The importance of finishing in technical filtration fabrics

A customer dedicated to animal nutrition tells us that he is having problems with a new dust collector baghouse. It has a lack of suction capacity and he cannot find the reason.

Our technical team inspects the filter and we see that the pressure drop is really high. It is a new filter, well sized, with sleeves supplied by the filter manufacturer and with only one week of operation. We verified with the technical data sheet, provided by the manufacturer, that the fabric is of the same quality that we would have recommended and we found that the filter cleaning system is working properly. At this point, we requested access to the inside of the filter and that they provide us with some sleeves for analysis.

After the study, we concluded that the sleeves were made upside down. The technical filtration fabrics have a finish called gassing, which is applied on one side only, the side in contact with the product, as it means a certain resistance to dust adherence. In this case, when manufacturing the sleeves, the side of the fabric with the finish has been left on the inside and therefore the dust is adhering directly to the side of the fabric without the finish. This causes the dust to adhere to the sleeve and form a dense precoat that hinders the passage of air.

We propose the replacement with new sleeves made with the finish on the outside. After a few days working with the new bags, the customer informs us that the filter is now working with optimum pressure drop values.

The knowledge of the finishes and their correct application at the time of the manufacture of the spare part and its installation in the filter is another determining factor for the good operation of the installation.