Explosion hazards are a serious threat in industrial production facilities, both from potentially explosive gas mixtures and from the atmospheric environment. The safety of the production facility and, above all, the employees is the top priority. Against this background, it is crucial both to prevent explosions and to ensure that damage is limited in the event of ignition. This is where explosion-proof fans come into play.
With tested components and design, they help to increase safety in operation. As an experienced service provider for fans and compressors, Serafima is your competent partner for all questions relating to explosion protection.
Explosion-proof fans Definition
Explosion-proof fans, also known as Ex fans or Ex ventilators, are systems and machines that may be used in industrial environments where there is a risk of explosion due to the handling of chemicals and gases. They are designed in accordance with the ATEX directive, which regulates the use of fans in potentially explosive atmospheres in Europe, but is also frequently used worldwide as the basis for explosion protection. This directive classifies the potential hazards into different zones, including Zone 20, Zone 21 and Zone 22 in the area of dust explosion protection and Zone 0, Zone 1 and Zone 2 in the area of gas explosion protection.
The ATEX directives specify strict requirements for the design of fans, including the motor and other electrical attachments, both for axial fans and centrifugal fans. This ensures safe operation in environments where there is a potential risk of explosion.
Areas of application for explosion-proof fans
Explosion-proof fans are used in various branches of industry where there is a risk of explosive atmospheres or where explosive gases are conveyed. These include the chemical industry, the oil and gas industry, refineries, the pharmaceutical industry, mining and other sectors in which hazardous gas mixtures can occur. Potentially explosive atmospheres are created by the presence of hydrocarbon-air mixtures, vapors, mists or dusts that are flammable under certain conditions.
When is an EX fan necessary?
Ex fans are required in industrial spaces or outdoor areas where there is a risk of explosions due to the handling of chemicals and gases or due to high temperatures. These special explosion-proof fans have been developed to minimize the risk of explosion and enable explosion-proof extraction of air or conveyance of explosive gas mixtures. A centrifugal fan, explosion-proof, is characterized by a design that minimizes the potential sparking of the machine itself, but also in all electrical attachments. In areas where sparking cannot be completely ruled out, the encapsulated design is often used. This applies not only to the fan itself, but also to all of its electrical components or the motor.
For operation in potentially explosive areas, all ATEX fans, regardless of whether they are roof fans or other variants, must have the appropriate certifications. An ATEX fan belongs to the group of industrial fans and meets special requirements in terms of performance, quality and technical design. Every electrical and mechanical part of these fans is carefully selected. Explosion-proof fans are manufactured in accordance with strict safety standards.
The explosion protection document – when is it needed?
An explosion protection document in accordance with the Hazardous Substances Ordinance is required if hazardous explosive mixtures can occur in a company without protective measures being taken. This document serves to describe appropriate precautions that ensure explosion protection in the company. The creation of an explosion protection document is a requirement of the Ordinance on Industrial Safety and Health and is carried out as part of the risk assessment.
The document must be prepared for all potentially explosive atmospheres and must demonstrate that the explosion hazards have been identified and assessed and that suitable measures have been taken to achieve the explosion protection objectives. Regardless of the number of employees, the employer is obliged to prepare the explosion protection document before the start of work.
The form of the document is not prescribed, but all relevant documents and data that contribute to the assessment of the explosion hazard can be added, such as operating instructions, organizational measures, risk assessments and alarm and hazard prevention plans.
What information is important when selecting Ex fans?
There are three Ex protection zones: 0, 1 and 2, and the classification into these categories is important as not all products need to be designed for the highest Ex zone 0. It is a common misconception that products can only be used in hazardous areas if they are labeled. In fact, only products that fall under the ATEX directive and have potential ignition sources must be labeled. If a product does not have such an ignition source, it can be used safely in an Ex zone and does not need to be labeled in this case.
Devices in hazardous areas are marked by affixing the CE mark and the hexagonal Ex mark. The CE mark and the Ex mark are followed by the device group and the device category. An additional letter “G” or “D” indicates whether the device is suitable for use in potentially explosive atmospheres caused by gases, vapors (“G” for “gas”) or combustible dusts (“D” for “dust”). For example, a device with the marking “2 G” is suitable for use in zone 1, where explosive atmospheres caused by gases, vapors or mists may occur, while a device with the marking “2 D” is suitable for use in zone 21, where explosive atmospheres caused by combustible dusts may be present.
If, depending on the manufacturer, the product has no marking, this may indicate that it is either not suitable for use in potentially explosive atmospheres or that it cannot ignite an explosive atmosphere and is therefore not covered by the ATEX directive. In such a case, the device is inherently explosion-proof.
What are Ex Zones?
Ex zones, also known as potentially explosive atmospheres, are special working environments or locations where there is a risk of an explosive atmosphere occurring. These explosive atmospheres can arise due to the presence of flammable substances such as dusts or liquids.
Ex zones are present in various applications, including oil and gas extraction, the chemical industry and many more. Compliance with regulations and safety measures in explosion-protected zones is crucial to making working environments safer and minimizing the risk of explosions.
The legal obligations include, among others:
- Labeling of Ex zones: Ex zones must be clearly marked as standard to alert employees and visitors to the risk of explosion.
- Avoidance of ignition sources: To minimize the risk of explosion, it is crucial to prevent or reduce all potential ignition sources in protected Ex zones.
- Measures to prevent explosions: Operators must take suitable measures to prevent a possible explosion or to limit its effects.
- Documentation of explosion protection: All relevant protective measures and safety precautions used to protect the potentially explosive areas are documented in an explosion protection document.
EX zone classification
The Ex zone classification refers to the classification of potentially explosive atmospheres into three main categories in accordance with the ATEX directives: Ex zone 0, Ex zone 1 and Ex zone 2. This classification greatly facilitates the use of suitable products and equipment in areas where there is a risk of explosion.
- Ex zone 0: In this zone, there is a continuous or prolonged explosive atmosphere generated by gases, vapors or mists. This atmosphere can occur during normal operation or occasionally. Special precautions are required due to the permanent risk of explosion in zone 0, for example from sparks.
- Ex zone 1: An explosive atmosphere may occasionally occur in this zone during normal operation. Compared to zone 0, the explosive atmosphere in zone 1 is less frequent and of shorter duration. These are areas in which a hazardous atmosphere can occur during normal operating conditions, for example in the event of leaks or faults.
- Ex zone 2: An explosive atmosphere rarely occurs in this zone and normally only for short periods. In general, these are areas in which a hazardous atmosphere is not to be expected during normal operating conditions or only for a short time.
Serafima: Ex fans and system components
If repairs are expensive or time-consuming, or if the requirements for your machines change – be it the material transported, the working conditions or safety standards such as ATEX – it may make sense to replace your old machines with new ones. This is where expert advice is crucial. At Serafima, we are at your side with our knowledge. We will discuss the options available and work with you to find the best solution for your needs.
Our experienced sales team will help you select machines and industrial fans for new projects or expansions, as well as with their procurement, installation and commissioning. We also offer comprehensive services for the serviced machines and are happy to support you with the procurement of spare parts.
With Serafima at your side, you can concentrate on your core business and benefit from our expertise in fans and compressors. Contact us now and we guarantee you a high level of expertise, quality and service at eye level.