Die-casting production at SEW USOCOME: "We are equipped for the future and now we are also completely wastewater-free".

The solution

H2O GmbH in Steinen, a leading manufacturer of vacuum distillation systems, took a closer look at SEW's requirements and developed a tailor-made solution. As a result, the two wastewater streams from the die-casting and the cooling lubricants can now be combined, processed together and reused in the production process. SEW USOCOME's production is now completely wastewater-free.

Why did SEW USOCOME decide in favor of this solution?

Vacuum evaporators operate on the simple principle of separating substances based on their different boiling points. Industrial wastewater is evaporated under vacuum in an energy-efficient process. All substances with boiling points higher than water remain in the sump of the machine as evaporation residue and in the case of SEW USOCOME contain release agents and heavy metal salts from the die-casting. The amount of residue varies between 0.5 and 5 percent of the original wastewater volume and can be disposed of at minimal cost. The generated steam is virtually free of impurities, making the distillate an ideal resource for the generation of new process water.

1. High treatment quality
   The applied H2O GmbH technologies are unique on the market, enable a particularly high treatment quality and therefore wastewater-free production even in demanding processes. Wastewater from aluminium die-casting often has a pH value below 7 and can be corrosive. To prevent damage to the evaporator, the foundry wastewater must first be neutralized in conventional evaporators. The Destcontrol technology of H2O GmbH measures the pH value in the distillate and continuously doses lye directly into the evaporator to adjust the pH value. Therefore, a neutralization stage before the evaporator is no longer needed in many cases.
   Furthermore, in conventional evaporators the distillate is often so heavily contaminated with floating oils that it cannot be returned into the production process; it still has to be post-treated via adsorbers, activated carbon filters or membrane systems. To avoid this resource consuming post-treatment, H2O GmbH has developed the Clearcat condensation stage as an innovative novelty. The patented technology, which is integrated into the evaporator, ensures that the distillate appears clear and is almost oil-free. COD levels are reduced by up to 97 %, making the treated water well-suited for reuse.  the Clearcat module eliminates an additional treatment step in the overall process.
2. Space-saving solution
   The H2O GmbH system requires no additional treatment steps due to the integrated technologies mentioned above. There is no need for continuous neutralization or post-treatment, e.g., with activated carbon. This saves space and reduces infrastructure costs significantly.
3. Satisfaction with the service.
   SEW USOCOME appreciated the quality of H2O service even before buying the first VACUDEST. "When we were faced with far too long delivery times for spare parts from the current manufacturer of our old vacuum distillation plant two years ago, we turned to H2O," says Bernard Hen, maintenance manager at SEW USOCUME in Forbach. "... And they were there to help us. So, we already knew H2O's service very well. That is also one of the reasons why we chose this company." 

H2O GmbH was involved in the planning for the plant expansion from the very beginning. In cooperation with the architect, H2O was able to meet all of SEW USOCOME's conditions, including the implementation of a space-saving layout. The wastewater treatment is now located in a separate room. Due to the size of the production line, large storage volumes for wastewater, distillate and concentrate had to be implemented; in total, tanks with a volume of 190 cubic meters were installed.

Furthermore, H2O GmbH installed an additional control system. It integrates all the tanks visually and controls the entire system from a single point. In this way, the two new VACUDEST vacuum distillation units can also be switched on and off centrally. This gives the customer extra flexibility. "In this way, when there is little wastewater, I can simply switch off one of the two plants and determine which feed tank is going to be treated. This is particularly useful now in the transition phase, where we have not yet ramped up to full production load due to the multi-stage plant expansion, which will continue until 2032," explains Thomas Lagrange, project manager at SEW USOCUME.

Conclusion

SEW-EURODRIVE is highly enthusiastic about H2O's commitment and is looking forward to the expansion of production: "The H2O team works very precisely and reliably. They provided us with professional support from planning to commissioning. Everything that was promised was delivered. We are proud to be able to produce completely without wastewater now and also for the future," says Grégory Paralovo, maintenance preparer and energy officer.