Water Energy installs a treatment plant for the booths’ waste water ad KFTS

KFTS, the Slovak branch of Korea Fuel-Tech Corporation, specialized in the production of plastic components for the bumpers of KIA cars, equipped its coating system with an advanced treatment system for the waste water from the booths’ overspray capture veils.

The three spray paint booths have a significant flow rate, about 10 m³/min. In order to ensure constant circulation of clean water and avoid wasting resources, the installation of a treatment plant for the booths’ waste water, specifically a flotation sludge remover, was a strategic choice.

For this part of the plant, a Skimmerflot 15000 system able to treat up to 15,000 l/h was installed.

“KFTS’ three spray paint booths produce an overspray of about 30 kg of paint per day. Skimmerflot performs a chemicalmechanical process”, explains Lorenzo Dal Passo, manager at Water Energy Central Europe, Water Energy’s Polish branch. “The coating is subjected to flotation and then separated from water in the sludge remover. Technically, through flotation the denatured paint is aggregated in flakes floating on the water level, thus enabling the sludge to be removed without any sedimentation in the booth’s tank. Once the water has been drawn from the collection hole, we inject a flocculant able to aggregate the coating particles in a pre-set contact time and make them float on water. In the recirculation circuit, we dose a coagulant able to separate the paint from water. The latter returns to the booths’ overspray capture veils, while the mechanically separated coating is collected in big bags to be disposed of.”

“For the purposes of the sludge removal process, the control of the pH value is crucial, since it must be kept constantly neutral to ensure good flocculation efficiency”, adds Dal Passo. “The machine is fully automatic. Level sensors control the recirculation and mixing of the chemicals based on the process parameters, and the operator intervenes only in the event of a problem. Finally, we installed a softener in the booths’ water-cooling system to prevent any limestone formations in the circuit.”

“Thanks to this flotation waste water treatment system, we have reduced the costs for the booths’ maintenance and the cleaning of pumps, water veils and abatement systems,” explains Marián Čerňanský, Paint Line Deputy Manager of KFTS. “Sludge no longer soils the water veils, the pumps, the back of the booths and all the parts in contact with it. The sludge residues are also directly put into big bags and ready for disposal, with a humidity of less than 40%. In general, the Skimmerflot system ensures an 80% sludge recovery efficiency; we expect to have to replace the booths’ water only once a year.”

Read the full article on ipcm® International Paint&Coating Magazine n. 46.