Both the port and starboard slop tanks are fitted with internal grid type heating coils. The port slop tank has eight coils fitted while the starboard slop tank has only two coils fitted. The cargo oil tanks each have three coils.
The coils are supplied with 0.9MPa saturated steam from the engine room and the condensate return passes through steam traps back to the atmospheric condenser and subsequently back to the feed filter tank. It is possible to isolate each section of heating coils as required.
The heating coils inside the slop tanks are made from non-ferrous material to prevent corrosion when in contact with salt water.
The following table shows the heating capacity for each tank:
|Tank||Tank Volume 98% (m3)||Maximum Steam Consumption (kg/h)||Heating Coil Area (m2)||Heating Coil Ratio||Heating Coil Length (m)||No. of Coils|
|No.1 Port and Starboard COT||8,245||2,095||64.14||0.0090||358.1||3|
|No.2 Port and Starboard COT||9,961||2,420||75.74||0.0086||463.3||3|
|No.3 Port and Starboard COT||10,011||2,430||76.17||0.0086||463.8||3|
|No.4 Port and Starboard COT||10,011||2,430||76.17||0.0086||463.8||3|
|No.5 Port and Starboard COT||10,011||2,430||76.17||0.0086||463.8||3|
|No.6 Port and Starboard COT||9,658||2,345||72.99||0.0086||439.6||3|
|Slop Tank Starboard||2,353||650||16.49||0.0098||149.6||2|
|Slop Tank Port||2,353||10,835||91.98||0.0505||217.3||8|
The heating system for the port slop tank is designed to maintain the cargo oil at a temperature of 66°C. For water washing operations with a capacity of 50% sea water, it is also able to raise the temperature up from 15°C to 66°C over 24 hours while on passage based on an ambient air temperature of 2°C and a sea water temperature of 5°C.
Deck Seal Heating System
The deck seal is fitted with a steam heating coil to ensure the sea water sealing water does not freeze during ship operations in cold climates. There is a small branch off the heating line to the deck seal which is used for trace heating the sea water sealing water supply to the deck seal unit. The steam supply to the deck seal is independent from the steam heating line for the cargo oil and slop tanks and tank cleaning heater.