Suction of combustible and explosive dust

This guide explores all the key aspects of industrial explosive dust extraction: from choosing the right extraction system, to classifying hazardous zones, all the way to neutralization technologies such as inertization or wet collection. Below is the complete index to help you navigate the contents.

• Identifying combustible dust
• Where is combustible dust usually found?
• How to properly manage combustible dust in an industrial environment?
• How to choose the right industrial vacuum
• Which features should be considered when selecting industrial vacuum cleaners?
• Is it better to collect or neutralize combustible dust?
• How does a dust explosion ignite?
• Regulatory framework
• FAQs

Identifying combustible dust

Combustible dust is a hazard that can cause fires, explosions, and loss of life if not properly managed. The first step to mitigate the risk is to know and analyze the dust, which must be assessed in terms of its explosibility and classification. Understanding the parameters of the dust being handled is essential to eliminate ignition sources and limit the effects of explosions, minimizing injuries.

Here are some key indicators used to assess the hazards of flammable dust:

• Kst: measures how destructive a given dust can be once an explosion occurs
• Pmax: indicates the maximum pressure developed during an explosion inside a closed vessel
• LOC: defines the maximum oxygen concentration at which dust cannot ignite under ambient temperature and pressure
• MEC: determines the minimum concentration of dust required for ignition
• MIE: indicates the minimum ignition energy needed to trigger a dust explosion
• MIT: indicates the minimum temperature at which a hot surface will ignite either a dust cloud or a dust layer upon contact

Kst and St, in particular, provide an indication of the overall severity of a potential explosion caused by combustible dust.

Once the nature of the dust has been defined, it becomes possible to carry out a complete risk assessment and create a prevention and cleaning plan that trains the personnel in charge of supervision and establishes specific management procedures.

Where is combustible dust usually found?

In reality, combustible dust is a hazard that is often underestimated in many industrial and production environments. Identifying the most common places where it occurs is essential to ensure safety and prevention across various industries. Below we explore in detail the main contexts in which it is present:

• Food industry (flour, grains, sugars): Easily flammable organic particles, such as those produced during grain milling or sugar refining.
• Wood and metal (sawdust, chips, grinding dust): Finely divided materials generated by mechanical processing, with a high risk of combustion.
• Chemical and pharmaceutical (micronized compounds): Very fine powders of chemical substances, often unstable, that can easily react and cause fires or explosions.
• Plastics, rubber, paper (cutting and extrusion residues): Fragments resulting from industrial processing of synthetic and cellulosic materials, easily flammable in the presence of sparks or heat.
• Innovative sectors (batteries, 3D printing, recycling, aerospace): Metallic and polymeric dusts generated during processing or recycling phases, highly reactive and potentially explosive.

How to properly manage combustible dust in an industrial environment?

For effective and safe management of combustible dust, it is necessary to adopt precise cleaning procedures and use specific equipment. Among the safest options is the use of certified industrial vacuum cleaners, specifically designed to collect dust safely without dispersing it into the environment.

Here are some recommended best practices:

• Plan regular cleaning schedules to prevent significant accumulations of combustible dust.
• Use certified industrial vacuum cleaners to safely collect combustible dust.
• Frequently clean floors and horizontal surfaces, such as ducts, pipes, hoods, ledges, and beams, to prevent dust buildup.
• Avoid cleaning methods that generate dust clouds, such as using compressed air for blowing, especially in the presence of potential ignition sources.
• Keep operational environments consistently clean, ensuring that dust layers do not exceed approximately 1 millimeter in thickness (about the thickness of a paper clip).
• Always check that electrical devices used in dusty environments (e.g., sweepers and vacuums) comply with the specific risk classification of the operational area.

Which features should be considered when selecting Industrial Vacuums?

1. How many dust filtration stages does the vacuum cleaner have?
2. Are the filters antistatic and grounded? It is mandatory to use antistatic filters that are fully grounded to prevent sparks.
3. Is it powerful enough? The motor must guarantee an adequate airflow, maintaining at least 20 m/s for effective dust removal.
4. Are the components and motors ATEX certified? All electrical elements must bear ATEX marking and have the proper IP protection rating to operate in ATEX zones.
5. Does the supplier provide regular maintenance? Maintenance in ATEX areas must be carried out at least annually to preserve certification.
6. For which zone is the equipment approved? Check markings to ensure compatibility with the specific environment: ATEX, ACD, etc.
7. Are the accessories suitable for use with combustible dust? Make sure that all accessories are also certified to ensure complete safety.
8. Is the electrical plug compliant? Only use plugs designed and certified for work with dust, avoiding extension cords.
9. COT – Continuous Operating Temperature: The continuous operating temperature must be adequate to prevent overheating of the motor and non-metallic materials, ensuring safety even in the worst-case scenario.
10. Is it designed to prevent sparks from friction? The vacuum cleaner must include specific features, such as brass deflectors at the suction inlet and radial inlets, to reduce the risk of sparks caused by friction or mechanical impact.

Is it better to collect or neutralize combustible dust?

The choice between collecting or neutralizing combustible dust depends mainly on the final goal: if the objective is to recover the material for reuse, collecting is preferable; if the priority is eliminating risks, neutralization is the safer option.

Regulatory framework