When it comes to working in potentially dangerous environments, safety is a top priority. Equipment for explosive atmospheres, also known as ATEX equipment, refers to devices specifically designed for safe use in potentially explosive environments. ATEX stands for“ATmosphères EXplosibles“, a European directive governing the use of specialized equipment in such environments.
The aim of ATEX equipment is to prevent these explosions by ensuring that the equipment used is suitable for these environments, so as to minimize the risks.
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What is an explosive atmosphere?
An ATEX explosive atmosphere is an environment where flammable substances, such as gases, vapors, liquids or dusts, are present in sufficient quantities in the air, creating a potential risk of explosion. The term “ATEX” refers to European Directive 2014/34/EU, which regulates the use of equipment in these hazardous atmospheres.
Explosive atmospheres can form in many different types of industries and workplaces, such as the chemical, oil and gas industries, waste treatment facilities, the pharmaceutical industry, mining, the food industry and so on. Flammable substances present in these environments can be released accidentally, for example through leaks, spills, chemical reactions or specific production processes.
For an atmosphere to be considered explosive, two key elements must be present simultaneously: the fuel and a source of ignition. The fuel may be a gas, vapor, dust or flammable liquid, while the ignition source may be a spark, open flame, hot surface, electrostatic discharge, etc.
Classifications of explosive atmospheres
To better understand potential hazards, explosive atmospheres are classified into different zones according to the probability of occurrence and the duration of the presence of flammable substances. The most commonly used classification is that defined by the ATEX standard, which divides zones into three categories: Zone 0, Zone 1 and Zone 2 for gaseous atmospheres, and Zone 20, Zone 21 and Zone 22 for dusty atmospheres.
Here are the main classification zones for gases, vapours and dusts:
- Zone 0 (gas/vapor) or Zone 20 (dust): An explosive atmosphere is present continuously, for long periods or frequently = 1000 hours/year.
- Zone 1 (gas/vapor) or Zone 21 (dust): An explosive atmosphere is likely to occur during normal operation = between 10 and 1000 hours/year.
- Zone 2 (gas/vapor) or Zone 22 (dust): An explosive atmosphere is unlikely and occurs in negligible quantities over a short period = less than 10 hours/year.
It is essential to take appropriate preventive and safety measures in ATEX explosive atmospheres. This includes the use of ATEX-certified equipment, the implementation of safe work procedures, personnel training, environmental monitoring, the management of ignition sources and flammable substances, as well as the implementation of appropriate protective measures to prevent explosions and minimize risks to the safety of workers and installations.
ATEX equipment
ATEX equipment is specially designed for safe use in potentially explosive atmospheres. It is manufactured to limit the risk of explosion, using specific design and construction techniques. It includes a wide range of equipment such as luminaires, motors, switches, sensors, communication devices and measuring instruments.
ATEX equipment must go through rigorous certification processes to ensure compliance with the required safety standards. Manufacturers must provide detailed information on the appropriate protection category, temperature class and classification zones, as well as other safety features on their products.
ATEX equipment can be divided into two main categories: equipment for gaseous atmospheres and equipment for dusty atmospheres. Each category has specific features designed to ensure safety in potentially explosive environments.
Equipment for use in gaseous atmospheres is designed to prevent the formation of sparks or electric arcs that could trigger an explosion. They incorporate protective features such as explosion-proof housings and seals to prevent the ingress of flammable gases. This equipment is made from explosion-resistant materials and is designed to minimize the risk of ignition.
Equipment for dusty atmospheres is specially designed to prevent the accumulation of combustible dust. They are equipped with features such as special filters to retain fine particles, dust removal systems to eliminate dust deposits, and smooth surfaces to prevent flammable dusts from adhering. This equipment is designed to minimize the risk of dust ignition and explosion.
In both categories, ATEX certification is essential to guarantee compliance with the required safety standards. Manufacturers must provide detailed information on the compliance of their equipment with ATEX directives, including the classification zones for which it is suitable.
In our ATEX equipment range
Our technical decoupling devices
- Our ATEX check valves are designed to withstand explosion pressure. They are indispensable in ATEX dedusting systems, protecting operators and machines from explosion feedback from the deduster to production. This will contain the spread of the explosion and, above all, prevent any fatal injuries.
- Our decouplers (180° baffles) upstream of the dust collector to decouple a plant from the rest of the process if the explosion comes from the process.
- Our locks are ATEX-certified for flameproofing and resistance to explosion overpressure.
Our explosion relief or suppression devices
- Our explosion vents.
- Our Indoor discharge devices.
- Our explosion suppression systems (inerting, extinguishing).
Our suction units
ATEX version
Our EPUR B Ex 1000 and 3000 ranges are mobile extraction units designed to extract welding fumes, solder, dust, vapors, solvents and gases. Highly versatile, they can be adapted to virtually any industrial sector thanks to their three filtration stages. Controllable via a touch screen or remotely for excellent ease of use, they are quiet and powerful, so you can vacuum up to three workstations or production machines.
ATEX version
VACUMAT has been specifically designed to eliminate odors and other gaseous pollutants directly at source, using a suction arm or extraction hood. Equipped with a high-performance double filtration stage, it can be used to extract one or more sources of pollution. Filter replacement is simple, thanks to the hour meter for estimating the frequency of activated carbon replacement. This easy-to-use device is ideal for all types of industry.
ATEX version
The DUSTOMAT 4 is suitable for virtually all industrial sectors. It can extract dust directly from the production machine, but can also be connected to an extraction hood, an extraction arm or a network of ducts. It has been designed to provide efficient, high-performance air circulation, quietly and with very low energy consumption. It is equipped with a pre-separator for heavy and coarse particles. Compressed-air cleaning facilitates maintenance and guarantees the longevity of its filter cartridges.
ATEX version
Our range of DUSTOMAT HYDRO dust collectors are wet process dust collectors capable of directly extracting metallic and highly flammable dusts such as sparks.
The innovative water separation technology ensures safe vacuuming.
ATEX version
The DUSTMAC ATEX version is a cartridge or baghouse dust collector equipped with indoor or traditional membrane explosion vents, an ATEX lock and upstream and downstream explosion decoupling systems.
This device is generally zoned zone 20 indoor and zone 22 outdoor when explosive dusts are involved.
ATEX version
DUSTMAC in ATEX version is a cartridge or bag dust collector in ATEX version equipped with indoor or traditional membrane explosion vents, an ATEX lock and upstream and downstream explosion decoupling systems.
This device is generally zoned zone 20 indoor and zone 22 outdoor when explosive dusts are involved.
DUSTOMAT DRY is a dedusting system ideally suited to a wide range of industrial sectors. Available in four power levels, it is suitable for medium flow ranges from 2000 to 3500 cubic meters per hour.
Despite its considerable suction power, the DUSTOMAT DRY remains remarkably quiet and energy-efficient.
What are the criteria for choosing the right ATEX equipment?
A number of factors are fundamental to the design of an ATEX installation.
Dust characteristics
The characteristics of ATEX dusts include specific parameters that determine their flammability and explosibility. Here are the main features to consider:
- Kst (pressure rise constant): Kst is a value representing the rate of pressure rise in a dust explosion. It indicates the severity of the explosion and is expressed in bar.m/s. The higher the Kst, the more violent the explosion.
- Pmax (maximum pressure): Pmax is the maximum pressure reached in a dust explosion. It is expressed in bar and is used to determine the force of the explosion. A higher Pmax value indicates a more powerful explosion.
- Minimum explosion concentration (MEC): The MEC is the minimum concentration of dust in air necessary for an explosion to occur. It is expressed in g/m³ and varies according to the type of dust. Dust concentrations in excess of the MEC present an explosion hazard.
- Degree of fineness : The degree of fineness of ATEX dusts represents the particle size. Finer dusts tend to be more flammable and more likely to form an explosive mixture with air.
- Humidity : Dust humidity can affect flammability. Some dusts are more flammable when dry, while others can become more flammable when wet.
It’s important to note that each type of dust has its own specific characteristics. It is therefore essential to know the precise characteristics of the dusts present in your working environment in order to choose and correctly size the ATEX equipment needed to minimize the risk of explosion.
There are several possible solutions for obtaining the necessary data on ATEX dust characteristics:
- Analysis of a representative sample: You can have a dust sample analyzed that is representative of the dust aspirated in your working environment. This will provide precise data on the flammable and explosive characteristics of these specific dusts.
- Search existing databases : You can search for similar dust samples already tested in available databases. The most comprehensive public database is the GESTIS-CARATEX POUSSIERES database: https://staubex.ifa.dguv.de/explosuche.aspx?lang=f. This database groups together the flammability and explosivity characteristics of over 6,000 dust samples from various industrial sectors. It is a valuable tool for preventing the risks associated with flammable dusts, and helps to design protective measures against dust explosions in plants or processes using powdery materials.
By using these solutions, you can obtain the information you need on ATEX dust characteristics to correctly size your equipment and implement the appropriate safety measures.
Presence or absence of ignition sources and/or safety devices to suppress them?
It is essential to take into account the potential presence of ignition sources and/or safety devices to suppress them when working with explosive dusts. This applies in particular to explosive metal dusts (aluminum, titanium, etc.) or explosive organic dusts (wood, sugar, organic powders, composite materials, glass fibers, carbon fibers, resins, etc.).
If the extraction of explosive dusts is associated with the potential presence of ignition sources such as sparks, incandescent particles, hot spots or flames, it is imperative that the dust collector is adapted and dimensioned to withstand a possible explosion. The dust collector must be designed to withstand the pressure generated by the explosion, and can be fitted with devices such as explosion vents and ATEX decoupling devices (non-return valve, decoupling baffle, quick-closing valve, inerting, etc.).
On the other hand, if the explosive dusts extracted are not associated with the potential generation of ignition sources by the process or machinery, it is possible to install a dust collector dimensioned in such a way that it does not itself constitute a source of ignition, for example by avoiding the risks of heating or of electrostatic discharges.
Zoning of the installation site
When installing a vacuum system in an explosive atmosphere zone, it is essential to take into account the zoning of the area. It is essential to know the zone classification and to ensure that all equipment in the extraction system complies with ATEX requirements for the specific zone in which it is installed. For example, a dust collector may suck in explosive dust, but be installed in a non-classified zone (outside the ATEX zone), in which case the risk associated with the sucked-in dust will be the main concern.
If the dust collector is installed in an explosive atmosphere zone, it is necessary to check that all the equipment in the extraction system conforms to the zone in which it is installed.
Correct selection of ATEX equipment is crucial, as the consequences of the wrong choice can be far-reaching. If you’re doing your own research, you’ll need to know the type of pollutant present in your work area, whether gaseous or solid. These searches will enable you to select the appropriate type of filtration and determine the corresponding ATEX zone.
Next, you’ll need to find out how powerful the device is, i.e. its flow rate. The unit’s flow rate will depend on the quantity of pollutants to be treated and the surface area of the area to be treated: the larger the area, the greater the flow rate required. You’ll also need to determine the accessories required to equip the unit, such as a sheath to connect it to the production machine, or a suction arm for a specific workstation.
The Obera team is at the disposal of customers who wish to benefit from professional support in choosing ATEX equipment, dust classification or ATEX zoning for their workshop. Our expertise and experience enable us to offer personalized advice and guarantee compliance with safety standards, ensuring our customers’ peace of mind in their sensitive industrial projects.