Self-cleaning filters
Euroimpianti supplies self-cleaning filters to install on our surface treatment lines, for removal and purification of process mud which form on the tanks bottom, in which phosphodegreasing treatments are planned.
The use of phosphodegreasing products allow both the pollutants removal on the pieces surface to treat (thanks to the presence of surface-actives and solvents) and the deposit of a thin layer (a few microns thick) of amorphous iron phosphate providing a protection against corrosion in addition to allow a good anchorage substratum for coating.
But the action of phosphoric acid strives for removing from the surface of the treated pieces and bringing iron ions in the bath which, joining with phosphates present in the same one, lead up to the formation of insoluble iron phosphates which settle on the tanks bottom, creating mud.
So the use of these products leads to the request of a specific disposal, because of high content of present phosphates, with concerning increase of the process burden. In addition, the frequency of baths regeneration is increased.
Therefore the application of self-cleaning filters, to place side by side to tanks with this type of treatment, leads up to evident advantages in duration and quality of the baths.
Regularly the self-cleaning filters take a sample of the liquid from the tank bottom, subjecting it to the filtration treatment and putting again the liquid without impurities in the circuit.
Cleaning mechanism consists of pushing the liquid to treat through a cartridge,with a degree of in a filtering sized for interest impurities (from a minimum of 100 microns to a maximum of 2000 microns). At the center of the filter a tree with scrapers is placed which, rotating, frees the external surface of the filter element from contaminant settling on the filter bottom so it is expelled outside by an exhaust valve.
Self-cleaning filters are entirely made of stainless steel 304 and equipped with control unit for an easy programming of cleaning cycles.
Normally through control PLC of painting plant, a cleaning cycle is immediately planned after the start of the tank recirculation pump where the filter is connected to remove any sediments caused by downtime.
