Where Are Mobile Exproof Fans Used? Portable Hazardous-Area Ventilation
Where fixed ventilation is unavailable, or air exchange is required only during maintenance, cleaning or temporary operations, mobile exproof fans provide an important option. Portable construction combined with the correct ATEX suitability enables fast and flexible ventilation in the field.
What is a mobile exproof fan?
A mobile exproof fan is a fan system intended for temporary or portable ventilation duties in areas where an explosive-atmosphere risk may exist. It can be moved between work points without depending on a fixed fan station and, with suitable ducts or accessories, can support local extraction or air supply.
The main benefit of the mobile construction is flexibility. Maintenance teams can use the same fan at different work locations, supply air to a temporary work area or support controlled air exchange in an enclosed space.
Exproof suitability is independent of portability. The zone, gas/dust group, temperature class, electrical supply and certificate conditions must be suitable at every location where the fan is used.
Main areas of use
Mobile exproof fans can be considered particularly where fixed ventilation is impractical or where temporary operations are carried out:
- Controlled ventilation of tanks and certain enclosed spaces
- Temporary work areas using paint or solvents
- Maintenance operations in chemical and petrochemical facilities
- Suitable temporary applications in fuel storage or transfer areas
- Planned temporary ventilation while a fixed system is out of service
Confined-space work is not made safe by fan selection alone. Gas testing, permit-to-work, supervision, rescue/evacuation planning and other occupational-safety measures must be applied according to plant procedures. The fan is one item within that broader safety plan.
What information is needed when selecting the fan?
Mobile fan selection requires some additional inputs compared with a fixed installation. In addition to zone, gas/dust group, temperature class and ambient temperature, the way the fan will be connected at the work location should be described.
- Required airflow
- Flexible-duct diameter and total length
- Bends, adaptors and other fittings
- Extraction or supply-air scenario
- Electrical supply conditions and cable distance
- Transport and positioning constraints
Long or narrow flexible ducts can create substantial pressure loss. The free-air airflow shown in a catalogue may therefore be very different from the actual site airflow. Selection should take the complete system resistance into account.
Portable does not mean suitable everywhere
A common mistake with mobile equipment is to assume that a fan marked “exproof” can be used in every hazardous area. In reality, the product label and certificate scope must be checked again for each site.
Even if the fan itself is suitable, the system safety integrity can be compromised by an unsuitable extension cable, plug/socket arrangement, cable gland or other electrical accessory. The fan should likewise not be used with a damaged casing, loose guard or inappropriate mechanical modification.
Mobile equipment should be visually inspected after transport and the checks required by the site procedure should be completed before each use.
MOB-AXD/ATEX solution
The MOB-AXD/ATEX mobile exproof fan in the Vensis product range can be evaluated for suitable applications that require portable site ventilation. The correct model should be selected by considering the hazardous-area classification together with the required air performance, not by fan diameter alone.
A quotation request should ideally include the zone, gas group/temperature class, ambient temperature, required airflow, flexible-duct diameter and approximate duct length. This provides a stronger basis for model selection.
If the mobile fan will be moved between sites, the hazardous-area conditions at each new work point must be checked separately. Portability provides operational flexibility; it does not replace ATEX suitability.