At Rabas Protec in Saint Nazaire, France, aluminium parts are produced, mainly for the aerospace industry. After mechanical processing, the parts are anodised and painted to protect them from corrosion. To do this, the surfaces of the parts are first prepared in degreasing baths, followed by sodium and acid pickling.
Before the surface treatment, an NDT test can be carried out using dye penetrant testing. The final step is painting. The group specialises in machining, surface treatment and painting of aluminium parts.
When parts are cleaned, rinsing water from the anodising process and the dye penetrant test accumulates. Until now, this water was treated by an aging vacuum evaporator with a theoretical treatment capacity of 15 cubic metres per day. Due to the growing production, this capacity was no longer sufficient - therefore, investments were to be made in a more modern system. An important criterion was the quality of the treated water to be able to reuse it in the surface treatment sinks.
Vacuum distillation has established itself as the most economical solution for treating a wide variety of industrial wastewater. Especially when a high treatment quality is required, these systems offer an advantage over membrane systems or chemical-physical treatment methods, which leave a high level of residual contamination in the treated water.
This is not the case with the energy-saving evaporation of wastewater under vacuum: the rising water vapour is free of contamination and can be reused - condensed as a clean distillate - in production processes. The decision in favour of H2O and its VACUDEST was made primarily because of the high distillate quality, which had previously been confirmed in H2O's own laboratory in the application centre for wastewater-free production.
