Upload
tabitha-ray
View
252
Download
6
Embed Size (px)
Citation preview
Ship-Type Operations
UNITAS
Session 11
Tankers
Introduction
• Oil tankers
• Chemical tankers
• Gas carriers
Ship-Type Operations
UNITAS
Session 11
Chemical tankers
• As for oil tanker, normally smaller vessels.
• Design arrangements influenced by
IBC Code and damage stability
requirements.
• Cargo heating such as on asphalt
carriers brings problems of thermal
expansion and can create problems
in the cargo holds.
Ship-Type Operations
UNITAS
Session 11 Chemical Tankers
Cargo transported:
• Easy Chemicals such as:
Acetone, Xylene
Methanol, Vegetable oils
Edible Liquids
Relevant Rules:
• SOLAS 74
• MARPOL Annex II
Tanker FLS
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
Cargo transported:
• Chemicals: Acids, alcohols,
Carbon Disulfide, etc
Relevant Rules:
• SOLAS 74, as amended
• IBC Code,
• MARPOL Annex II
Ship-Type Operations
UNITAS
Session 11 Chemical Tankers
3 CATEGORIES OF NLS (Revised MARPOL Annex II)
X Major Hazard
YHazard
Z Minor Hazard
OSOther substances
Present no harm
• IBC Ch.17, types 1,2 & 3
Prohibition of
discharge
Limitation onquality & quantityof discharge
Less stringentrestriction on discharge
Not subject to
requirements of Annex II
• IBC Ch.17 or 18
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
Hazards of chemicals
• FLAMMABILITY
• TOXICITY
• HEALTH
• CORROSIVITY
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
Hazards of chemicals (2)
REACTIVITY
• With other products• With water
• With themselves• With oxygen
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
Hazards of chemicals (3)
POLLUTION
• Water pollution
• Air pollution
• Marine pollution
• Categorization
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
CARRIAGE OF DANGEROUS CHEMICALS IN BULK
• BCH CODE (1971)
• IBC CODE (1983)
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
SHIP SURVIVAL CAPABILITY
• Type 1 Ship: maximum preventive measures
• Type 2 Ship: significant preventive measures
• Type 3 Ship: moderate preventive measures
Ship-Type Operations
UNITAS
Session 11 Chemical Tankers Cargo Tanks location
TYPE 1 TYPE 2
Available space• • for cargo
tanks
760mm
> B/15 OR 6 M
> B/5 OR 11.5 M
Available spacefor cargo
tanks
S.L.L.
760mm
Available spacefor cargo
tanks
S.L.L.
TYPE 3
S.L.L.
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
STANDARD OF DAMAGE
• Type 1
• Type 2, L>150m Damage anywhere
• Type 3, L>225m
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
STANDARD OF DAMAGE (1)
• Type 2, L<=150m
• Type 3, L > 125mAs per type 1, but no damages to E.R bulkheads
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
STANDARD OF DAMAGE (2)
• Type 3, L<= 125m: As per Type 1, but no damages in E.R
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
CARGO
TRANSFER
DEEPWELL CARGO
PUMP
(Source: FRAMO)
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
• INERTING - REPLACES AIR IN THE CARGO TANK BEFORE LOADING THE CARGO. INERTING MAY BE CARRIED OUT USING: BY INERT GAS FROM THE COMBUSTION OF FUEL BY NITROGEN
• USUALLY COMBUSTION GASES, DUE TO HIGH IMPURITY CONTENT, AREONLY USED FOR GAS FREEING PRIOR TO INERTING WITH NITROGEN. INSTALLATIONS ARE AS PER OIL TANKERS INSTALLATIONS, EXCEPT THAT THERE IS DECK WATER SEAL AND THE SYSTEM IS PROVIDED WITHDRYING TOWERS.
INERTING AND PADDING SYSTEMS
Ship-Type Operations
UNITAS
Session 11
Chemical Tankers
INERTING AND PADDING SYSTEMS
• PADDING - REPLACES CARGO VAPOUR TO AVOID CHEMICAL REACTION WITH AIR.
• NITROGEN FOR PADDING OR INERTING IS OBTAINED FROM HIGH PRESSURE
NITROGEN BOTTLES OR FROM A NITROGEN GENERATION PLANT.
• NITROGEN FROM HIGH PRESSURE BOTTLES IS SENT TO THE CARGO TANK FOR
PADDING AT 0.1 BAR, TO THE BALLAST TANK FOR INERTING AT 0.07 BAR AND TO THE
BALLAST TANK FOR INERTING AT 0.07 BAR AND TO THE CARGO PIPING AT 7 BAR.
••
• ON NEWER SHIPS, MEMBRANE SYSTEMS DRIVEN BY AIR COOLED COMPRESSORS ARE
USED.
Ship-Type Operations
UNITAS
Session 11 Chemical Tankers
• Combustionair fan
• IG Generator
• Pressure/VacuumBreaker
• Oil FuelPump • Deck water seal
INERT
GAS
SYSTEM
(Source:SMITOVENS)