Dust produced by woodworking operations is abrasive and poses a challenge for industrial ventilation. Millwork 360, a large millwork company in the southeastern United States had serious downtime and emissions problems due to abrasive dust—and helped solve them with the right filter technology.
A major producer of custom interior and exterior doors and moldings, Millwork 360’s shop generates wood dust from a number of planers, sanders, saws, and shapers. Fine sawdust mixes with chips and shavings to create an extremely dusty environment that can be difficult, if not harmful, to work in.
The company had a large, properly sized baghouse dust collector, but noticed that dust was often bypassing the filter and exiting the stack outside the building. On closer investigation, operators discovered that filter bags near the collector’s high inlet were abrading due to perpetual contact with course dust. The abrasion problem occurred so regularly that compliance with emissions standards became a concern. The torn filter bags required frequent replacement, causing unplanned downtime which incurred heavy costs in terms of lost production, new filters and filter servicing.
Donaldson Company recommended that the facility replace 25 standard felt bags and cages near the inlet with pleated filters made of sturdy spunbond polyester. The 80-inch pleated filter bag contains 2.5 times more media area than the 120-inch standard filter bag. The shorter length of the pleated means that the filter bag is not directly exposed to the abrasive dust at the inlet, and it doesn’t extend into the dust laden drop out zone of the collector. As an added bonus, the short length and cage-free design of the pleated filter bags equate to quick and easy filter installation.
The solution worked. Inlet dust does not abrade the shorter, pleated filter bags and the shop’s uptime improved dramatically. The facility has transitioned another 125 standard filter bags and cages to pleated filter bags for a total of 150 in the 276-element dust collector.
Recently, with a boom in the construction industry, the company expanded and added a new, Donaldson Torit RF baghouse to their dust collection system. The new baghouse was delivered with pleated filter bags, which increased the available filter area by 235% over standard filter bags. This additional media area reduces the air to cloth ratio which in turn, reduces system pressure drop across the filter and therefore, increases filter life. The 356 pleated filter bags in the Torit RF have been in use for three years without abrasion issues or replacement.
According to the plant manager, the air is visibly cleaner since the move to pleated filter bags, and the mill has been able to take on new business without expensive unplanned downtime. The high costs associated with premature wear of standard filter bags and cages have been eliminated.