Energy chain system e-loop in bucket wheel excavator

Holcim (Deutschland) GmbH uses a bucket wheel excavator in Lägerdorf (Schleswig-Holstein) to mine chalk as a raw material for cement production. The excavator works together with a spreader. Both devices are connected by several single cores with high cross sections. Holcim and igus have installed the new e-loop energy supply system to protect and guide the cables safely. The e-loop was developed for tough and heavy duty applications. It combines the advantages of a polymer energy chain with those of a high-strength pull rope. Inside the e-loop energy chain, the pull rope transfers the pull force to the mounting brackets and the structure. As a result, the cables are kept completely free of strain. The modular e-loop made of high-performance polymer always enables a defined bend radius and easily copes with vibrations and impacts. The system was installed around the existing cable harness in a joint project. Instead of the planned 8 hours installation time, the work was completed after only 4 hours.

Profile

Plants: Bucket wheel excavator for chalk
Industry: Cement factory
Customer requirements:

Suitable for heavy duty applications
Fast assembly
Robust

Solution from igus: e-loop energy chain system

Contact an igus® expert now

Problem

In the open-cast mine of Lägerdorf near Itzehoe, the Holcim Group operates a chalk pit. This is where the raw material for the neighboring cement plant is mined on a large scale. A bucket wheel excavator can mine up to 4,500 tons of porous calcite per day in the pit. He loads the material onto the first of several belt wagons, which transfer the chalk to a conveyor line about two and a half kilometers long. This conveys the slurry chalk to the cement plant.

As is customary in open-cast mining, the excavator is electrically driven. Two cables for the power supply, which are more than arm's thickness, must be routed just as safely as a control cable. The path of the cables leads from the stationary conveyor line via the belt wagons to the excavator. Since the excavator moves during work, the cables must also be able to move flexibly. Previously, the important lines for the bucket wheel excavator were in a hanging position. However, it also happens that they are dragged across the floor and placed there. The problem with this is that while they quickly wear out during mining due to contact with rock and uneven terrain, they freeze to the ground in frost. This situation prompted Holcim's plant engineering to look for solutions for an "orderly" and protected energy supply for the bucket wheel excavator, which proved to be not so easy.

Learn more about e-loop

Solution

Obvious solutions such as a cable drum were out of the question as cable routing, as both the stacker and the excavator move. Any additional weight, for example on the stacker arm, can cause instability. The solution: a heavy-duty energy chain that was still being extensively tested in our test laboratory at that time

The e-loop combines the advantages of a plastic energy chain with those of a high-strength and dimensionally stable traction rope. Internal tensile forces are absorbed by the traction rope and transmitted to the structure. In this way, all cables are relieved of strain and protected. In addition, the modular e-loop made of high-performance plastic ensures a defined minimum bending radius of the cables it protects. The plastic is wear-resistant and in addition, each element is provided with a "cushion" made of softer plastic. This increases resistance to shocks and blows. And because the chain is modular, additional chain links can be added or removed quickly.

After we were able to see the situation on site, we determined the diameter and required length of the e-loop. The energy chain, which is 13.50 meters long in total, was to be installed in eight hours. It was installed after just five hours. This allowed the bucket wheel excavator to quickly resume chalk extraction. Since its installation in May 2020, the e-loop has proven itself without any problems (as of 2022), according to Dieter Reitz from Holcim.
And Holcim is already planning the follow-up project: The system is now installed at the most movable transfer point, between the belt wagon and the bucket wheel excavator. It is planned to install e-loops between the belt carriages as well.

Contact a Cable Carriers Expert

Whether you're interested in end-to-end, fully assembled solutions or looking to build your own customizable project, let us assist you with a solution based on your specific application and requirements. Contact us via the form below or call us at (800) 521-2747 to discuss your project today!

Contact an Expert