The presentation of Gebrüder Lödige Maschinenbau GmbH at IFAT (Booth A2.129) focuses on the efficient and reliable conditioning of municipal and industrial sewage sludge. An ongoing project demonstrates the potential of continuous Ploughshare® mixers in mixing and texturing.
Sewage sludge treatment in one of Germany’s biggest sewage treatment plants
Every year 220,000 tonnes of sewage sludge are generated by the Bottrop sewage treatment plant and neighbouring plants of the Emschergenossenschaft and Lippeverband water boards. In order to guarantee an optimum thermal process, this sewage sludge must be conditioned prior to incineration. The focus is thereby placed on dry matter content (DM content). This means that a specific mixing ratio of moist and dried sewage sludge and a high degree of homogeneity are essential for the quality of thermal utilisation. In addition, requirements exist regarding the structure of the material: a defined fragmentation is required for an optimum thermal process.
Type KM 600 DW Ploughshare® mixer
Trials have shown that mixing and texturing in a type KM DW Ploughshare® mixer by Lödige Maschinenbau is a suitable process for the conditioning of sewage sludge. The machine is designed for continuous operation and based on the mechanically generated fluid bed introduced to industrial mixing technology by Lödige Maschinenbau that ensures good mixing performance. The specially developed shovels rotate close to the wall inside a horizontal drum, generating a fluid bed. The process enables a high level of homogeneity and consistent reproducibility. In the case of the sewage treatment plant Bottrop, two type KM 600 DW Ploughshare® mixers have been installed. Each of its mixing drums has a volume of 600 litres and is designed for a filling level of 50 percent. An automated transport process is used to continuously feed the mixers with moist and partly dried sewage sludge. Also the drying was developed with an emphasis on sustainability: the solar thermal drying system, specially built for pre-treatment, is one of the first of its kind in Europe.
