Home > Technology Process > Waste Water Reclamation

Pure Water Preparation and Recycling Process for Automobile Coating Lines

The electrophoretic coating, degreasing, and water rinsing processes in automobile coating workshops are highly sensitive to water quality. Elevated calcium and magnesium ion concentrations can lead to coating defects such as craters and particles. Pure water quality directly determines coating quality and anti-corrosion performance.
Typically, the system includes both pure water preparation and a partial wastewater recycling process.
Fresh water first undergoes multi-media filtration and activated carbon adsorption to remove suspended solids and residual chlorine, then passes through a softener to exchange and remove calcium and magnesium, after which it enters a reverse osmosis membrane unit. The reverse osmosis system operates at a high recovery rate. Its permeate conductivity remains stably below 10 μS/cm.
To meet the stringent requirements of electrophoretic paint bath preparation and final rinsing, the RO permeate further passes through a cation-anion-mixed bed or EDI system, thereby producing pure water with a resistivity greater than 5 MΩ·cm. This high-purity water has an extremely low salt content, which can prevent ionic contamination of the electrophoretic paint bath.
The pure water is distributed to various points of use through stainless steel piping. The pre-treatment rinsing tanks adopt a counter-current cleaning method, with the final stage using pure water spray rinsing.
Meanwhile, to reduce specific water consumption, coating workshops are often equipped with a reclaimed water reuse system. Spent tank solutions and wastewater, after equalization, undergo demulsification, coagulation, and sedimentation in sequence, and are then treated by an ultrafiltration system. The UF permeate enters a dedicated reverse osmosis system for desalination. The desalinated permeate is returned to the pure water tank and circulated and reused together with the freshly produced pure water. The concentrate is either further evaporated or discharged.
The distinguishing features of our coating line pure water equipment are fully automatic operation, online water quality monitoring, and the ability to integrate a wastewater reuse module, thereby helping OEMs and component manufacturers achieve water conservation and emission reduction.


Service Hotline:400-880-
E-mail:hsq@globalzx.com
WhatsApp:18808129

Products| About us| News| Sitemap| Privacy Policy