AHA Hannover – Energy through Fermentation of biological waste
May 24, 22
AHA Hannover is operating its organic waste treatment plant since the year 2005.
The organic waste treatment plant was planned and supplied by the company Valorga international (today Urbaser). Task of this plant is to ferment organic waste in order to reduce the volume and gain energy. For this purpose, residual waste from the households and commercial waste of the Hanover region, as well as separately collected waste is mechanically processed. After processing the waste, it is fed into the fermentation process. The annual throughput in this plant is about 100,000 t.
Feeding pump KOS 2180 for entry into the fermenter
The components delivered by Putzmeister are in operation in two areas of the plant:
- Loading area
- Recirculation area Two lines were drawn for each area Installed.
The fermentation tank is fed via the Putzmeister mixing and conveying system, consisting of:
- Storage hopper
- THS mixing and precompression screw
- and KOS piston pump
The mechanically processed organic waste is added to the Putzmeister mixing and conveying system. The biowaste is fed into the storage tank via a conveyor belt, which is located above the mixing screw. At the same time, recirculation material is pumped via a pipeline from the Fermentation tanks into the storage hopper. The dosing is done by a KOS 1070 piston pump (recirculation pump).
Both media and the dilution water are fed into the storage hopper. At the same time, steam is fed into the pre-compression zone of the screw and mixed with the other components. The mixture is fed to the feed pump KOS 2180 by means of the mixing screw and then pumped to the fermentation tanks.
Recirculation pump KOS 1070
Plant concept
The system is designed and constructed for the following data:
Conveying medium (mixing screw, feed pump)
| Material | organic waste and ferments |
|---|---|
| DS-Content of mixture | 25 – 35 % |
| Temperature of mixture | 40 – 50°C |
| Specific weight (mixture | 0.9 – 1.1 t/m |
| pH-value | 6-8 |
| size of foreign bodies | < 60 mm |
Environmental conditions
| Temperature | 5° to 40°C (inside building) |
| Rel. humidity | 0 – 90% on annual average |
| Earthquake factor | 0g (horizontal |
Delivery rate / delivery pressure
| Feed pump | 80 m³/h at 10 bar |
| Recirculation pump | 27 m³/h at 5 bar |
Operational data
| Feed pump | 11 h/d, 250 d/a |
| Recirculation pump | 11 h/d, 250 d/a |
Machine components
Storage hopper
| Hopper volume | 2.0 m 3 |
| Material | INOX 1.4301 |
Mixing screw THS 3062 MX
| Screw diameter | 630 mm |
| Max. mixing power | 240 m³/h |
| Delivery rate | according to pump rate |
| Control range | 50 – 100 % (adjusted) |
| Drive of screws | hydraulic with 2 hydr. motors |
Feed pump KOS 2180
| Diameter delivery cylinder | 280 mm |
| Piston stroke | 2100 mm |
| Volume delivery cylinder | 129 l |
| Conn. to delivery pipe | DN 200, PN 16 |
| Delivery rate (eff.) | 80 m³/h |
| Delivery rate (theo.) | 100 m³/h |
| Control range | 10 – 100 % (adjusted) |
| Delivery pressure (eff.) | 10 bar |
| Stroke time normal operation | 15 sec. |
| Stroke time min. | 5 sec. |
Hydraulic power pack HA 110 E
| Electric drive motor | 110 kW and 1450 – 1/min, 50 Hz |
| Various oil pumps | KOS 2180, KOS 1070,THS 3062 MX |
Recirculation pump KOS 1070
| Diameter delivery cylinder | 230 mm |
| Piston stroke | 1000 mm |
| Volumen delivery cylinder | 41.5 l |
| Conn. to delivery pipe | DN 150/ PN 10 |
| Delivery rate (eff.) | 27 m 3 / h |
| Delivery rate (max. theo.) | 28.5 m³/h |
| Control range | 10 – 100 % |
| Delivery pressure (eff.) | 4.5 bar |
| Stroke time normal operation | 15 sec |
| Stroke time min | 5 sec. |
For more than 30 years, Putzmeister has been supplying its S-tube piston pumps both for feeding the fermenter with fresh substrate and for pumping fermentation residues. Since organic waste always contains a high proportion of impurities such as glass, ceramics, pieces of metal, etc., which cannot be completely sorted out during processing, the S-tube piston pump has proven to be the ideal machine for this application
The fermenters are fed in parallel on two lines via two KOS 2180