This section is available on request - MAN Diesel & Turbo

MAN B&W 7.01
The HCU has a leakage drain from the support
console of clean fuel oil through ‘AD’.
The flow rate in litres <strong>is</strong> approximately as l<strong>is</strong>ted in
Table 7.0 .0 .
Flow rate,
Engine
litres/cyl. h.
K 08ME-C, K98ME/ME-C, S90ME-C . 5
K90ME/ME-C, S/K80ME-C, S70ME-C/
ME-GI, L70ME-C, S65ME-C/ME-GI 0.75
S/L60ME-C, S60ME-GI, S50ME-C,
S50/40/35ME-B 0.60
Table 7.01.01: Approximate flow in HCU leakage drain.
The main purpose of the drain ‘AF’ <strong>is</strong> to collect
pure fuel oil from the fuel pumps as well as the
unintentional leakage from the high pressure
pipes. The drain oil <strong>is</strong> lead to a tank and can be
pumped to the Heavy Fuel Oil service tank or to
the settling tank.
The ‘AF’ drain <strong>is</strong> provided with a box for giving
alarm in case of leakage in a high pressure pipes.
Heating of drain pipe
Page 3 of 3
Owing to the relatively high v<strong>is</strong>cosity of the heavy
fuel oil, it <strong>is</strong> 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’.
The drain pipe between engine and tank can
be heated by the jacket water, as shown in Fig.
7.0 .0 . ‘Fuel pipe heating’ as flange ‘BD’.
The size of the sludge tank <strong>is</strong> determined on the
bas<strong>is</strong> of the draining intervals, the classification
society rules, and on whether it may be vented
directly to the engine room.
<strong>Th<strong>is</strong></strong> drained clean oil will, of course, influence the
measured SFOC, but the oil <strong>is</strong> thus not wasted,
and the quantity <strong>is</strong> well within the measuring accuracy
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 v<strong>is</strong>cosity <strong>is</strong> influenced by factors such as
emulsification of water into the fuel for reducing
the NO x em<strong>is</strong>sion. <strong>Th<strong>is</strong></strong> <strong>is</strong> further described in <strong>section</strong>
7.06.
An emulsification arrangement for the main engine
<strong>is</strong> described in our publication:
55 0-0063 ‘Operation on Heavy Residual Fuels
and Destilates. Guidelines for Fuels
and Lubes’
<strong>Th<strong>is</strong></strong> publication <strong>is</strong> <strong>available</strong> at our Internet address:
www.mandiesel.com under ‘Quicklinks’ → ‘Technical
Papers’, from where it can be downloaded.
MAN B&W ME/ME-B/ME�C/ME�GI engines 198 42 28�2.6
MAN Diesel