erzo ARA, Klärschlammtrocknung Oftringen - Krananlage Bunker

As part of the project “Replacement Facility for Sewage Sludge Treatment”, the existing sewage sludge incineration plant located on the premises of the waste‑to‑energy facility (KVA) will be replaced by a new drying installation. This installation is designed to dry 34,000 tonnes of sewage sludge per year, increasing the dry solids content from an average of 28.5% to approximately 90% TS.

The sewage sludge consists of sludge produced at the ARA itself as well as sludge delivered from other wastewater treatment plants (ARAs) in Switzerland, with an average density of 1.2 t/m³.

The installation consists of several components: a sludge reception hall, a logistics system with bunker, crane and conveying equipment, dryers with exhaust‑air treatment, and a dried‑sludge storage area including a loading station for onward transport.

Dewatered sewage sludge is delivered by truck to the reception hall and tipped into the reception bunker. From there, it is transported by a crane system either into the storage bunker or directly into the sludge feed unit. From the sludge feed unit, the dewatered sludge is pumped via a pumping system into the feed chamber of the drying installation. The dryers dry the sewage sludge, and the exhaust air generated during the drying process is routed through an exhaust‑air cleaning system. The dried sewage sludge (referred to as dried product) is conveyed via hydraulic conveying systems into the dried‑sludge silos. Beneath the dried‑sludge silos is the loading station for removal of the dried product. The dried product is used as an alternative fuel in the cement industry.

The crane system, consisting of two redundant sludge‑grab bridge cranes and their fully automated control system, is part of this tender. The power supply up to the interface located at the centre of the crane runway will be provided by the client. The active crane must achieve a conveying capacity of 32 m³/h from the reception bunker.

The erzo ARA site already hosts a wastewater treatment plant (ARA) and a waste‑to‑energy plant (KVA). The KVA will be replaced by a new facility in the near future. The resulting logistics flows must be taken into account in the project.