Guest Author: Andy Collar
What do the fatal West Pharmaceutical Services Explosion in 2004 (Kinston, NC) and the Hoeganaes metal dust flash fires in 2011 (Gallatin, TN), have in common?
The severity of these devastating explosions were increased by high level combustible dust that had accumulated above the workers heads in the facility. At West Pharmaceutical, the dust accumulated above false ceiling tiles, while at Hoeganaes, it accumulated no rafters and beams (image right).
Accumulation of combustible dust at heights in powder processing facilities is a major concern for both primary and secondary explosion incidents. This post reviews the hazard of high-level combustible dust and describes the cleaning solution provided by SpaceVac, who specializes in cleaning these areas.
The Problem
Several excerpts from the UK Health and Safety Executive guidelines for Safe Handling of Combustible Dusts (HSG103) illustrate the importance of high-level combustible dust cleaning:
“Air currents will carry the finest dust particles a considerable distance and allow them to settle at high levels within a building. Dust deposits on beams and ledges at high level create a secondary explosion risk.”
“Do not neglect the highest parts of buildings as these are the areas where the finest and most hazardous dust can be found. “
“..the preferred [cleaning] method is a vacuum system rather than brushes and shovels, which tend to raise dust clouds. You should avoid the use of compressed air lines to dislodge dust deposits as this will cause unnecessary dangers by creating dust clouds.”
These excerpts illustrate that housekeeping practices which ignore the higher parts of the facility including the top of machinery, pipework, cable trays, and ducting expose workers to significant secondary dust explosion hazards.
Area Classification
These specialist environments are designated as ATEX environments – named after the European directive governing hazardous environments and the equipment required to work within them. ATEX covers a range of designations based on the particular hazard but most of the food & drink operators, tend to fall within the zones 21, 22 designation covering dry food storage and handling.
An At-Risk Industry
One of the first sectors that quickly saw the need to remove high-level dust was the Food & Drink sector who often find themselves dealing with the issues our system set out to help resolve. By its very nature, Food & Drink oftentimes requires the transportation, storage and processing of all kinds of raw ingredients – from flour and wheat through to sugar, salt, pepper and many more. When working with these materials there are always residual dust left behind which – due to the light weight of the particles – will often float upwards and settle on the way back down to earth – on top of machinery, pipework, ducting and anything else standing between it and the floor.
While some sugar cast-offs might not seem like a huge issue on first glance, as regular readers of this site will be aware, these kind of organic matters – when in a confined space and deflagrated dispersed into regular air can be especially hazardous – creating the perfect environment for an explosion (deflagration)! In these situations – all that would be required to ignite a massive explosion would be a source of heat i.e. a single static spark and so it is crucial that food & drink operators not only deploy the correctly rated equipment but also maintain regular cleaning and maintenance to prevent the build up of these potentially combustible materials.
The SpaceVac Solution
SpaceVac is a revolutionary high-level cleaning system that provides a fast, cost efficient and safe way of cleaning high-level areas inside and out from the safety of the ground floor.
The system is built around a set of lightweight carbon fibre cleaning poles accessorized with a range of specialist heads, tools and brushes to offer a solution for cleaning guttering, downpipes, hoppers, ducting, pipework, vents and much more. The flexible, interconnecting system allows the operator to access even the toughest to reach and most inaccessible areas without the need for ladders, scaffolding or cherry pickers.
SpaceVac also produces an ATEX certified version of its system (protected by a worldwide patent) that enables the technology to be utilized in ATEX designated explosive atmospheres. The safe removal of the hazardous dusts and by-products that can accumulate in these areas is a crucial part of Facilities Management in these specialized environments.
To learn more about the SpaceVac solution and how it can help your high-level combustbile dust cleaning needs visit their website spacevacinternational.com.
References:
Andy Collar is the Technical Manager of SpaceVac International – overseeing the entire design and manufacture process. Andy’s considerable expertise in ATEX was a driving force behind the development of the SpaceVac ATEX Cleaning System.