6 minute read
What’s In Your Sandwich?
Amy Duncan, Dos Santos International, USA, details a recent installation of a high-angle conveyor at a port to easily move materials for export.
Created by Dos Santos International (DSI), the Sandwich Belt high-angle conveyor can take on many forms and provide numerous advantages. This technology can offer a clean, environmentally sound operation because the high angles of 90˚ are typical, and lifts of 300 m are easily accomplished.With all the positive features of the DSI Sandwich Belt conveyor, it has been successfully used in mining, quarries, material being carried remains hugged between the two conveyor belts. The DSI Sandwich Belt high-angle conveyor has been designed to achieve higher conveying speeds and greater capacities than other high-angle conveying methods; plants, and tunnelling, as well as one sector which is less talked about: ports and terminals. The DSI Sandwich Belt high-angle conveyor has not only been implemented on shiploaders, but the company's ingenuity took the technology
Figure 1. The DSI mobile Sandwich Belt shiploader is driven from the dock when not in use, stored, and parked much like parking a car.
Figure 2. Materials are loaded at the mouth of the Sandwich Belt high-angle conveyor by a mobile feeder.
Figure 3. Adder Snake generalised Sandwich entrance.
Figure 4. Adder Snake generalised layout. beyond perceived limits to offer effi cient and sustainable solutions to solve challenges at ports and terminals.
Mobile shiploader
Australia’s fi rst DSI Sandwich Belt high-angle conveyor shiploader elevates 1000 tph of a variety of materials – from high-value ores to grains and woodchips – from trucks to ship. Conventional conveyors would not have fi t the limited dock space, thus a smaller footprint was required. Recognised for the ability and advantage to elevate at much higher angles, the DSI Sandwich Belt conveyor was engineered to elevate materials at a 50˚ angle.
Additionally, because of the limited dock space, it was ideal to have a system that was mobile and could be removed from the dock when not loading ships (Figure 1). The ingenuity of DSI partner, Cortex Resources of Victoria, Australia, produced this drivable and completely mobile shiploader.
One of the more noted features of the DSI mobile Sandwich Belt shiploader is how it is driven; a dream come true for the child in all of us, this system is driven by remote control. The operator straps the remote control to their body and proceeds to drive the shiploader slowly and carefully to the dock, while standing or walking along the dock. The shiploader is carried on a tripod of rubber tyre assemblies, with each assembly mounted on a vertical axis that can be rotated. The rear tyre assembly consists of four rubber tyres that steer and drive the shiploader. The two forward tyre assemblies each consist of two non-driven tyres.
Thus, without repositioning the DSI mobile Sandwich Belt shiploader, with the forward tyres set parallel to the longitudinal axis, it can travel forward and back and be steered in either direction. With the tail tyres fi xed, the front tyres can be oriented and travelled for a slewing motion. With the forward tyres set perpendicular to the longitudinal axis, it can be moved side to side while oriented in its loading position over the ship.
Materials for export are trucked to the dock and dumped onto a special mobile feeder. The bulk is fed continuously and uniformly into the mobile Sandwich Belt’s receiving chute.
The DSI mobile Sandwich Belt shiploader elevates the bulk over the ship’s deck to the hatch, where it is discharged into the ship’s hold. At the Sandwich Belt conveyor’s discharge, a special telescoping chute with a rotating pivot spoon facilitates even and complete fi lling of the holds.
The Port of Adelaide is the main port in South Australia, it works with a range of outbound mining cargoes including: limestone; metals and scrap metal; iron ore; iron and steel; mineral sands; mineral concentrates; cement and cement clinker. It also transfers materials such as grains and woodchips.
A design to fi t the project
The mobile shiploader set the stage for DSI to supply its Sandwich Belt highangle conveyor at the Yara Sluiskil shiploader upgrade in the Netherlands.
The initial design concept for the upgrade used a conventional conveyor stinger boom out from the perpendicular
dock conveyor, to the tail of a standard DSI high-angle conveyor. This had the disadvantage of an additional transfer and extra equipment, so the client readily embraced the idea of replacing the stinger conveyor with an extended high-angle conveyor tail to receive the material directly from the dock conveyor tripper. The layout of the new arrangement immediately revealed that suffi cient tripper height did not exist to accommodate the tail pulley of the Sandwich Belt high-angle conveyor.
The solution was to employ the DSI Adder Sandwich Belt high-angle design, using a lighter construction belt that could be wrapped around a smaller tail pulley. To accomplish the high-angle lift, the DSI Adder Snake swallows the narrow conventional belt, along with its material, into the two wider sandwich belts – allowing the material to enter the sandwich belts with minimal disturbance. It achieves this without the energy loss and additional equipment required for a standard transfer. The concept of the DSI Adder Snake, invented by DSI’s Vice President, Marc dos Santos, was inspired by a very different application: elevating material from under large storage domes. The use of this technology extends to a wide variety of applications, including marine terminals, stacker/ reclaimers, and long overland systems.
The Yara shiploader application provided the fi rst opportunity to implement the Adder Snake concept. The DSI Sandwich Belt high-angle conveyor transfers urea and Amidas prills at a rate of 600 tph at a 45˚ angle (Figure 5). The material will be transferred from the tripped dock conveyor onto the 1200 mm wide Adder Belt, which is then swallowed with the bulk into the 1600 mm wide Sandwich Belt. The bulk is then elevated to the shiploader boom conveyor. The sandwich conveyor discharge is centred on the rotation axis of the boom, allowing the boom to rotate freely.
Dos Santos International is a foremost authority on Sandwich Belt high-angle conveyors and was founded on its extensive worldwide experience in sales, engineering, and construction of bulk materials handling systems and equipment. This has included contributions that have expanded the range of bulk handling and transport solutions. While typically thought of as an elevating solution in mines, quarries and plants, the DSI Sandwich Belt high-angle conveyor has proven a high level of flexibility to bring costsaving solutions on both land and sea.
Figure 5. The DSI Sandwich high-angle conveyor will transfer urea and Amidas prills at a rate of 600 tph at a 45° angle.
