Polishing off the pies

A Midlands-based company process-ing ingredients used in pork pies has overcome dust emission problems using the Ravlex MX, designed by Ravensworth.

The embedded surface-filtration membrane consists of a microporous fluoropolymer coating applied among the surface fibres of needlefelts. This provides a durable, washable filter, delivering good cake release and preventing the blinding that occurs with standard "depth filtration" needlefelts. The original filter media on the "shaker" unit was 350gsm "singed" polyester that was blinding with an oily, sticky residue from airborne contaminants. This meant the bags needed replacing after just six weeks due to massive pressure-drops and fine particles forcing their way through the filter media and contaminating the exhaust air. Meanwhile, oily residue was soaking into the membrane fabric to such an extent that it could not be recovered through laundering. Ravlex MX significantly improved the bag life of the original system from only six weeks to in excess of six months. Testing of Ravlex MX on 350gsm needlefelt bags showed virtually zero pressure-drop and zero contamination of the exhaust air stream over a six-month test period. The bags can be laundered for re-use up to three times. Ravlex MX can be specified on a range of filtration media including homopolymer acrylic; epitropic polyester; polyester stainless steel; polyester or polypropylene; Ryton; Nomex and PTFE materials, and offers proven performance on envelopes; shakers; multipockets; fluidised bed dryers; pulse jet; reverse air industrial vacuum cleaners; pleated cartridges and vacuum conveyance.