“The customer chose our Siwertell technology again, because they wanted a highly efficient continuous screw-type unloader, which was also capable of safely handling potentially explosive materials, such as sulphur,” says Anders Paulsson, Cargotec Sales Manager, Bulk Handling. “We have by far the most knowledge and experience of screw-type unloaders, and can offer them at competitive prices.”
Cargotec supplied Petrokimia Gresik with a ST640-DOB Siwertell ship unloader in 1996, and this latest contract will see it deliver the latest version of the same type within the next 13 months. The ship unloader will be erected at its operating site in Gresik, Indonesia and able to handle rock phosphate, sulphur, urea and ammonium sulphate at a rated capacity of 1,000t/h. Petrokimia plans to have the site running from mid 2013.
“With a totally enclosed system, our Siwertell unloaders offer customers an environmentally-friendly solution. Also, for handling sulphur, the unloader has a built-in safety mechanism; our award-winning 4S system,” highlights Mr Paulsson.
The 4S (Siwertell sulphur safety system) is designed to minimise the risk of explosions and detect fires. Cargotec now applies the 4S to all ship unloaders aimed for sulphur unloading, both those for larger ships and road-mobile unloaders for smaller ships.
To prevent explosions and fires, the Siwertell unit is equipped with nozzles that spray water at the inlet feeder and in the conveyor transfer points. An automatic lubrication system is installed to lubricate and cool down end bearings and intermediate bearings. There are also fire detectors along the conveying line, and when activated these automatically start the fire extinguishing system spraying water and stop the conveyors. This is vital to prevent fires entering the storage building. To manage any explosion, the conveyor’s steel casings are reinforced with extra-thick steel, and explosion-venting valves are fitted along the conveyors and dust collectors to relieve pressure.