Filtermist upgrades DAMS’ extraction

Filtermist Systems Limited has recently installed and commissioned an all-embracing extraction system for Dams International – a leading UK manufacturer and wholesaler of office furniture.

Dams International boasts a 50-year heritage in the industry and, although the company now employs close to 300 people in the UK, it began life as a one-man operation in 1967. Barry Scott provided a business machine repair service and was responsible for coining the DAMS company name – Dictating & Adding Machine Service.

Barry soon expanded into office furniture sales and when presented with an opportunity to supply Liverpool Council with office desks, the company started manufacturing wooden office furniture. The rest, as they say, is history and with head office, showroom, wooden furniture and upholstery manufacturing, assembly, warehousing and distribution facilities all now located side by side at Knowsley Industrial Park, Merseyside, the company has full control over manufacturing and product quality.

Investments in equipment to support the manufacturing operation means the woodworking factory is home to a range of high-tech, high-speed equipment for large-scale furniture manufacture – all essential tools in the production of the high quality panels used in the company’s ranges of office furniture and storage systems, but all producing high volumes of waste dust that requires extraction at source.

Over the years, Dams has relied on dust and woodwaste extraction services provided by both DCS and Cades - two of the companies that recently merged with other Filtermist operations to form Filtermist Systems Limited. This prior experience meant that Dams’ production director, Michael Dingwall, had no reservations about continuing this association when the decision was taken to completely replace the old extraction system. “The previous system had just about reached its end-of-life and new machinery purchases in recent years meant the system no longer provided sufficient extraction to cope effectively if all machines were used at the same time,” Michael explained. Dams’ woodworking plant operates around the clock and extraction fans for the previous system were running continuously, at full power, 24 hours a day. “Like every business, we continually review production costs in order to remain competitive in the marketplace. The need to replace the extraction system also presented us with an opportunity to invest in a system which would not only extract woodwaste effectively, but one which could also achieve reductions in energy consumption and significantly reduce operating costs.”

In common with most furniture manufacturers, fluctuations in production volumes for particular components, and variations in product styling requirements, mean that it’s actually quite rare that all machines are in use at the same time. Consequently, as Michael Dingwall confirmed: “The old extraction system was constantly extracting at levels way above what was generally required.” Following a full review of Dams’ requirements for current and future dust extraction and woodwaste management, Steve Rhodes, Systems Sales Manager at Filtermist, put forward a comprehensive proposal for the installation of an externally-sited Moldow filter unit complete with new extraction fans, XS Automation electrical control gear, and Filtermist’s FastClip steel ducting fitted throughout. Steve Rhodes also proposed the implementation of Ecogate® energy-saving smart technology, with automatic motorised dampers fitted to all machine extraction points, and the entire system controlled by a bank of Ecogate® greenBOX controllers.

Filtermist Systems Limited is the sole UK agent for ATEX-compliant Moldow filter units and the new installation at Dams features a Moldow MHL 204-336 modular baghouse filter. Moldow High Load (MHL) filter units are constructed from galvanised steel plate and are designed for high waste volumes and continuous 24/7 operation. At Dams the system is designed to operate under negative pressure which is provided by two, low-noise, 90kW Moldow direct drive fans; each fan having the capacity to extract over 58,500m3/hr from the ‘clean side’ of the filter unit.

At the top of the MHL unit are 20 filter sections, each with an array of anti-static filter bags, providing a total filtration surface area of 700m². Extracted dust settles on the outer surface of the 2,700mm long tubular bags which taper from 150mm diameter at the top, to 100mm at the bottom. A unique air regeneration system utilises a 4kW fan to automatically and continuously clean the filter bags during operation.

Dust purged from the filter bags falls into the hopper section at the base of the unit and is then directed by a drag chain conveyor towards a rotary valve, from where the waste is discharged pressure-free. A 22kW fan transfers the discharged waste to a fuel storage silo, for use in the company’s woodwaste burner or, when necessary, diverts it via a closed-loop system to a trailer for removal from site.

The installation serves over 20 machines, with a total extraction volume requirement of 130,0003/hr, and also includes spark detection devices and explosion non-return valves in each of the four main dust extraction lines. Although the system is designed to be able to accommodate all machines in operation at the same time, the maximum requirement is normally much lower than this and varies continuously as machines come on or off-line. Ecogate® technology ensures the fans operate at the optimum levels required to maintain efficient extraction, and to extract only from machines that are in operation. As well as monitoring machines coming on or offline during a normal working day shift, the Ecogate system also ensures minimum power usage through a night shift when machine usage is general much lower. “Using our audit of machine usage at Dams we calculated that the cost of the Ecogate installation could be recovered in just 12 months,” says Steve Rhodes.

As well as looking forward to significant ongoing cost savings, Michael Dingwall was also delighted with the schedule of works undertaken by Filtermist’s installation engineers: “The Filtermist team had prepared the way for our new filter to be installed over the Christmas shut-down and, by the first day back after the break, the new filter installation was completed and operational.”

For more information contact Filtermist Systems Limited on 01952 290500 or email