Salzgitter sewage treatment plant

The construction project for the Salzgitter-Nord sewage treatment plant in close proximity to the A39, had the aim of making the conveying and intermediate storage of the de-watered sludge more flexible in order to minimise the risk of disposal bottlenecks. Management should be fully automated in the future. The existing discharge system and the option of storage in 10 cbm containers should only be maintained and connected as an emergency solution. To convey the de-watered sludge into the new container, they decided on a closed worm conveyor. Due to the structural circumstances, the piling silo needed to be designed to be accessible from below. The contract for the realisation was awarded to HUNING and was subject to strict conditions as it had to be guaranteed that the de-watering operation could continue to operate as much as possible without any problems during the conversion measures. The conveying technology was therefore dismantled and reconnected within a narrow time frame. The use of a mobile de-watering system for the bridging was not intended.

The sludge is conveyed into the silo from two centrifuges via a worm conveyor route.

The stack silo, which can be accessed from below, has a filling capacity of approx. 130 cbm with a diameter of Ø 4m and a cylinder height of approx. 7m. The total height including the steel base is 18m. A steel staircase leads to an intermediate platform at the height of the silo floor. The following climb to the roof is via a ladder. Discharge takes place using an hydraulically actuated sliding frame in a worm trough conveyor with central discharge. The discharge is sealed by a hydraulic slider. To protect against frost, the silo floor and cylinder are designed with a frost protection device and insulation. Due to the versatile usage options, high precision and reliability, a weighbridge was chosen for the weighing which was embedded in the lane beneath the silo.