UB 20xx – ex-proof ventilator

Special features in potentially explosive atmospheres

Installation conditions and the different hazardous areas must be observed; only connect the unit to explosion-protected mains sockets; ground antistatic hoses if necessary.

Fans for explosive atmospheres

Fans with ATEX approval may be operated in Zone 1 and 2.

Zone 1 is an area in which a hazardous explosive atmosphere consisting of a mixture of air and flammable gases, vapours or mists is likely to occur in normal operation occasionally. The equipment is approved for substance group IIB. A typical gas for group IIB is ethylene with an ignition energy of 60 – 180 mJ.

Ventilation of shafts

If the existing natural ventilation in shafts and duct systems is not sufficient due to local conditions such as the location of the shafts or their cover properties, additional, technical ventilation measures become necessary. Especially in warm temperatures, when the air in the manhole is cooler than that in the surrounding area, it is often not possible to provide sufficient ventilation. Even temporarily opening manhole covers is not always sufficient for optimal ventilation.

In sewer shafts, for example, foul gases can displace the oxygen in the air and thus lead to unconsciousness among sewer workers. This can be remedied with targeted technical ventilation and powerful fans. The fresh air then reaches the workplace directly and prevents health impairments caused by bad air.

Sufficient technical ventilation is achieved when, for example, an air flow of at least 600m³/h per m² of duct cross-section is achieved in ducts.