There are two aspects of wastewater treatment plants at Celle (Germany) which have a direct use: in addition to cleaning waste water, the sewage sludge which arises with the nutrients it contains can be used later as manure in agriculture.
Look behind the scenes
The sewage sludge is transported via a pressure pipe around 25 metres in length with several right-angled turns – ten metres of it being geodesic – to a silo and from there it is later spread over agricultural areas. So that the mix can be stored, it is first dewatered in an angle press and flocculating agents are added.
Because of the high cohesiveness which caused repeated entanglements and bridge building. "The operational downtime amounted to three to four hours a week in all," says the Area Sales Manager from NETZSCH. The wastewater treatment plant need a reliable system without shutdowns.
The pump specialists from Waldkraiburg developed the aBP module®. It comprises a top hopper with two spoked wheels attached to its internal sides. The wheels sit deep inside the hopper and are very close to the walls. When they turn, the effect on the medium being poured in is as if the whole hopper sides were moving. The pumping system with the integrated bridge breaker has also proved itself in continuous operation. Operational reliability has increased considerably, while it has been possible to almost completely do away with inspections for the conveyor, which had been standard up to this point. "The plant and the aBP module have proved to be very robust," reports the expert from NETZSCH. "Since then there have been no more operational shutdowns."
NETZSCH: NEMO® Progressing Cavity Pumps BF
with aBP bridge breaker
Medium: Sewage sludge
Throughput volume: 2 up to 5 m³/h
Rotations speed: Under 30 rpm
Pressure: 12 up to 15 bar
Dry matter contents: 25-35%
Viscosity: between 10 and 22 Pas