Fume extraction systems linked to high temperature industrial processes, such as lasers, need to take account of potential fire risks, which is why technology developed by BOFA incorporates numerous critical safety features.
BOFA engineers map every area of any given process to ensure that models such as the AD Oracle iQ and AD 1000 iQ – designed for the laser industry – not only perform to specification by removing airborne contaminants, but also counteract the risk of fire.
This starts with the use of fire-resistant materials for casings and filters and extends to triple thermal cut-out protection should overheating occur for any reason.
The objective is to design-out the primary fire risks associated with any high temperature industrial process, particularly where a combustible dust can be drawn into the filtration system.
One fundamental advantage of BOFA technology is the use of a steel box as part of its patented DeepPleat DUO pre-filtration system. The DeepPleat concept uses reverse flow operation to reduce the velocity of contaminant as it enters the filter chamber, which means that larger particulates fall into the steel drop-out chamber, before the smaller particulates are drawn into the main High Efficiency Particulate Air (HEPA) filter and a layer of activated carbon.
This pre-filter stage is critical in combatting any fire risk, because larger particles remain hotter for longer, so ensuring that these are captured within the steel drop-out chamber is key. Smaller particles lose heat energy much more quickly and are safely retained within the sealed 200mm deep pleat layer of non-flammable borosilicate media.
BOFA is the only company to use borosilicate media mounted inside a steel box – this contrasts with flammable MDF boxes and cloth filters used in some competitor systems.
In addition to the use of fire-resistant materials, BOFA also incorporates three heat activated safety cuts outs into its iQ extraction units. Should the internal temperature reach 60ºC, which is the temperature at which the activated carbon filter becomes ineffective, the unit will automatically shut down and display a warning fault on the iQ control screen.
For processes where there is a significant risk of a burning ember or spark being drawn into the extraction unit, BOFA goes further, offering enhanced protection through its inline FireBox system.
This unit incorporates a fire extinguisher discharge mechanism – a special plastic hose, coiled around the inside of the filter box top plate, which dispenses a fire suppressant gas in the event of a fire, and gives an electrical signal which activates an on board fire extinguisher, protecting the fume extractor and other areas nearby. It activates if the surface temperature exceeds 63º C.
As a secondary and extra safety measure, the filter unit also has a temperature sensor positioned in the air flow path, which triggers a shut-down of the system should a fire develop in the pipe work leading to the filter unit.
To find out more about BOFA innovation, call +44 (0) 1202 699 444 or email [email protected].
