This project involved the installation of a GEA centrifuge.
The centrifuge is fed via a new sludge pump station and polymer dosing system. A new polymer batching and storage plant was sized and built to meet site wide requirements The dewatered sludge collection was improved by providing a greater trailer capacity and user-friendly design for transportation of sludge to the Windrow. The access for the trailer to collect the dewatered sludge from the conveyor was improved by creating a drive through rather than the current reverse park area.
All work, with the exception of EIC, was undertaken by Waternish using our own labour and plant and equipment.
- Greater Western Water
- Project Completion
- October 2019 to February 2022
A single centrifuge, will dewater the anaerobically digested sludge. The centrifuge will be installed in the existing dewatering building and operate in duty/ standby configuration with the existing belt filter press (BFP) which is to be retained in service. The BFP process train, including the existing sludge feed pump, liquid polymer dosing system, and dewatered sludge conveyor, will remain unchanged.
An existing sludge mixing tank provides a homogeneous feed to the dewatering facility. The tank and mixing system shall be retained in service. Homogeneous sludge from the sludge mixing tank shall be pumped to the centrifuge via new duty/standby progressive cavity type sludge feed pumps.
Dewatered sludge will be conveyed from the centrifuge by a new automatic conveyor system to one of two cake trailers located on a new sludge collection hardstand to the east of the dewatering building. When full, the cake trailers will be transferred, by others, to adjacent land for further drying in windrows prior to beneficial reuse.
There will be no odour control or treatment provided for the new dewatering train at this point in time.
A new polymer system, utilising powder polymer, shall be provided to aid dewatering of anaerobically digested sludge. Polymer shall be dosed at predefined point(s) prior to the centrifuge, by adjustable speed progressive cavity polymer feed pumps. Polymer will be dosed at 0.02% to 0.05% concentration at the centrifuge. The Polymer make-up and batch tanks, dosing panel and associated control panel may be located within the existing polymer dosing room within the dewatering building, if suitable. The powder polymer storage silo and transfer system shall be located externally to the dewatering building.