Water flows in a closed cycle at plant!

In its electronics manufacturing plant in Amberg (EWA), Siemens has commissioned the first washing center for cleaning SMD (Surface Mounted Device) tools to operate entirely without the generation of wastewater. For each cleaning cycle, 1,800 liters of rinsing water are regenerated. After around ten uses, the water is evaporated using a special method and subsequently returned to the cleaning process. The system has also succeeded in driving down operating costs by 40 percent.

The Siemens EWA plant processes around three billion components from 200 suppliers every year. Over a total of 18 SMD lines, regular maintenance and cleaning operations include the regeneration of condensate filters from the reflow ovens and cleaning over 70 used stencils every day. Previously, the purified process water was discharged into the sewage network. By installing a new electronic washing system, the aim was to not only significantly increase overall cleaning capacity but also to achieve savings in terms of costs and fresh water consumption. The solution supplied by Kolb Cleaning Technology GmbH permitted wastewater emissions to be reduced to zero.

A schematic view of the new washing room at Siemens in Amberg: On the right the three fully

automatic Kolb AF 60 cleaning systems, next to them on the left the (blue) storage tanks for

the cleaning fluid. Further to the left are the (light colored) storage tanks for the rinsing water

and in the foreground is the (blue) Vacudest evaporator.

Using the AirFlow process developed by Kolb, the used tools are placed in a cleaning chamber and submerged under pressure into cleaning fluid, which is subsequently filtered. After around ten washing cycles, the cleaning fluid is guided into an evaporation system for treatment. The system centers around the Vacudest wastewater evaporator supplied by H2O GmbH, a German company based in Steinen. The evaporator uses the principle of material separation due to boiling point differences. Heavy metals, salts, oils and greases remain in the evaporation residue. The evaporated water from the cleaning fluid is fed back to the cleaning circuit in the form of condensed fresh water – to be used for another ten washing cycles. The plant now works in continuous mode without producing any wastewater whatsoever, and has also allowed operating costs to be reduced by 40 percent. «