• Cyclofilters offer high waste capacity and a small footprint.
• In the UK there is an even split between cyclofilters and chain filters.
• Chain filters can be modified and expanded.

Cyclofilters, named after the cyclonic action affecting the dusty air as it enters the filter unit, are regarded for their high waste capacity and small footprint.

Danish-owned Dantherm Filtration, which makes cyclofilters in France, formerly branded as Cattinair but now known as Cyclopac and Cyclopex, says three-quarters of its installations are cyclofilters. In the UK, its installations are more evenly split between cyclofilters and traditional chain filters.

But Dantherm’s UK technical and marketing manager Gus Bishop said more UK customers were moving towards cyclofilters. The technology has also made its mark in France and the US, but the chain filter still holds sway in Scandinavia and South-east Asia.

Mike Johnson, sales director at Air Plant, one of only a few UK manufacturers of dust extraction technology, concurred that the force was with cyclofilters.

“People are upgrading. The bigger, newer installations are all going over to cyclofilters,” he said. “That’s the way forward. They need very low maintenance, their impact on space is very small and you can run them for long hours.”

The machinery was expensive, but they could process high volumes of wood waste, he added.


The core technology had not changed much in recent years, he said, but improvements to pressure sensors, invertors (which control the speed of the fan) and filter sleeves had improved efficiency.

But Mr Johnson said the extraction technology often now had to be more powerful due to the smaller hood size on modern woodworking machines. More pressure was needed to suck the chippings and dust away, which ultimately meant more noise and energy use.

Air Plant’s cyclofilters are fully cone shaped at the bottom and work on negative pressure, with the advantage of having the fan out of the waste stream.

Dustraction redesigned its Dustrax cyclo in 2007. “We’ve been installing cyclo filters for the past 15 years and have had nothing but praise regarding their reliability and performance,” said sales director Steve Matuska.

He said the only moving parts on the Dustrax system were the compressed air operated diaphragm valves. Filter bags are guaranteed for three years or 6,000 hours as well as guaranteed emission of 0.2mg/m.”

One of the important points for woodworking companies to consider with cyclofilters, said Mr Bishop, was the need to build in extra capacity to allow for future expansion, as the technology was not as easy to extend as conventional chain filters. Another consideration was the running costs.

Chain filter technology

But the future is not exclusively cyclofilters. Dust Pollution Systems says that the longevity and easy modification of traditional chain filter technology was also an attractive option.

Dantherm agrees. “If your fan is too small and you need more capacity, they can be extended quite easily,” said Mr Bishop.

Dantherm recently launched an updated range of chain filters – the NFZ3000, which boasts a negative pressure operation with a clean air fan, a space-saving upward facing explosion relief and a quicker build method than the previous range. Dantherm says more powerful fans and improved internal design lowered air resistance and reduced energy consumption.

Meanwhile, Dust Control Systems has added turnkey extraction packages to its portfolio. The packages come as shaker or pulse-jet action, comprising filter, fan, starter, duct, also including delivery and installation. Small to medium-size companies have expressed interest in the packages, which are complemented by a 100m³ capacity galvanised waste storage silo with discharge mechanism.