Minimising the impact of imports

Karl Woodhouse, SAMSON Materials Handling, UK, considers the structural and environmental considerations of importing cement clinker at a bulk terminal in Abidjan. Recently, SEA-invest began developing a new facility at the Port of Abidjan, Ivory Coast, to provide an efficient unloading operation of cement bulks. The scope of this project includes a rail-mounted SAMSON Eco Hopper, which discharges via two outlets to either a high-level quayside conveyor at a rate of 1200 tph (which in turn links through a transfer tower to several new cement plants) or via a dedicated outlet direct to trucks at 700 tph. Environmental considerations are a primary concern for the development of this project. SEA-invest&rsquo;s bulk operations began with handling coal and scrap and diversified over the years to handling a variety of cargoes, including fruit and liquids as well as dry bulks. The SEA-invest Group is now one of the world's largest terminal operators with operations spanning over 25 ports in eight countries. The group engages in a variety of related fields, such as stevedoring and warehousing, and is dedicated to providing the highest level of service and flexibility to customers.Proposed layout of new terminal. The group serves a wide range of industries from steel and power to minerals and cement. As regional infrastructure develops, more demand is placed on building products, such as cement. Several new cement plants have been established and these require a reliable supply of materials, such as clinker and granulated blast furnace slag. The bulk terminal in Abidjan is an ideal hub for the cement industry. The port itself is situated on a lagoon off the Atlantic Ocean and is connected inland via road and rail networks providing clients with an established distribution route.Abidjan terminal The SEA-invest bulk terminal in the Ivory Coast is fully equipped to deal with all types of dry bulk and boasts 24 000 m&sup2; of covered storage, three mobile cranes, dedicated hoppers and conveyors. A variety of dry bulks are already passing through this terminal but further opportunities for developing the cement business have been identified.The group aims to encourage the growth of local economies and increase the attractiveness of ports. In order to do this, the company promises to invest in the modernisation of port infrastructure, provide logistical innovation and improve productivity whilst respecting the environment and training personnel.Example of rail mounted SAMSON Eco Hopper. For the development of the bulk terminal, SEA-invest selected a SAMSON Eco Hopper to increase efficient unloading of cement bulks, such as clinker, gypsum and slag. It is crucial to design import hoppers to suit the geographical and individual needs of the installation site. Tide variations at the Port of Abidjan are very low therefore modifying the discharge distance between the grab and the Eco Hopper will not pose difficulties for the operator. The quay is open to the elements. The hopper must be able to withstand marine air and strong winds that can reach up to 150 km/hr. It must also be able to operate in temperatures ranging from 0 &ndash; 50&deg;C.To provide a sturdy and long-lasting piece of equipment and to withstand the weather conditions, the hopper is finished with a marine specification paint to provide a suitable finish that will protect the equipment from the aggressive environment. Additionally storm anchors are set around the base of the hopper to provide support during high winds.Environmental impactEnvironmental impact is a key concern when choosing an import hopper, and is also a special key issue for SAMSON Materials Handling. As governments, port authorities and port operators are under increasing pressure to operate as environmentally responsibly as possible, equipment manufacturers must provide them with a solution that not only conforms to environmental standards but also performs well. A variety of dust reduction and containment measures will not only limit fugitive dust but will also reduce material wastage.The dust reduction measures employed on the hopper start with a flared shroud located around the grab discharge zone, which limits dust escaping and is designed to withstand cross-winds. Dust filters are situated around the hopper to clean the air as material is released from the grab. Material collected in the dust filters is then returned to the product flow.Illustration of the Flex-Flap system.As material falls into the hopper it passes through the Flex-Flap system. This effective device plays a considerable role in keeping fugitive dust to a minimum. Rubber flaps are supported on a steel frame. The weight of the material pushes through the flaps. As the material takes the space within the lower part of the hopper, displaced air rushes up and closes the flaps thus limiting the escape of dust.Rubber seals and dust filters are located at key areas, such as where the hopper joins with the discharge chute for truck loading and where the hopper joins the head chute leading to the high-level quayside conveyor.Truck loading takes place in an area enclosed by entry and exit curtains in order to further contain any fugitive dust. SAMSON is providing SEA-invest with stringent performance guarantees regarding dust emissions. These will be measured at critical areas, focusing at each transfer point to ensure the emissions are within agreed tolerances.The quay and warehouse area where the new hopper is to be installed are already in place. Installation and operation of the new hopper must take into consideration the proximity of the warehouses, access points and circulation routes for receiving trucks. The hopper is designed to accommodate the grab dimension and capacity of the mobile harbour cranes, ensuring the performance criteria is met.The overall height of the SAMSON Eco Hopper had to take into consideration the access clearance height required by the trucks as well as the height required to discharge to the high-level quayside conveyor plus the operational lift height of the mobile harbour crane. These heights and distances from pre-existing structures and other equipment are fixed; therefore SAMSON engineered the most efficient design to fit to these restrictions, which was crucial in providing SEA-invest with the optimum solution for their project.The hopper will be installed on the existing rails system, with a four wheel arrangement to each of the four corners of the legs of the main structure. Each leg of the structure is supported by one driven and three non-driven rail wheels to propel the equipment for positioning along the quayside suitable for optimising the unloading of any of the vessel&rsquo;s holds, following the unloading pattern determined by the ship&rsquo;s captain.ConclusionPorts are busy places where equipment must be of a robust design and tailored to the specifics of an application and materials being handled. In addition to SAMSON designing all of its equipment to the relevant design and safety standards, the Eco Hopper also considers mechanical overload features. This means the equipment is a fail-safe design, without relying on sensors and other electrical devices should the equipment be misused reaching an overload status.Example of rail-mounted SAMSON Eco Hopper in operationSEA-invest chose the SAMSON Eco Hopper for its flexibility. In addition to being able to handle a variety of different materials, the equipment can be configured at a later stage to suit evolving port operations. The lower structure of the hopper has been designed to be removable so that it can be relocated if needed at a future new terminal. NoteThis article was originally published in Dry Bulk magazine. To receive your free issue, click here.

Minimising the impact of imports

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