Water Preparation for the Painting Lines
The newly constructed KIA Motors plant in Teplička nad Váhom, Slovakia requires more than 120 cubic metre of process water per hour. The water must be supplied in high-purity quality conforming to defined quality parameters for the purpose of processing the automobile paint line. For this reason, the food water quality used is drinking quality water while all systems and components must be installed silicon free.
ProMinent desined and supplied the various systems of the water treatment plant for the consulting engineers Takenaka. The services provided included the complete solution from the planning stage through delivery and installation to commissioning.
The water treatment plant effectively fulfils all process functions between the initial and final product:
- Storage of the untreated water
- the pretreatment process stages of filtration
- dechlorination and conditioning, main treatment by reverse osmosis and distribution to the consumers.
As from June 2006, the KIA plant will produce 300,000 vehicles annually. This makes it the second largest plant of an Asian automobile manufacturer in Europe. Water-soluble paints are used in the in-plant painting lines. As scheduled, the water treatment plant necessary for this purpose will be handed over ready for use in November 2005. As the designer and provider of the water treatment plant, ProMinent is responsible for the fully automatic system. The drinking quality water is stored in steel tanks with a capacity of 300 m3. Together, two high-performance vertical pumps deliver the water at a maximum rate of 200 m3/h to the two-stage mechanical filtration systems, which remove suspendend solids down to a particle size of 5 µm.
The chlorine-based disinfectants in drinking water as well as the water hardening substances calcium and magnesium could damage the membranes of the downstream reverse osmosis units. A sodium bisulphate solution is used to remove the disinfectants. The feed of this solution is undertaken by two metering pumps. A further metering system adds the antiscalant to prevent lime scaling of the system. Both the pump station as well as the metering systems feature standby units. The fully automatic measuring and control technology effectively monitors their operation.
The three reverse osmosis trains for water demineralisation form the heart of the plant. With a permeate quality of 20 µS/cm, they achieve an extraordinarily high degree of salt rejection. A measuring and control system adjusts the correct mix ratio of permeate to pretreated water. It guarantees the required conductivity of 150 µS/cm and mineral composition in the final product. A metering system for the controlled feed of caustic soda ensures a pH value of 7 to 7.5 in the process water.
The user sets the required parameters on a touch screen, from which he can conveniently control the entire system.
At the end of the process, a distribution system transfers the treated water to the consumers. A bypass line guarantees the reliability of the supply system.
The Siemens control system Simatic S7 links all the components. Via a Profibus interface, it is effectively integrated in the higher-ranking process control system at KIA.