Section
3 Fuel oil burning arrangements
3.1 Oil burning units
3.1.1 All
oil burning equipment is to be capable of operating at defined power/rating
levels where specified by the Owner/Operator. Confirmation by the
manufacturer of this capability is to be provided to LR including
the specified power/rating parameters, and operating and maintenance
regimes. See also
Pt 5, Ch 1, 3.1 Availability for operation 3.1.2.
3.1.2 Where
steam is required for the main propelling engines, or where steam
or thermal oil is required for auxiliary machinery for essential services,
or for heating of heavy fuel oil and is generated by burning fuel
oil under pressure, there are to be not less than two oil burning
units. For auxiliary boilers, a single oil burning unit may be accepted,
provided that alternative means, such as an exhaust gas boiler or
composite boiler, are available for supply of essential services.
Where the oil burning unit is not of the monobloc type (i.e. separate
register and oil supply unit), each oil burning unit is to comprise
a pressure pump, suction filter, discharge filter and, when required,
a heater.
3.1.3 In
installations consisting of two or more oil burning units, the number,
arrangement and capacity of such units is to be capable of supplying
sufficient fuel to allow the steam to be generated or thermal oil
heated, as applicable to provide essential services with any one unit
out of action.
3.1.4 Unit
pressure pumps are to be entirely separate from the feed, bilge or
ballast systems.
3.1.5 In
dual fuel oil burning systems for boilers which are primarily designed
for operation with residual fuel oil grades, arrangements are to be
such that atomising steam cannot be used in combination with distillate
fuel oil grades where the burner arrangements have not been designed
for such use.
3.1.6 In
all dual fuel oil burning systems for boilers, the manufacturer of
the combustion equipment is to ensure that the full system, including
control and monitoring systems, is capable of continuous operation
in all conditions for each fuel grade.
3.1.7 Whenever
the fuel oil burning units are stopped, shut-off arrangements for
fuel oil to the units are to be provided as follows:
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If the supply
fuel oil is under pressure during shut-off to oil burning units, duplicated
shut-off valves in series are to be fitted. Arrangements are to be
such to allow manual testing for leakage from each of the valves in
the installed condition, the test arrangement is to be such to prevent
inadvertent operation, and any discharges are to be led to a safe
position to ensure that discharge of leakage oil does not present
an ignition hazard.
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If arrangements
are such that fuel oil pressure is released through drainage during
fuel oil shut-off to oil burning units, a single shut-off device may
be accepted subject to approval by LR.
3.1.8 When
combined air and fuel/steam/air combustion systems are used for multiple
boiler installations, they are to be such that single boiler operation
will not be adversely affected by the operation of another boiler
system at any time.
3.1.9 Arrangements
are to be such that furnace prepurging is completed prior to any burner
ignition sequence. The purge time is to be based on a minimum of 4
air changes of the combustion chamber, furnace and uptake spaces.
The purge timing is to take account of the air flow rate and the sequence
is not to commence until all air registers and dampers, as applicable,
are fully open and the forced draft fans are operating.
3.1.10 The
effect of multiple light-off failures is to be assessed and the need
to lock out further ignition sequences established. The manufacturer’s
recommended procedures are to be followed before further attempts
to ignite the boiler are made. These procedures are to be displayed
at the ignition control positions and included in the warning notice
required by Pt 5, Ch 14, 3.1 Oil burning units 3.1.11.
3.1.11 Means
are to be provided so that, in the event of flame failure, the fuel
oil supply to the burner(s) is shut-off automatically, and an alarm
is given, see
Pt 5, Ch 10, 18.3 Main, auxiliary and other boilers, Pt 5, Ch 14, 12.2 Thermal fluid heaters and Pt 5, Ch 14, 12.3 Incinerators, as applicable.
3.1.12 It
is to be demonstrated to the Surveyor's satisfaction during trials
that burner shut-off times due to flame failure comply with the following
requirements, and details of the procedures and means used to set
this time interval are to be submitted for consideration:
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The time interval
at burner start up between the burner fuel oil valve(s) being opened
and then closed in the event of flame failure is to be long enough
to allow a stable flame to be established and detected under normal
operational circumstances, but is to be set to minimise the quantity
of fuel oil delivered to the furnace and the possibility of subsequent
damage as a result of unintended ignition.
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The time interval
between flame failure detection and closing of burner fuel oil valve(s)
is to be long enough to prevent shutdown due to incorrect detection
of a flame failure under normal operational circumstances, but is
to be set to minimise the quantity of unburned fuel oil delivered
to the furnace and the possibility of subsequent damage as a result
of unintended ignition.
3.1.13 A
warning notice is to be fitted in a prominent position at every oil
burning unit local manual control station which specifies that burners
operated with manual or local overrides in use are only to be ignited
after sufficient purging of the furnace and of any additional precautions
required when operating in this condition.
3.2 Gravity feed
3.2.1 In
systems where oil is fed to the burners by gravity, duplex filters
are to be fitted in the supply pipeline to the burners and so arranged
that one filter can be opened up when the other is in use.
3.3 Starting-up unit
3.3.1 A starting-up
fuel oil unit, including an auxiliary heater and hand pump, or other
suitable starting-up device, which does not require power from shore,
is to be provided.
3.4 Steam connections to burners
3.4.1 Where
burners are provided with steam purging and/or atomising connections,
the arrangements are to be such that fuel oil cannot find its way
into the steam system in the event of valve leakage.
3.5 Burner arrangements
3.5.1 The
burner arrangements are to be such that a burner cannot be withdrawn
unless the fuel oil supply to that burner is shut off, and that the
oil cannot be turned on unless the burner has been correctly coupled
to the supply line.
3.6 Quick-closing valve
3.6.1 A quick-closing
master valve is to be fitted to the oil supply to each boiler manifold,
suitably located so that the valve can be readily operated in an emergency,
either directly or by means of remote control, having regard to the
machinery arrangements and location of controls.
3.7 Spill arrangements
3.7.1 Provision
is to be made, by suitable non-return arrangements, to prevent oil
from spill systems being returned to the burners when the oil supply
to these burners has been shut off.
3.8 Alternately-fired furnaces
3.8.1 For
alternately-fired furnaces of boilers using exhaust gases and fuel
oil, the exhaust gas inlet pipe is to be provided with an isolating
device and interlocking arrangements whereby fuel oil can only be
supplied to the burners when the isolating device is closed to the
boiler.
3.9 Fuel oil treatment for supply to main and
auxiliary engines and gas turbines
3.9.1 A suitable
fuel treatment plant that may include filtration, centrifuging and/or
coalescing is to be provided to reduce the level of water and particulate
contamination of the fuel oil to within the engine or gas turbine
manufacturer's limits for inlet to the combustion system. The capacity
and arrangements of the treatment plant is to be suitable for ensuring
availability of treated fuel oil for the maximum continuous demand
of the propulsion and electrical generating plant.
3.9.2 Two or more treatment systems are to be provided as part of the fuel
treatment plant such that failure of one system will not render the other system(s)
inoperative. Arrangements are to ensure that the failure of a treatment system will not
interrupt the supply of clean fuel oil to engines or gas turbines used for propulsion
and electrical generating purposes where treatment plant is installed between fuel oil
service tanks and the inlet to the combustion system. Any treatment equipment in the
system is to be capable of being cleaned without interrupting the flow of treated fuel
to supply the combustion system.
3.9.3 Centrifuges
used for fuel oil treatment are to be type tested for their intended
usage when installed on board a ship in accordance with a standard
acceptable to LR.
3.9.4 Where
heating of the fuel oil is required for the efficient functioning
of the fuel oil treatment plant, a minimum of two heating units are
to be provided. Each heating unit is to be of sufficient capacity
to raise and maintain the required temperature of the fuel oil for
the required delivery flow rate.
3.9.5 Heating
units may be in circuit with separate treatment systems or provided
with connections such that any heating unit can be connected to any
treatment system.
3.9.6 Where
heating of the fuel oil is required for combustion, not less than
two pre-heaters are to be provided, each with sufficient capacity
to raise the temperature of the fuel to provide a viscosity suitable
for combustion.
3.9.7 Filters and/or coalescers are to be fitted in the fuel oil supply lines to
each engine and gas turbine to ensure that only suitably filtered oil is fed to the
combustion system. The arrangements are to be such that any unit can be cleaned without
interrupting the supply of filtered oil to the combustion system.
3.10 Booster pumps
3.10.1 Where
an fuel oil booster pump is fitted, which is essential to the operation
of the main engine, a standby pump is to be provided.
3.10.2 The
standby pump is to be connected ready for immediate use but where
two or more main engines are fitted, each with its own pump, a complete
spare pump may be accepted provided that it is readily accessible
and can easily be installed.
3.11 Booster pumps when operating in emissions control areas
3.11.2 The fuel oil booster pumps which are fitted in compliance with 3.10 are
acceptable for use in emissions control areas where these pumps are each suitable to
operate on low sulphur marine fuels at the required capacity for normal operation of
propulsion machinery.
3.11.3 When the fuel oil booster pumps which are fitted in compliance with Pt 5, Ch 14, 3.10 Booster pumps are
suitable to operate on low sulphur marine fuels but one pump alone is not capable of
delivering these fuels at the required capacity, two pumps may operate in parallel to
achieve the required capacity for normal operation of propulsion machinery. In this
case, one additional (third) pump is to be provided. The additional pump shall, when
operating in parallel with one of the pumps in Pt 5, Ch 14, 3.10 Booster pumps, be
suitable for and capable of delivering these fuels at the required capacity for normal
operation of the propulsion machinery.
3.12 Fuel valve cooling pumps
3.13 Oil-fired galleys
3.13.1 The
fuel oil tank is to be located outside the galley and is to be fitted
with approved means of filling and venting.
3.13.2 The
fuel supply to the burners is to be controlled from a position which
will always be accessible in the event of a fire occurring in the
galley.
3.13.3 The
galley is to be well ventilated.
3.13.4 When
liquefied petroleum gas is used, bottles are to be stored on the open
deck or in a well ventilated space which only opens to the open deck.
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