Enclosed Conveyors and Transfer Points

Enclosed conveyor systems transport bulk materials (including coal, iron ore, grain, cement, and fertiliser) between ship, storage, and loading points in sealed structures that prevent dust emissions and material loss. This may include, among others, fully enclosed belt conveyors, covered ship loaders and unloaders, sealed transfer chutes and loading points, screw conveyors or pneumatic systems for fine materials, retrofitting covers to existing conveyors, and mobile enclosed conveyors for smaller ports.

For DMC ports, enclosed conveyors and transfer points can reduce dust emissions and air pollution, prevent contamination of land and waterways, minimize material loss and waste, improve worker safety and visibility, and reduce clean up requirements and runoff contamination. Enclosed systems are particularly important in ports handling fine, dusty, or hazardous bulk materials.

Enclosed conveyor systems represent a significant improvement over open belt conveyors for dusty bulk materials. Open belts allow dust to escape along the conveyor path, at transfer points, and at stacker reclaimers, contributing to ambient air pollution, material loss, and contamination of nearby surfaces and waterways. Fully enclosed conveyors use covers, galleries, or tubular designs to contain fugitive dust along the entire conveyor length and can support material fall out at transfer points.

Enclosed ship unloaders and loaders are increasingly standard for modern bulk terminals. Screw type ship unloaders, provided by manufacturers such as Bruks Siwertell, use enclosed screw conveyors to lift bulk materials from vessel holds to shore side handling systems, enclosing the material throughout the transfer (Bruks Siwertell, n.d.). Pneumatic ship unloaders, provided by manufacturers including Vigan Engineering, use a flow of air, typically under vacuum, to transport grain and other bulk materials through pipes (Vigan Engineering, n.d.; PEMA, 2022).

Transfer points between conveyor segments, loaders, reclaimers, and storage facilities are particular sources of fugitive dust when not properly enclosed. Sealed transfer chutes, enclosed transfer towers, and dust extraction at transfer points can reduce emissions substantially. DSH Systems hopper technology, for example, minimizes air in the product flow and compacts the product to reduce fugitive dust when loading open bulk carriers and barges (DSH Systems, n.d.).

Retrofitting enclosed systems to existing conveyors can be an option for ports seeking to upgrade environmental performance without full terminal redevelopment. Retrofit solutions include adding conveyor covers, enclosing transfer points, installing dust skirting and sealing systems, and adding extraction ventilation at critical transfer locations. Mobile enclosed conveyors can support temporary or smaller scale operations where fixed infrastructure is not economically justified.

In ASEAN ports, Jurong Port in Singapore moves imported cement from ship to silo through an airtight air-slide conveyor (Jurong Port, n.d.a). Major coal terminals globally, including Newcastle Coal Infrastructure Group (NCIG) in Australia, apply full or partial conveyor enclosure, wind shields and an integrated dust management system at scale (NCIG, 2023). Research published in MDPI Journal of Marine Science and Engineering has documented fine dust management and supply chain considerations at dry bulk ports (Hwang and Kim, 2020).