30. Jan 2019

Screen belt: Integrated wear indicator in Sonneberg

The Sonneberg-Heubisch sewage plant is operated by Wasserwerke Sonneberg waterworks in South Thuringia, Germany. Since 2016 the operator has been using a type 1003 screen belt with integrated wear indicator from GKD – GEBR. KUFFERATH AG. Alongside efficient dewatering, this belt type also impressed with increased planning reliability.

In addition to the Sonneberg-Heubisch sewage plant, Wasserwerke Sonneberg also operates three other sewage plants – Steinach, Schalkau, and Lauscha – as well as eight small biological plants. In all, these facilities serve an area of 400 square kilometers. The Sonneberg facility has been in operation since 2004 and was designed to deliver a disposal rate of 48,375 PE and handle a maximum wastewater volume of 393 l/s with an average of 220 l/s. Around 20% of the wastewater comes from agricultural operations and commercial discharge. To dewater the sewage sludge generated, the sewage plant uses a type 1003 GKD screen belt with integrated wear indicator. Around 160 cubic meters of sludge is dewatered per day. In the pressing area, the sludge passes through eleven rollers with belt pressure of eight bars between the upper and lower belt. Belts previously used here regularly failed to withstand the load of the enormous forces they were subjected to. Uncontrolled seam rips caused costly downtime which required a lot of manpower to rectify. The solution came in the form of the type 1003 GKD belt with PAD seam, after which there were no more belt rips at the seam. The employees in Sonneberg were therefore open to testing the improved 1003 belt type with integrated wear indicator. A yellow inner core of the 15.25 meter long and 2.50 meter wide belt shows the degree of mechanical wear. This allows damage caused by defective plant components or process-related wear to be detected early on. Conclusions can also be drawn regarding seam wear and dewatering performance. With a suitably positive result: torn belts and unplanned downtime are a thing of the past. In addition to better dewatering performance and reliable particle retention, the further improved operational reliability speaks in favor of this belt type: belt changes are plannable and there is no longer any risk of unscheduled downtime.