Explosion proof fans

ATEX fans for explosive atmospheres, or explosion-proof fans

PRINCIPLE

ATEX is the commonly used name of Directive 94/9/EC, which entered into force on 1 July 2003 (“ATmosphère EXplosive”) and was later replaced by Directive 2014/34/EU.

An explosive atmosphere is defined as a mixture of air and flammable gases, vapours, fumes or dusts, in which combustion, once ignited under atmospheric conditions, spreads very rapidly (explosion).

The scope of the ATEX Directive covers all equipment intended for installation in potentially explosive atmospheres, such as:

petrochemical plants
food processing facilities
power plants
woodworking workshops
paint spray booths
farms and greenhouses

Depending on the type of hazardous substance, explosive atmospheres are classified as:

G – gases
D – dusts
H₂ – hydrogen

The user or designer is responsible for performing hazardous area classification in accordance with Directive 1999/92/EC.

SOLUTION

An explosion risk assessment must be carried out within the facility or site in order to identify areas where explosive atmospheres may occur. Measures must also be defined to prevent or reduce such risks.

By using forced ventilation it is possible to:

reduce the size of hazardous zones, sometimes to a practically negligible volume
shorten the duration of the explosive atmosphere after emission stops
prevent the formation of an explosive atmosphere by diluting the flammable substance in air below the lower explosive limit in the immediate vicinity of the equipment

The ATEX Directive defines equipment classification criteria according to the required level of protection. The relationship between zone classification according to Directive 1999/92/EC and the applicable equipment protection category is shown in the relevant table.

Protection level	Equipment category (gases)	Zone of use (gases)	Equipment category (dusts)	Zone of use (dusts)	Hazard level of operating zone	In our product range
Very high	1G	Zone 0	1D	Zone 20	Explosive atmosphere is always present	No
High	2G	Zone 1	2D	Zone 21	Explosive atmosphere is likely	Yes
Normal	3G	Zone 2	3D	Zone 22	Explosive atmosphere is unlikely	Yes

Note: Equipment of a higher category may be installed in place of equipment of a lower category.

The Directive also defines European notified bodies authorised to inspect and assess technical documentation and to issue type-examination certificates for equipment intended for use in explosive atmospheres.

ATEX-compliant Maico Italia products are marked accordingly.

Table No. 1
ATEX installation zone	Zone 1 / 21 / 2 / 22
ATEX zone inside the fan	Zone 1 / 21 / 2 / 22
Equipment group	II
Equipment category	2G / 2D / 3G / 3D
Equipment Protection Level (EPL)	b / c
Electric motor protection type	Ex-d Gb / Ex-de Gb / Ex-e Gb / Ex-nA Gc / Ex-tb Db / Ex-tc Dc
Gas temperature class	T3 / T4 / T5 / T6
Gas group	IIA / IIB / IIB + H₂
Dust group	IIIA / IIIB / IIIC
IP protection class	IP55 / IP64 / IP65 / IP66
Standard temperature range	–20 °C / +60 °C (–40 °C on special request)
Notified body	IMQ (0051) / TÜV NORD (0044) / TÜV SÜD (0123) / TÜV AUSTRIA (0408) / BV/EPS (2004)

Table No. 2
ATEX installation zone	Zone 2 / 22
ATEX zone inside the fan	Zone 2 / 22
Equipment group	II
Equipment category	3G / 3D
Equipment Protection Level (EPL)	b / c
Electric motor protection type	Ex-d Gb / Ex-de Gb / Ex-e Gb / Ex-nA Gc / Ex-tb Db / Ex-tc Dc
Gas temperature class	T3 / T4 / T5 / T6
Gas group	IIA / IIB / IIB + H₂
Dust group	IIIA / IIIB / IIIC
IP protection class	IP55 / IP65
Standard temperature range	–20 °C / +40 °C

1 ATEX SCHEME

The following product range is ATEX certified by IMQ according to EN 14986:2017 and supplied in the following configurations:

H₂ – Hydrogen – Zone 1 II 2G Ex IIB + H₂ T4 Gb
G – Gases – Zone 1 II 2G Ex h IIB T4 Gb
D – Dusts – Zone 21 II 2D Ex h IIIB T135 °C Db

Models:

QCM ATEX – explosion-proof ATEX axial fans up to 17500 m³/h
CC ATEX – explosion-proof ATEX axial inline fans up to 142000 m³/h
FCP ATEX – explosion-proof ATEX roof centrifugal fans with horizontal discharge up to 30000 m³/h
FCP-V ATEX – explosion-proof ATEX roof centrifugal fans with vertical discharge up to 30000 m³/h
DIC ATEX – explosion-proof ATEX centrifugal fans up to 2400 m³/h
DIC INOX ATEX – explosion-proof ATEX centrifugal fans with stainless steel casing and impeller (AISI 304 or AISI 316L) up to 2400 m³/h
AL ATEX – explosion-proof ATEX centrifugal fans up to 11200 m³/h

Full classification is provided in Table No. 1.

Special versions on request:

60 Hz versions
Temperature classes T5 and T6

2 ATEX SCHEME

The following product range complies with ATEX requirements according to EN 14986:2017 and is supplied in the following configurations:

G – gases – Zone 2 II 3G Ex h IIB T4 Gc
D – dusts – Zone 22 II 3D Ex h IIIB T135 °C Dc

Models:

BOX-T ATEX – explosion-proof ATEX boxed centrifugal fans with forward-curved impeller and belt drive up to 30000 m³/h
BOX-T BC ATEX – explosion-proof ATEX boxed centrifugal fans with backward-curved impeller and belt drive up to 30000 m³/h

Full classification is provided in Table No. 2.

3 ATEX / IECEx SCHEME

The following product range is ATEX certified by TÜV Austria and tested and approved according to the IECEx scheme, applying the ignition protection concept.

Configurations:

H₂ – hydrogen / G – gases – Ex eb IIB+H₂ T3 Gb / Ex h IIB+H₂ T3 Gb
D – dusts – Ex tb IIIB T135 °C Db IP64X / Ex h IIIB T135 °C Db X

Models:

DZQ Ex – explosion-proof ATEX axial fans up to 9450 m³/h
DZR Ex – explosion-proof ATEX axial inline fans up to 9370 m³/h
DZD Ex – explosion-proof ATEX roof centrifugal fans up to 6510 m³/h
ERM Ex – explosion-proof ATEX mixed-flow fans up to 900 m³/h

4 ATEX SCHEME – Heavy-duty and special-purpose ATEX fans

ATEX certified by TÜV NORD according to EN 14986:2017, suitable for installation in Zones 1 / 21.

Models:

PR-L ATEX – high-capacity, medium-pressure centrifugal fans for lightly dusty air up to 140000 m³/h
PN-L ATEX – medium-capacity, medium-pressure centrifugal fans up to 32400 m³/h
PS-L ATEX – medium-high capacity centrifugal fans for heavily dusty air up to 98400 m³/h
PR-F ATEX – medium-high capacity centrifugal fans for dusty air up to 110000 m³/h
PQ-L ATEX – medium-capacity, medium-high pressure centrifugal fans up to 79200 m³/h
PY-L ATEX – low-medium capacity, high-pressure centrifugal fans for dusty air and pneumatic conveying up to 9000 m³/h
PV-L ATEX – low-medium capacity, high-pressure centrifugal fans up to 33000 m³/h

5 ATEX SCHEME

Compliant with EN 14986:2017, suitable for Zones 2 / 22.

Models:

PR-AC ATEX – centrifugal fans with polypropylene casing and impeller for chemically aggressive gases up to 17500 m³/h
ICA ATEX – centrifugal fans with polypropylene casing and impeller for chemically aggressive gases up to 7100 m³/h

Detailed information about ATEX fans, their fields of application, marking and installation examples is provided here: ATEX explosion-proof fan guide