The client uses a closed loop for cooling down the mould forms for production of PET bottles. The water is cooled by a plate heat exchanger. Due to a little leacking of the loop,This is also continuously introducing new lime scale as well as new oxygen into the loop. Causing corrosion,. The loop has to be cleaned on average every14 days. Mostly rust and a little scale. This leads to significant costs, not only the cleaning time and the chemicals used, but also in terms of shutting down the production for several hours. This cleaning was not always possible, and this leads to further serious quality problems in the bottles.

 

We installed one Merus®-Ringe in the cooling loop. In between the heat exchanger and the moulds at the machine. It was installed very near to the mould forms, in order to get the best possible results in the forms.

 

From the time of installatoin there were daily samples of water taken, which was checked for iron content by the companies lab. In a closed loop it was expected, that the iron content in the water would increase, but due to the small leackage, the rust and the scale was being drained from the system as well. So it could bee seen, that the iron content in the water decreased steadily and stabilized on a very low and acceptable value.

 

Since then it could be seen by several inspections, that there was no corrosion or lime scale in the mould forms at all. As also there was no need of chemical cleaning. The big advantage for the client, was not only that the quality of the PET bottles is constantly high, but now there is no shutdown in production.