Cleaning and Pretreamtent Before Painting

General task requirements for cleaning and pretreatment recycling systems:

  • Consistent high cleaning and pretreatment quality by using high quality rinsing baths
  • Default conductance in µs for the rinsing water
  • Minimization of operation and disposal costs
  • The possibility to prepare active baths

Specific customer requirements:

  • Considerable cost reduction by recycling instead of disposing wastes
  • High quality distillates, without salt or oil residues
  • Anti-foaming agents cannot be allowed to enter the cycle
  • Waste reduction
  • Short amortisation periods
  • For concepts with combined VE-plants: distillate temperature below 35 °C

Specifics of recycling systems for rinsing baths using evaporators:

Active baths such as degreasing or phosphating baths can be prepared in rinsing baths or by using evaporator technology. Depending on the specific ingredients being used, it may be necessary to adjust the pH-value.

Rinsing techniques directly influence the investment and operating costs of waste water systems. This fact is often neglected when plants are designed. Experience shows that even minor modifications and adjustments in the system can considerably reduce the amount of waste water produced. It is definitely worth considering consulting a specialist during the planning phase.

System description:
The rinsing baths are collected in a storage tank in order to be prepared. If further active baths need to be prepared, then these are fed from a second tank.
The Evaporator ET safely separates the salt, surfactants, oil and dirt from the water. The distillate is added in the last sink, usually using a circular spray nozzle, and it is then cascaded all the way into the first sink. There, the used rinsing water is removed and fed into the evaporator. Treatments, such as degreasing, can contain volatile hydrogens or surfactants. The residual oil separators, which are integrated into the Evaporator ET, guarantee that even minute amounts of volatile oils or surfactants are prevented from entering the cycle. The distillate which is produced during the cleaning process is reintroduced into the system in the last sink.
That which is lost through evaporation and carry-over during the cleaning cycle is replaced by reverse osmosis.

In case of high throughput or special treatments it is recommended to use the VE- recycling sinks.
The accumulation of concentrates during the preparation of rinsing baths is minimal, usually well below 5%.

System ET: Goals which have been achieved in practice

  • Minimal operating costs thanks to extremely low energy consumption
  • Best distillate quality guaranteed by integrated residual oil separators and air ventilation systems
  • No contamination of the distillate by anti-foaming agents
  • Frequency controlled compressor motors provide for high concentration and minimal waste concentrates
  • Short amortisation periods thanks to the high efficiency of the system
  • Optimal heat recovery in the System ET means that the distillate temperature remains low. Because of this, complex procedures which (re)cool the distillate are not necessary. The evaporator system can therefore be combined with VE-plants