30. Apr 2021

More efficient sewage sludge drying with GKD process belt

TEAtherm GmbH, founded in 2013 by five companies, operates a combined heat and power station (CHP) run on biomass with thermal sewage sludge recycling in Dinkelsbühl, Bavaria. The 5099 PPS GKD process belt used in the sewage sludge dryer is a big contributor to the high efficiency of the system.

The TEAtherm biomass CHP supplies around one third of households in the district with 64,000 megawatt hours of green energy. The biggest consumer is a state-of-the-art plant nursery next to the power station. It uses the heat generated as a by-product of electricity generation to heat a ten-hectare greenhouse. A further portion of the heat is used in the biomass CHP’s own belt dryer for drying municipal sewage sludge from around 40 different sewage plants. The belt dryer made by Andritz used here has a drying capacity of 22,000 tons of wet sludge per year and annual dry material production of 4,800 tons. Around 2.7 tons of wet sludge is dried per hour so that the water content drops from 78 to less than ten percent. The 5099 PPS GKD process belt is the key contributor to this increased drying efficiency, at around 36 meters in length, 3.80 meters in width, and with L-seam and edge coating. Unlike with polyester belts, the material of this belt type means that no hydrolysis occurs. The mesh design comprised of robust monofilaments permanently withstands the large surface weights. With air permeability of 4,300 l/m²/s optimally tailored to the drying process and a CFM value of 660, it ensures an efficient drying process despite the very closed surface. Woven in 3/2 twilled weave, it reduces dust ingression through the smaller number of direct apertures. What is more, the flatness of the underside of the belt makes it particularly resistant to wear.

The first time TEAtherm had to replace such a belt was after seven years of continuous use. As the TEAtherm team had no experience at all in fitting the belt, a special service from GKD was required. A GKD fitter traveled to Dinkelsbühl and spent two days on site. He not only fitted the belt but also trained the team in all aspects of belt fitting. For TEAtherm CEO, Jakob Friedrich, this service was another reason for his thoroughly positive opinion: “GKD impressed with fast delivery, a reliable belt, and a service we can rely on.”