Explosion risk in production

06 November 2019

John Brill, Sales Director for Nilfisk discusses the important issue of managing hazardous material in a production environment...

Manufacturing output in the UK accounts for 11% of economic contribution, whilst this figure seems low there are still hundreds of production sites where everyday materials present a real risk to life. Understanding the risks is key.

How does dust and gas explode?

An explosion or fire will occur if a combustible substance is present together with oxygen and an ignition source. Dust particle size is particularly relevant as smaller particles disperse easier in the air and increase risk significantly.

Combustible dusts include; cereals, flour, starch, sugar, animal feed, light metals, coal, plastics and textiles. Combustible gases include propane, ethylene and hydrogen in addition to gases created by the evaporation of organic solvents such as alcohol, hydrocarbons and lubricating oils. 

Certainly, quite a list and if standard vacuum cleaners are used around these materials, they will provide an effective ignition source to fuel the fire. 

In simple terms ATEX certified Industrial Vacuum Cleaners eliminate the ignition trigger, removing the source of ignition, making vacuum cleaning operations safe in production areas.

Understanding zones

Areas where there is a risk of explosion are divided into Zones based on the frequency and duration of the presence of explosive atmospheres.

Dusts are separated into Zone 20, 21 and 22 whilst gases, vapours and mists are divided into Zone 0, 1 and 2. 

The responsibility for classifying the work area where a vacuum cleaner will be used lies with the facility, so it is critical to seek informed advice. Once a Zone is decided it is the machine manufacturer who is responsible for supplying the correct machine to meet the requirement. A declaration of conformity should be issued with each machine. The ATEX Directive also requires that the machine is marked with the symbol EX in a yellow hexagon.

There is obviously no room for error, it is vital that advice and recommendations are sought from an experienced source. This is not an arena to cut corners, the threat is daily, and it is very real.

Nilfisk ATEX product range

Nilfisk manufacture a complete range of ATEX certified industrial vacuum cleaners designed to respect the strictest safety standards. The range extends from mobile vacuum cleaners to centralised vacuum systems.

In addition to removing a source of ignition ATEX machines trap dust so that the particles do not alter the classification of the Zone in which they are used. In the presence of gas, the vacuum cleaner traps dust and expels the gas from the outlet. The customer therefore needs to consider if it is appropriate to install ducts to pipe the outlet out of the immediate environment.

Site Surveys

Given the very real threat to life it is essential that the facility seeks professional advice from within the Industrial Vacuum sector. Environments can vary enormously, and requirements will fluctuate if changes are made to production materials.

Nilfisk UK have a specialist IVAC division dealing solely with the needs of this sector. Site surveys are available across the UK from experienced members of the team, so customers are advised to avail themselves of this opportunity.