LPG tanker CELANOVA
According Significant Ships of 2003
CELANOVA has been built for service around the southern Spanish coasts and the Balearic Islands. She is a type 2G gas tanker designed to transport semi-refrigerated cargoes (-48°C, 6.5bar) in five type C, independent, cylindrical stainless steel tanks, carried on supports and surrounded by void spaces.
A Tractebel Gas Engineering handling and re-liquefaction plant is installed to deal with gases including propane, propane/butane, anhydrous ammonia, vinyl chloride monomer, i-butane, n-butane, butane, and butadiene. A direct-working system is employed, where reliquefaction of vaporised cargo is effected by means of three systems – a pressure decrease in the tanks, compression with condensation against seawater and expansion back into the tanks.
Three Sulzer direct-drive, labyrinth piston-type cargo compressors are provided, together with suction separators, flash drum-type cargo economisers, and LPG condensers. These, and the cargo heater/evaporator, and fresh water heating/cooling system, are fitted with titanium plate heat exchangers, and are installed in a deckhouse abaft the forecastle.
The cargo is handled using a 150m3/h electrically-driven deepwell pump in each tank, ensuring loading and unloading times, with vapour return, of around 10 hours. Two grades of cargo can be transported at the same time, and each can be cooled simultaneously. Two 150m3/h booster pumps are also fitted and arranged to work in series either with one or two cargo pumps.
A hydraulically-operated valve quick-closing system, using actuators fitted to valves in the cargo and vapour lines at crossovers and tank domes, operates to provide an emergency stop system. Other safety features include a detection system for identifying gas concentration in hazardous areas of the plant and inert gas installation, fitted with two absorbers filled with carbon monoxide sieves in the nitrogen production equipment.