An ATEX fan is equipment manufactured to the category defined by explosive atmosphere regulations and delivered with the certification for that category. The name comes from the abbreviation of the European Union directive, and the same principles are in force in T\u00fcrkiye.<\/p>\n
A common mistake in the market is to treat any fan with an explosion-protected motor as an ATEX fan. The certification covers the entire fan, meaning the impeller, housing, shaft, bearings and motor are assessed as a whole. A unit with a suitable motor but a standard impeller falls outside this scope. This technical file is also the first document requested during an inspection.<\/p>\n
In terms of moving air, the operating logic is no different from a standard fan. The impeller rotates and air is moved by centrifugal or axial force. The difference is that every source that could lead to ignition is eliminated by design.<\/p>\n
There are three sources of risk. The first is friction sparks caused by the rotating impeller contacting the housing, the second is temperature rise caused by dust accumulating on surfaces, and the third is static electricity. In explosion proof fan design, a calculated clearance is left between the impeller and the housing, all metal parts are grounded and the surface temperature is kept below the ignition temperature of the surrounding atmosphere.<\/p>\n
ATEX fan features consist of technical decisions reflected in the certification. Each one is determined according to the zone classification.<\/p>\n
The relevant design standard defines the clearance between impeller and housing as a ratio linked to the impeller diameter and does not allow it to fall below a minimum limit. This clearance slightly reduces fan efficiency, but in return it eliminates the risk of contact.<\/p>\n
Types differ by both zone category and housing design. The zone classification determines which category is required.<\/p>\n
| \n Zone<\/p>\n<\/th>\n | \n Atmosphere<\/p>\n<\/th>\n | \n Duration of Explosive Atmosphere<\/p>\n<\/th>\n | \n Required Category<\/p>\n<\/th>\n<\/tr>\n |
|---|---|---|---|
| \n Zone 20<\/p>\n<\/td>\n | \n Combustible dust<\/p>\n<\/td>\n | \n Continuously or for long periods<\/p>\n<\/td>\n | \n 1D<\/p>\n<\/td>\n<\/tr>\n |
| \n Zone 21<\/p>\n<\/td>\n | \n Combustible dust<\/p>\n<\/td>\n | \n Occasionally in normal operation<\/p>\n<\/td>\n | \n 2D<\/p>\n<\/td>\n<\/tr>\n |
| \n Zone 22<\/p>\n<\/td>\n | \n Combustible dust<\/p>\n<\/td>\n | \n Rarely and for short periods<\/p>\n<\/td>\n | \n 3D<\/p>\n<\/td>\n<\/tr>\n |
| \n Zone 1<\/p>\n<\/td>\n | \n Gas and vapor<\/p>\n<\/td>\n | \n Occasionally in normal operation<\/p>\n<\/td>\n | \n 2G<\/p>\n<\/td>\n<\/tr>\n |
| \n Zone 2<\/p>\n<\/td>\n | \n Gas and vapor<\/p>\n<\/td>\n | \n Rarely and for short periods<\/p>\n<\/td>\n | \n 3G<\/p>\n<\/td>\n<\/tr>\n<\/table>\n<\/div>\n By housing design, the classification is the same as for standard fan groups. Straight-bladed radial types are used on dust-carrying lines, axial types for area ventilation and spiral-housing scroll fan designs on mixed lines. The zone category does not change which housing is chosen; it only determines how that housing is built.<\/p>\n ATEX Explosion Proof Fans<\/h3>\nThe ATEX explosion proof fan is the type built for lines where both the internal and the external atmosphere are classified. The air-handling side of the fan and the motor side are certified separately.<\/p>\n In dust extraction lines, the inside is usually classified as Zone 21 or Zone 22, while the outside is considered unclassified. When ordering an ATEX explosion proof fan, these two values must be stated separately; otherwise the unit is built to a higher category than necessary and the cost rises needlessly.<\/p>\n Explosion Proof Radial Fans<\/h3>\nBecause the explosion proof radial fan runs with a straight-bladed impeller, it does not accumulate dust and prevents surface temperature rise from the outset. This group is the first choice for lines carrying combustible dust.<\/p>\n For materials such as wood dust, starch, sugar dust and aluminum dust, the absence of build-up on the impeller is decisive. The difference from a standard radial fan is not the blade geometry but the discipline applied to clearance, materials and grounding.<\/p>\n Explosion Proof Axial Fans<\/h3>\nThe explosion proof axial fan moves high airflow at low pressure, so it is used for area ventilation and gas dilution. It is preferred when the duct run is short.<\/p>\n Paint booths, battery charging rooms, chemical stores and areas where solvents are used are the domain of this group. An explosion proof axial fan is insufficient on its own on dusty lines, because its blade design cannot handle filter resistance.<\/p>\n ATEX Fan Applications<\/h2>\nIf a facility contains combustible dust or vapor, a hazardous area classification must already be in place. Fan selection is an output of this map, because two sections of the same facility may require different categories.<\/p>\n
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