Approximate Flow In Hcu Leakage Drain; Heating Of Drain Pipe - Man B&W S80ME-C7 Project Manual

MAN B&W
The HCU has a leakage drain from the support
console of clean fuel oil through 'AD'.
The flow rate in litres is approximately as listed in
Table 7.0.0.
Engine
K08ME-C, K98ME/ME-C, S90ME-C
K90ME/ME-C, S/K80ME-C, S70ME-C/
ME-GI, L70ME-C, S65ME-C/ME-GI
S/L60ME-C, S60ME-GI, S50ME-C,
S50/40/35ME-B
Table 7.01.01: Approximate flow in HCU leakage drain.
The main purpose of the drain 'AF' is to collect
pure fuel oil from the fuel pumps as well as the
unintentional leakage from the high pressure
pipes. The drain oil is lead to a 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 pipes.
MAN B&W ME/ME-B/MEC/MEGI engines

Heating of drain pipe

Owing to the relatively high viscosity of the heavy
fuel oil, it is recommended that the drain pipe and
the tank are heated to min. 50 °C, whereas the
HFO pipes as basic are heated by steam through
flanges 'BX' and 'BF'.
Flow rate,
The drain pipe between engine and tank can
litres/cyl. h.
be heated by the jacket water, as shown in Fig.
.5
7.0.0. 'Fuel pipe heating' as flange 'BD'.
0.75
The size of the sludge tank is determined on the
basis of the draining intervals, the classification
0.60
society rules, and on whether it may be vented
directly to the engine room.
This drained clean oil will, of course, influence the
measured SFOC, but the oil is thus not wasted,
and the quantity is well within the measuring ac-
curacy of the flowmeters normally used.
For external pipe connections, we prescribe the
following maximum flow velocities:
Marine diesel oil .......................................... .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
tion 7.06.
An emulsification arrangement for the main en-
gine is described in our publication:
550-0063 'Operation on Heavy Residual Fuels
This publication is available at our Internet address:
www.mandiesel.com under 'Quicklinks' → 'Tech-
nical Papers', from where it can be downloaded.
MAN Diesel
emission. This is further described in sec-
x
and Destilates. Guidelines for Fuels
and Lubes'
7.01
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