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OKI aerator mixerThe submersible OKI aerator mixer is a heavy-duty, non-clogging, gentle mixing unit which can operate both as an aerator and as a mixer.
Aerator mixer upgrades industrial wastewater treatment
Sulzer submersible aerator mixer improves wastewater treatment in a cardboard mill
Europac is a paper, cardboard, and packaging company with mills in Spain, France, and Portugal. The French site near Rouen specializes in corrugated cardboard and has a production of more than 300’000 tons per year. In the cardboard production process, Sulzer pumps and agitators are widely used. The mill has its own biological wastewater treatment plant with a total capacity of 350’000 population equivalent. Once treated, the water is recycled in the mill or restored to the natural environment. The WWTP has been modernized regularly during the past years.
The challenge
The effluents from the paper mill contain a high amount of organic matter. In the wastewater treatment plant, the effluents go through an anaerobic tower reactor prior to being aerobically treated in an activated sludge process. The aeration of the wastewater is done in successive basins - first in a circular tank with external bottom jet aerators and then in a rectangular lagoon with surface aerators. With the increase of the WWTP capacity, the oxygenation of both basins, especially the first one, had become insufficient. Therefore, Europac decided to upgrade the aeration performance of the existing installation with minimum capital expenditure in 2014.
The solution
Sulzer, together with the local contractor Eco-Tech, came up with the solution to add an aerator mixer OKI 2000 in the middle of the circular tank. The OKI is fed by compressed air distributed through a flexible hose. Despite the high tank depth, no air cooling is needed. The OKI runs in parallel with the five bottom jet aerators, and the total oxygen transfer rate is now more than tripled. Thanks to its efficient mixing capacity, the OKI eliminates all types of sedimentation that used to occur in the middle of the tank earlier.The OKI aerator mixer is a problem solver and it has helped us improve the overall efficiency of the wastewater treatment plant.
Joel Bruwaert
Technical and Projects Director Europac
Customer benefit
For the aeration and mixing of harsh industrial wastewaters, the OKIs have a justified reputation of steady performance, robustness, and reliability. These features have been confirmed at the Europac WWTP. After an easy installation, the OKI 2000 E-37AM has been running smoothly with no degradation of the aeration effciency with time. In addition, the machine is liftable for quick and practical maintenance without emptying the tank.
Product specification
OKI 2000 E-37AM
- One OKI 2000 E-37 AM with air hose, lifting cable, and electrical cables
- The OKI is installed at the bottom and in the middle of a circular tank (diameter 19 meters, depth 9 meters).
| Power | 37 kW |
| Protection type | IP68 |
| Voltage | 500 V / 50 Hz |
| Temperature control | Thermal switch 130°C |
| OKI dimensions (diameter x height) | 2'252 mm x 2'195 mm |
| Unit weight | 2'070 kg |
| SOTR | 276 kg O₂/h |
| Air lowrate | 3'005 Nm3/h |