
contaminated with water, dirt etc. and collected
by the HCU Base Plate top plate, is drained off
through the bedplate drains ‘AE’.
Drain ‘AE’ is shown in Fig. 8.07.02.
Heating of fuel drain pipes
Owing to the relatively high viscosity of the heavy
fuel oil, it is recommended that the drain pipes
and the fuel oil drain tank are heated to min. 50 °C,
but max. 100 °C.
The drain pipes between engine and tanks can
be heated by the jacket water, as shown in Fig.
7.01.01 ‘Fuel oil system’ as flange ‘BD’.
Fuel oil flow velocity and viscosity
For external pipe connections, we prescribe the
following maximum flow velocities:
Marine diesel oil .......................................... 1.0 m/s
Heavy fuel oil ............................................... 0.6 m/s
The fuel viscosity is influenced by factors such as
emulsification of water into the fuel for reducing
the NO
x
emission. This is further described in Sec-
tion 7.06.
An emulsification arrangement for the main engine
is described in our publication:
Exhaust Gas Emission Control Today and
Tomorrow
Further information about fuel oil specifications is
available in our publication:
Guidelines for Fuels and Lubes Purchasing
The publications are available at www.marine.
man.eu
→
’Two-Stroke’
→
’Technical Papers’.
Engine
Flow rate,
litres/cyl. h.
HFO 12 cSt
K98ME/ME-C, 0.65
S90ME-C, K90ME/ME-C 0.55
G/S/K80ME-C 0.50
G/S/L70ME-C, S70ME-C-GI, S65ME-C/-GI 0.40
G/S/L60ME-C, S60ME-C-GI, S60ME-B 0.30
This drained clean oil will, of course, influence the
measured SFOC, but the oil is not wasted, and the
quantity is well within the measuring accuracy of
the flowmeters normally used.
The main purpose of the drain ‘AD’ is to collect
fuel oil from the fuel pumps. As a safety measure
for the crew during maintenance, an overhaul
drain from the umbrella leads clean fuel oil from
the umbrella directly to drain ‘AF’. Also washing
water from the cylinder cover and the baseplate is
led to drain ‘AF’.
The drain oil is led to a sludge tank and can be
pumped to the Heavy Fuel Oil service tank or to
the settling tank.
The ‘AF’ drain is provided with a box for giving
alarm in case of leakage in a high pressure pipe.
The size of the sludge tank is determined on the
basis of the draining intervals, the classification
society rules, and on whether it may be vented
directly to the engine room.
Drains ‘AD’, ‘AF’ and the drain for overhaul are
shown in Fig. 7.03.01.
Table 7.01.02: Approximate flow in HCU leakage drain.