10.1 Tanks for separated sludge and their pipework
Tanks for separated sludge, their pipework and pumps should
be designed as follows:
10.1.1 Size of tanks: see paragraph 8.
10.1.2 Tank heating system
Tanks for separated sludge should be equipped with tank heating
systems. The heating pipes should be arranged such that, seen from
the heating inlet, to start with they are arranged in a way of the
boundaries and then across the whole bottom area sufficiently high,
in order to avoid being covered totally by sediments in the tank.
The tank heating system should be designed such as to enable heating
of the oil sludge up to 60°C. The suction line from the sludge
tank to the pump should be provided with heat tracing.
10.1.3 Oil residue (sludge) drain tank
The tank for separated sludge or other waste oils may be arranged
as a separate oil residue (sludge) drain tank.
10.1.4 Pipelines from the heavy fuel oil purifier
to the tank
Whenever possible, the oil residue (sludge) tank should be located
below the heavy fuel oil purifier. If this is not possible, the oil
residue (sludge) holding tank should be situated close to the heavy
fuel oil purifier in such a way that the discharge line to the tank
can be installed at the maximum gradient. The pipelines should, wherever
possible, be straight or fitted with large radius elbows.
10.1.5 Suction line from the oil residue (sludge)
tank
The pump suction should be arranged so that the path to the
suction opening is as short as possible; or the oil residue (sludge)
tank should be mounted or designed, so that the oil residue (sludge)
moves down a slope towards the suction opening. The openings should
be placed as wide as possible in the frames above the tank bottom
in such a way that the oil sludge has free access to the suction line.
10.1.6 Oil residue (sludge) collecting pump and
pressure lines
The pump should be suitable for use with high viscosity oil
residue (sludge), e.g., “self-priming displacement pump”,
with suitable means for protection against dry running. It should
have a sufficient total head, and delivery rate to facilitate the
transfer of the daily sludge production onboard.
10.1.7 Oil residue (sludge) discharge pump and
pressure lines
The pump should be suitable for use with high viscosity oil
sludge, e.g., self-priming displacement pump', with suitable means
for protection against dry running. It should have a sufficient total
head, and be capable of discharging the tank within 4 to 8 hours.
The pressure side of the pump should only be connected to the
standard connection on deck and to oil residue (sludge) tank(s) and
to other sludge disposal means as listed in item 3.2 in the Supplement
to the IOPP Certificate.
10.1.8 Oil residue (sludge) tank design to facilitate
cleaning
Access holes should be arranged so that all areas of the tank
can be cleaned. An access hole should be sited on top of the tank
to facilitate the use of a portable pump.
10.1.9 Steaming-out lines
The oil residue (sludge) tanks should be fitted with steaming-out
lines for cleaning.