NEW TECHNOLOGY ENABLES OPERATORS TO GO ASSET-LIGHT
by Bruks Siwertell
Having the ability to respond rapidly with a high-performance unloading system that requires no infrastructure can prove to be an ideal solution for the grain industry; Peter Göransson, Sales Manager and Senior Advisor for Siwertell, explains how.
Trade routes for the world's bulk commodities, especially in the maritime sector, benefit from a concept known as just-in-time delivery. The central idea is that if bulk cargoes can be delivered in a continuous stream, the vessels that carry them can maintain economical speeds to deliver the goods on time.
Just-in-time is not as straightforward as fast delivery, and involves certain engineering and logistical challenges, but it can offer huge economic advantages in terms of efficiency savings. Ensuring this for grain deliveries is particularly testing, as the seasonal nature of many crops creates peaks and troughs in delivery schedules, therefore anything that can lessen the impact of these on the logistics chain will deliver efficiency benefits.
Smoothing material flows
The new Siwertell port-mobile unloader works well to smooth bulk material flows in port and allows operators to be responsive exactly when required. It serves the same 60,000 dwt ship size as pneumatic systems, which are widely used in grain unloading operations, but can completely strip away their various inefficiencies.
Pneumatic systems also deliver a fast unloading profile, but at a cost; a cost in terms of elevated fuel consumption and a cost in terms of material degradation. Pneumatics rely on similar technology to vacuum cleaners, but the companies who designed this technology never had to worry about the integrity or eventual quality of what they suck up; port operators, however, do.
The same forces that propel cargo so quickly through these machines smash, crush, and scrape the cargoes all the way through the process and in the grain handling industry, crushed commodities translate into a loss of profit.
Cutting your losses
The steady action of a counter-rotating mechanical screw, combined with a specially designed inlet, submerged in the cargo, means that Siwertell machines can avoid the grain degradation problems presented by high-velocity pneumatic conveying; there are no cargo avalanches; no swirling air currents close to the intake to fling the cargo across a wide area; nor are there crushing forces, as large volumes of cargo collide with the machine's internal components.
Throughout the unloading process, large volumes of cargo are delivered deliberately and continuously from the screw-type intake to the truck or belt conveyor at the other end. This minimises any cargo degradation and maintains very high levels of handling efficiency, ultimately delivering higher cargo-handling rates and volume capabilities as pneumatic systems.
Operational flexibility and efficiency are also ensured by Siwertell's screw-type vertical intake, which offers substantial advances over those of a standard pneumatic system. A Siwertell system can unload a ship's hold at various angles – from 90-degrees to +/-30 degrees – without compromising its effectiveness.
A Siwertell machine can even unload cargo from the troublesome areas of the hold, underneath hatch coamings and in corners. As well as maintaining continuous throughput, this maximises the extent of cargo that can be unloaded, further reducing waste compared with a pneumatic which can only unload in a 90-degree vertical plane.
Siwertell's port-mobile unloader navigates the quayside using a rubber-tyre gantry. In static or rail-mounted unloaders, complex fixed engineering infrastructures are often required to ensure that an unloader is able to navigate to the locations where it needs to be, but as its name suggests, the Siwertell port-mobile unloader is highly mobile. It can be deployed immediately and makes it possible for dry bulk ports to operate without any fixed infrastructure at all.
When it comes to the unloading of docked vessels, its maneuverability allows the port-mobile unloader, not the vessel, to move along the quay during unloading. For some ports, this can be an enormous advantage and potentially allows more vessels to dock at the quayside.
It is also equipped with a large-volume intermediate surge hopper, which allows discharge operations from a ship to continue even if no trucks are imminently available. An intelligent control system monitors the level of cargo in the hopper and prevents over-filling, as well as controlling the discharge rate to the hopper.
As standard, the unloader features a double-truck loading system, with the possibility to order an optional third loading system. As the loading systems are not interlinked, one, two or all three loading positions can be used independently and simultaneously, delivering the fastest truck loading operation possible.
When the port-mobile unloader has finished discharging the vessel, the system can be moved away from the quayside to clear port thoroughfares, and even stowed when not in use. The port-mobile unloader has another advantage, because of its lightweight construction it does not require any additional structural or reinforcement work on the quayside.
Cargo handling flexibility
The port-mobile unloader offers unmatched flexibility in many areas, but it also inherits benefits common to all Siwertell screw-type unloaders. One of these is the flexibility to handle many different types of cargo with a single machine, and without modification.
As such, the port-mobile unloader is not limited in the types of cargo to be handled. Unlike pneumatic systems, which are only suitable for fine grains, Siwertell machines can handle all manner of grains as well as larger soya beans and feedstuffs without damage to the cargo. Even where the finest grains are concerned, the vertical inlet submerged in the cargo and the totally-enclosed conveying line more thoroughly eliminates dust creation than any other solution on the market.
The port-mobile unloader is extremely efficient to run and uses the latest diesel engine specifications to meet the strict environmental regulations on exhaust and noise emissions.
The robust mechanical attributes of the port-mobile unloader also translate into very low maintenance costs, especially in comparison to the high-intensity demands placed on a pneumatic system's key components. This is because the continuous low-velocity motion of the counter-rotating screw places little strain on the working components.
Its consistent and steady movement, with almost no fluctuations of acceleration and deceleration, make it possible for Siwertell engineers – and importantly, the port-mobile unloader's onboard programmable logic controller (PLC) and sensors – to accurately predict when maintenance intervals are likely to be required.
A winning package
The 400t/h or 600t/h port-mobile unloader units provide consistent, high-capacity unloading throughput for vessels of up to 60,000dwt, and propose an asset-light, space-efficient operation with minimal downtime; ideal attributes for many ports.