Okanagan BC Municipal WWTP: Skid-Mounted Centrifuge Case Study
A skid-mounted HAUS DDE 2342 dewatering system lets a municipal wastewater treatment plant in the Okanagan, BC dewater its biosolids on site.
The application
A regional district operates this municipal wastewater treatment plant in the Okanagan, BC. Until the upgrade, the plant shipped its biosolids as a liquid slurry to a larger municipal plant nearby for dewatering.
The owner bought a dewatering centrifuge ahead of the main construction contract so that dewatered cake could go straight to the regional composting facility, cutting the hauling. The feed is a blend of fermented primary sludge, gravity-thickened with no grit removal upstream, and waste activated sludge thickened in a DAF unit.
For the solids-processing upgrade, Archer then packaged the centrifuge with its feed pumps, polymer make-down, flowmeters and centrate handling as one pre-piped, pre-wired skid system. A dry polymer upgrade followed in 2023.
What Archer supplied
- One HAUS DDE 2342 decanter centrifuge: duplex 2205 stainless bowl, tungsten carbide scroll protection, 304 stainless wetted parts, 7.5 kW main drive and 4 kW back-drive
- Local control panel with Schneider Modicon M340 PLC and VFDs, a stainless NEMA 4X operator panel with touch screen, and a remote-access router for diagnostics
- Skid-mounted plug-and-play package: centrifuge pedestal, SYDEX progressive cavity sludge feed pumps and a SYDEX polymer feed pump
- Kozegho CL-D 600 polymer make-down unit with a 600 L two-compartment HDPE tank
- Endress+Hauser Promag W 400 electromagnetic flowmeters for sludge and polymer
- Centrate holding tank with level control and transfer pump, electric sludge diverter gate, bearing RTDs and vibration transmitter
- Dry polymer upgrade (2023): bag hopper with vacuum conveyor, heated screw feeder and eductor for two-stage polymer wetting
- Commissioning, operator training and ongoing spare parts
Design basis
| Feed | Fermented primary sludge and DAF-thickened WAS, 25:75 to 34:66 by weight |
|---|---|
| Solids feed rate | 102 kg/h |
| Sludge flow | 2.29 m³/h maximum (plus 0.49 m³/h dilute polymer) |
| Operating period | 8 h/day, 5 days/week |
| Solids capture | 95 % minimum |
| Cake | 20 % solids minimum |
| Polymer | 12 kg/t DS maximum |
Design conditions from the owner’s request for proposals (2019).
Related
- Decanter Centrifuges: hAUS decanters for sludge dewatering and process separation.
- Skid Systems: pre-piped, pre-wired process skids.
- Polymer Systems: dry and emulsion polymer make-down.
- Municipal Water and Wastewater: equipment for municipal treatment plants.
- Sludge Dewatering: centrifuges, screw presses and polymer for biosolids.
- All case studies: more Archer projects in the field.