MacGregor, part of Cargotec, has secured a new order for autonomous loading and unloading systems for an 8700dwt cement carrier to be built for Japanese shipowner Taiheiyo Kisen Kaisha Ltd.
The 109m vessel will have four cargo holds, each divided into two compartments. The cement handling system is designed to carry up to three grades of cement in each shipment.
During loading operations, the ship's deck-mounted receiving aeroslide is connected to the shore facilities by flexible bellows. Loading can be achieved on either side of the vessel.
The cement is then transferred to two short intermediate aeroslides by means of hydraulically-actuated flow control gates. These transfer the cargo to two reversible horizontal screw conveyors. One moves the cement forward to holds 1 and 2; the other serves holds 3 and 4. A combination of hydraulically-actuated sliding gates, flexible connections, hydraulically-actuated flow dividers and transfer aeroslides complete the delivery of the cement to the selected drop off points. Maximum level guards indicate when the holds are full, while pneumatically-operated shut-off valves avoid contamination between different grades of cement.
Sloping aeration panels installed on the tanktop of each hold are the first elements in the discharge system. Air blown through the panels fluidises the cement, allowing it to flow towards the centre of the hold, where it feeds into a vertical screw conveyor equipped with two remote-controlled flow control gates.
At deck level the cement returns to the reversible horizontal screw conveyors and is conveyed to a buffer hopper inside the pump room, located amidships. From the hopper the blow pump system transfers the cement to a silo ashore via two pipes. Dust collectors are installed on deck.
"The totally enclosed cement handling arrangements will ensure flexible, efficient and clean cargo operations," says Anders Berencsy, Sales Manager, Selfunloaders at MacGregor. "An additional benefit is that the computer-controlled systems are programmed for automatic operation by just one person."