The laboratory of FIMIC
In the Fimic filter there is a scraper with two blades that starts its cycle when the pressure in the chamber has reached a threshold, collects the contamination caught by the screen and stores it in its cavity. When the scraper stops, a valve, air or oil managed, opens to discharge the contaminants. Differently from other filters, which discharge continuously through an auger, the Fimic valve discharging system enables the equipment to manage higher level of contamination and to discharge only when needed. In fact, with this system the discharge takes place only when the valve opens and this happens only when the scraping cycle is concluded.
The Fimic filter remains in the machine with a shorter screen changing time compared to other automatic filters. The process takes about 30 minutes, with a frequency that can go from three days in a week to a maximum of once every 15 days. This obviously depends on the level of contamination in the material, with no limits in the type of contamination: paper, wood, metal, sand, glass, rubber, aluminum, other types of polymers. The customer only has to choose the level of filtration among the wide range of offered possibilities (from 100 to 1500 microns).
Recently, one of Fimic customers, which deals with the processing of solid urban waste, has inquired for a method for reducing the screens changing time, to approximately 5 minutes, through a modification of the cover opening. This was requested because the contamination in this stream is so high that the necessity of changing the 500 microns screen goes down to once every day. Fimic solution was to apply a closing system with jaws and pistons, which in fact reduced the opening, screen changing and closing of the filter to minimum of 5 minutes all together, so that the downtimes have been considerably reduced.
The same system has been applied for the new Fimic filter for PVC, that is going to be tested soon and consequently introduced onto the international market. PVC still represents a difficult product to treat. For this application, companies generally use manual filters. Adding an automatic filter in this specific field will facilitate the recycling of the material that is now scarcely recycled although strongly used.