In operation for 10 years without failure

Plastic energy chain travels 615m in Czech lignite plant

Ten years later, this system is still robust and exciting, remaining ideal for long-term use. At Tušimice the coal is stored in a lengthy heap on the periphery of the power plant site, which could theoretically, be used to fuel the power station for a full week. To pile the coal automatically on the heap, a 'stacker' is used. To ensure that this is reliably supplied with energy, data and media over a travel distance of 615m, the ČEZ Group opted for one of our plastic energy chain systems.

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Lignite power plant The stacker piles the coal into a heap. This is supplied with energy, data and media via cables and hoses, which are safely guided by a plastic energy chain over 615m of travel.

Problem

At Tušimice the coal is stored in a long heaps on the periphery of the power plant site, which theoretically could be used to fuel the power station for a full week. To pile the coal automatically on the heap, a 'stacker' is used, which must be reliably supplied with energy, data and media. Since the stacker is only used in the event of a stop in regular coal production in the lignite power plant, the energy supply system must also always work reliably, sometimes in 24/7 continuous operation, sometimes during a one-month shutdown. The extreme weather conditions in the cold Czech winter were also a special challenge. For example, the cables of the previously used cable drum froze time and again, which could result in repeated failures and unplanned downtimes on the long travel when the system starts up. Accordingly, the customer was looking for an energy supply system that was as resilient as it was fail-safe.

Solution

The trouble-free operation of the lignite-fired power plant in Tušimice has therefore been ensured for more than 10 years by an energy chain type 5050RHD. The 'R' in the name stands for 'rollers'. By using a roller, the coefficient of friction on long travels drops dramatically when the upper run of the chain runs on the lower run. Thereby, the coefficients of friction is reduced and up to 57 percent of the required drive energy can be saved while moving the energy chain system.
In addition to the 615 metre long travel distance, two other systems are moved with our roller energy chains, whose lengths of 400m and 150m, respectively, are not exactly short either. The two systems supply the 'reclaimer', which removes the coal from the pile and transfers it to the conveyor belt that runs to the power plant.


"By using a roller in the chain links, the coefficient of friction on long travels drops dramatically. As a result, a saving of up to 57% of the drive energy required to move the energy chain system can be achieved. "
 
Frank Schlögel, Head of Engineering Projects, Sales & Marketing at igus

Energy chain of the type 5050RHD In ten years of operation here, only a few plastic crossbars have been replaced.
Energy chain of the type 5050RHD In addition to the motor, control and data cables, a water hose is routed in the energy chain of the 5050RHD series (here right in the chain), which can be heated.

chainflex cables and electronic monitoring round off the package

Some of our chainflex cables which have been specifically developed for use in energy chains are routed inside the chains. In addition to the chainflex motor and control cables, an optical fibre cable for data transmission is also used on the 615m travel. "Bus cables are out of the question for these long travels, as the signal strength would be insufficient," says Frank Schlögel. A water hose is also routed in the chain, which can be used for heating the system.
Since commissioning, electronic monitoring has been carried out on the energy chain systems in Tušimice. This measures the push/pull forces of the chains and can switch off the system if the forces become too high. This can happen when debris enters the system, for example. In recent years, we have further developed this form of "condition monitoring" and now offer our customers a wide range of optional modules for monitoring and predictive maintenance as additional protection.