Combining deadweight and higher payloads with shorter closing times to unload a vessel 10 percent faster

About the customer

Nemag BV (Nemag) is a manufacturer of grabs designed for handling a range of bulk materials from coal and iron ore to grain, animal feed, scrap metal, minerals and biomass. Using Simcenter™ EDEM™ software bulk material simulation software to test and optimize the new design, Nemag worked with Dr. Dingena Schott’s group at Delft University of Technology (TU Delft) to develop a new generation of grabs for iron ore that are faster and lighter.

Simcenter is part of the Siemens Xcelerator business platform of software, hardware and services.

Their challenge

Grabs are a type of equipment used for unloading dry bulk cargo vessels, grabbing dry bulk material such as iron ore or coal from the vessel and transferring it to a hopper on the quay. Developing grabs is a complicated process as is predicting the performance of a new design, which involves building physical prototypes, an expensive, time-consuming and limiting process. It is hard to understand what happens inside the grab. The interaction between the bulk material and the grab heavily influences the performance of the grab but it is difficult to predict using traditional methods. A virtual prototyping approach was therefore developed at TU Delft to model the interaction of iron ore pellets with grabs.

Our solution

TU Delft used simulation software to perform virtual testing of a grab design and predict grab performance. TU Delft developed a coupling to use Simcenter EDEM Discrete Element Method with multibody dynamics simulation software, which they used to model iron ore pellets and a crane in a virtual environment. Extensive model calibration procedures were developed that accounted for material structure interaction. With this model they were able to effectively capture both material behavior and grab behavior. The co-simulation was validated with measurements on industrial scale at Tata Steel IJmuiden in the Netherlands. The coupled simulation was then be used in the innovative design process, providing key insights into the dynamics of the grab together with the iron ore.

Results

Simulation results were used to develop new-generation grab designs. The patented nemaX grab combines lower deadweight and higher payloads with shorter closing times, leading to great improvement in efficiency with a vessel that unloads in 10 percent less time. The new grab has been extensively tested, and its performance matches the simulation predictions.

“As an early adopter, we believed in Simcenter EDEM to help make a difference in simulation-supported design and realize breakthroughs through advanced simulations,” says Scott, associate professor of material equipment Interaction for logistics at Delft University of Technology. “We also use Simcenter EDEM in education; its ease of access comes with good support and quick response times.”

The innovative nemaX grab won two awards: the International Bulk Journal’s Innovative Technology Award in 2017 and the Red Dot Award for product design in 2018.

Teams from Nemag and TU Delft collaborated to develop a new generation of grabs for iron ore that are faster and lighter.