Slow movement – but high demands

Profile

• What was needed: E2 energy chain in a weatherproof enclosure made of stainless steel,  chainflex cables
• Requirements: Year-round availability with 24/7 operation, frost, strong solar radiation, minimal maintenance effort, as the installed system is difficult to access
• Industry: Sewage treatment plants
• Success for the customer: Energy chain solution/complete solution especially for sewage treatment plants, many years of trouble-free operation with minimal maintenance, strong price-performance ratio

For an expert in automation technology, the automated process sequence at the primary clarifier of a wastewater treatment plant has an incredibly calming effect: The movable scraper, which travels on a linear robot above the tank, takes several minutes to convey oil and grease as well as the settled sludge to the end of the tank, where it is pumped out and sent for treatment.

This application is therefore atypical for an energy chain – but the low speed of the movements should not lead to the conclusion that this is a "low end" application for moving cable guidance units. The opposite is the case. The energy supply system must function all year round and outdoors in 24/7 operation – in frost, strong sunlight, in corrosive, sometimes aggressive environments and with minimal maintenance. Furthermore, the primary clarifier of the plant in Plauen is relatively long at almost 60 metres, and the mobile energy supply system had to be assembled on the inside of the tank.

Corrosion resistance is therefore even more important here, as is maintenance-free and wear-free operation as far as possible: An energy supply system is not accessible here without draining the tank.

At the time the operator was looking for a solution, igus had fittingly just introduced a new standard for sewage treatment plant technology: The basic flizz system – a complete solution for mobile energy supply to scrapers, screens and other sewage treatment plant systems.

It consists of an E2 energy chain, which is filled with the tried-and-tested chainflex cables and guided safely and trouble-free in a weatherproof stainless steel housing. The compact and robust system is suitable for floor and wall mounting, allows travels of up to 200 metres and has been developed from the ground up for many years of trouble-free operation with minimal maintenance. It won over the operators of the Plauen wastewater treatment plant, and in the subsequent tender, which was awarded to an independent engineering firm, the price-performance ratio was also impressive, meaning that nothing stood in the way of the installation.

The filling of the energy chain depends on the operator's wishes. Cables with up to 25 cores can be used, and signals from drives and sensors can also be transmitted in addition to energy. In many sewage treatment plants – including in Plauen – a pull wire is inserted into the chain so that another cable can be pulled through if required. The ZWAV has thus found a future-proof and economical solution for supplying energy to the scraper.