Safe bulk material conveyance with energy chains and sensors in bucket wheel equipment

Talwandi Sabo Power Limited (TSPL) is a coal-fired power plant in Banawala, India. Stacker reclaimers are used here in bulk handling for mining and loading coal, with the coal-fired power plant being used directly with the coal to generate energy. As it is central to the continuous operation of the coal-fired power plant, it cannot afford to break down.
Stacker reclaimers are a combination of two different machines, with the stacker transporting the coal to a stockpile and the reclaimer sending it to the power plant's boiler as required.
In order to be able to move flexibly to different positions during mining, the entire stacker reclaimer constantly travels on a huge 700 metre long rail track. Up to now, a cable drum (cable reeling drum; CRD) has always been used for the mobile cable routing of the machinery and thus the power supply. As the power supply is made up of various individual components such as the motor, gearbox, switch, slip ring or bearing, repeated maintenance measures were essential for the operator. The exposed high-voltage cable (11 kV), whose outer jacket could be damaged by the coal transported in the system, also required a great deal of attention. During the 3-year period of use, the cable diameters were therefore increased, which led to increased weight and increased sagging of the cables. This put a strain on the cable drum drive, which ran unreliably and led to tension problems in the cable. The sometimes severe damage to the cables led to unreliable operation of the system and high maintenance costs.

Due to the repeated problems and increased downtime of the entire system, the operator began to investigate a suitable solution. In spring 2019, a project to overhaul the cable routing system was finally launched between the operator and an igus® project team. Close contact over several months covered the entire process from project design to the final installation of the new cable routing. The core of the new solution is a huge energy chain with a travel of 670 metres. This is the second plastic energy chain in the world with this length of travel.
As such a superlative solution can of course also entail uncertainties, the proposed chain - an E4/4 roller energy chain of type 5050RHD - was extensively tested in advance in our in-house laboratory in the form of a sample.
The cables are safely guided inside the chain and are better protected from external influences. Our chainflex® cable, designed for moving applications and developed in conjunction with our energy chain, was also used in the new cable routing. In order to provide additional planning security for these dimensions, the entire cable routing is supplemented by smart plastic, i.e. intelligent sensor technology in combination with energy chain.
So-called iSense modules ensure continuous condition monitoring by using sensors along the chain to measure the prevailing tensile and shear forces. This data is analysed by a module in the control cabinet and can trigger actions such as switching off the system if a limit value is exceeded. Damage to the cable routing can thus be prevented before it occurs.
Overall, the interaction between the energy chain, cable and sensor technology has resulted in a solution that has made a huge leap forward in terms of system availability, durability and safety during operation. The plastic-energy chain saves weight, simplifies cable routing and saves the operator high maintenance effort and costs.