Engineers from Dust Control Systems Ltd recently demonstrated their ability to provide effective dust extraction solutions for two wholly different production processes at Assa Abloy’s UK manufacturing operation at Willenhall in the West Midlands.
Assa Abloy is the world’s biggest lock maker with brands that include such well known names as Chubb, Union and Yale. The company’s Willenhall manufacturing centre produces a wide range of locking systems and is also home to Safeguard Doors, a leader in the manufacture of high security, bullet resistant and bomb blast doors.
DCS Ltd were called in to fully evaluate their requirements and come up with dust extraction solutions for the brass polishing and linishing workshop and for extracting dust generated in the security doors woodworking shop.
An efficient ‘capture-at-source’ solution was required in the polishing workshop to extract brass/zinc dust and mop fibres generated during the linishing and polishing of mortise lock components, cylinders and night latches. Each twin-headed lathe station and automatic polisher has been fitted with a custom-designed hood that captures and entrains the dust for transportation, via ductwork to one of three separate internally located filter units. Automatic Shaker Filters, suitable for potentially explosive dusts, have been installed to handle air volumes in excess of 11,000m³/hr. The filters are fitted with a pre-separation section to provide added volume below the filter bag; particularly beneficial when dealing with higher loadings of very fine dust. An efficient cleaning mechanism has a short, 3 minute off-line cycle time and dust is discharged into quick-release dust bins located at the bottom of each filter unit.
Recent investment in new woodworking machinery, and a decision to relocate the Safeguard Doors operation from Wednesbury to Willenhall, prompted the company to consider replacing their old wood waste extraction plant with a more efficient system capable of meeting current and future dust extraction requirements. Extraction was required for a total of seven woodworking machines plus four joiners’ benches and, like most systems today, energy saving was an important consideration.
The system proposed and installed by DCS comprises an externally sited, high-efficiency modular filter unit designed to handle large volumes of material contamination. The system has an airflow capacity of over 16,000m³/hr and is fitted with the patented Superbag polyester filter bag. Superbag employs a patented weaving technique, in tubular format, that gives the filter bag a surface which can cope with varying filter loads with all types of wood dust and chips. Collected waste is discharged ‘pressure-free’ via a rotary valve into a closed container housed beneath the filter.
Running costs are reduced through the use of variable speed technology which automatically adjusts fan speed to suit the actual volumes required. Volume is ramped up when dampers on specific machines open and lowers when dampers are closed. The project also involved the installation of a Hi-vac extraction system for four joiners’ benches with ductwork linking back to the filter unit. A further energy saving benefit comes in the shape of return air ductwork which enables filtered warm air to be fed back into the workshop in winter to reduce heating costs.