ATEX Fans And Potentially Explosive Environments | Puravent | Industrial

Explosion Proof ATEX Fans

What is often misunderstood is what exactly is a 'potentially explosive environment', and where would you actually need an ATEX fan in an explosive environement, compared to a fan not designed for these sorts of applications. Firstly, explosive atmospheres can be occur in environments where there are flammable gases, mists or vapours, or combustible dusts. With enough of one of these substances mixed with sufficient oxygen in the air, the result is potentially explosive, needing nothing more than the spark from an electric motor or closing switch to cause an explosion. The costs associated to such an occurrence can cause not only significant damage, but also serious injuries, or loss of life. Therefore, the need to prevent releases of certain dangerous substances which can create explosive atmospheres and the need to prevent sources of ignition, are two important ways to reduce the risk. This can be done by using the correct equipment and understanding the dangers and regulations associated. Equipment used in ATEX zoned areas is required to be suitably certified for use the that particular category of zone. Likewise fans used for moving air or for pneumatic conveyance of powers are no different and also need to be certified.

Looking to purchase an ATEX fan for your commercial premises? Click here to browse our range.

Explosive Environments and Regulations

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) outlines the required duties for employers to enforce in order to eliminate or control the risks from explosive atmospheres in the workplace.

DSEAR defines an area where an explosive atmosphere may occur that requires special precautions to protect the health and safety of workers and enivornment as hazardous. An area where an explosive atmosphere is not expected to occur in quantities that require such special precautions is deemed to be non-hazardous.

What is an Explosive Atmosphere?

According to DSEAR, an explosive atmosphere is identified as the mixture of dangerous substances (gases, vapours, mist or dust with air), under atmospheric conditions. With contact to ignition, combustion spreads to the entire unburned mixture and can result in explosion and harm to the workplace. These atmospheric conditions present are commonly referred to as 'ambient temperatures and pressures', which is temperatures of –20°C to 40°C and pressures of 0.8 to 1.1 bar.

Where can Explosive Atmospheres occur?

Work places which produces and store foodstuffs (flour, cereals, grains, etc.) such as (powder silos, warehouses);
Farms;
Painting workshops (including vehicle spray painting workshops);
Carpentry workshops;
Petrochemical plants;
Fuel, gas or solvent storage and handling facilites
Laboritories and research facilites
Energy production plants (power stations);
Pumping stations;
Holds of cargo ships;
Within big fuel tanks/ drums and road tankers;

Typical ATEX zoned area in powder handling facility

Petrochemical facilities are typically covered with ATEX gas zones.

Underground and surface mines.

Employers hold the responsibility to classify these potentially explosives areas into zones. DSEAR provides a ' formula' to the classification of each product. This can be broken down to see what environment the product is designed for. In regards to ATEX fans, the categories and ratings can be seen below. For further information on the protection ratings, refer to the 2002 Dangerous Substances and Explosive Atmospheres Regulations.

Identification for atex explosion proof fans

Zoning Definition and Equipment Suitability

Zone	Description	Equipment Suitability
0	A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is present continuously or for long periods or frequently.	1G
1	A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally.	2G
2	A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only.	3G
20	A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously, or for long periods or frequently.	1D
21	A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally.	2D
22	A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only.	3D

Types of Protection

Gas

Dust

TYPE	ATEX CODE	STANDARD
General Requirements	-	EN 60079-0
Intrinsic Saftey	Ex ia and ib	EN 60079-11
Increased Saftey	Ex e	EN 60079-7
Flameproof	Ex d	EN 60079-1
Pressurisation	Ex p	EN 60079-2
Powder FIlling	Ex q	EN 60079-5
Encapsulation	Ex ma and mb	EN 60079-18
Oil Immersion	Ex o	EN 60079-6
Type n	Ex n	EN 60079-15

TYPE	ATEX CODE	Standard
General Requirements	-	EN 61241-0:2006
Protection by Enclosures	tD	EN 61241-1:2004
Protection	pD	EN 61241-4:2006
Intrinsic Saftey	iD	EN 61241-11:2006
Encapsulation	mD	EN 61241-18:2004

Groups

I Electrical equipment intended for use in mines susceptible to firedamp~

II Electrical equipment intended for use in places with an explosive gas atmosphere other than group I

III Electrical equipment intended for use in places with an explosive dust atmosphere other than group I

Gas Group

IIA Propane
IIB Ethylene
IIC Hydrogen/ Acetylene

Dust Group

IIIA Combustible flyings
IIIB Non-conductive dust
IIIC Conductive dust

Level of Maximum Surface Temperature

T1 450°c
T2 300°c
T3 200°c
T4 135°c
T5 100°c
T6 85°c

With these ratings and categories in mind and when looking at certain ATEX explosion proof fans, it is easier to understand more about a product range and the ATEX zone type that the fan is certified and suited to.

Interested in the ATEX range?

Inline Ducted ATEX fans

KTEX

II 2G Ex e IIB + H² T3 Gb

(II) Suitable for common surface application
(2G) Suitable for zone 1
(Ex e) Increased saftey mechanisms
(IIB) Suited to applications with Ethylene
(H²) Also suitable for applications with Hydrogen
(T3) Max surface temperature of 200°c
(Gb) Gas equipment protection level

Roof EX fans

DVEX
II 2G c Ex e IIB T3

(II) Suitable for common surface application
(2G) Suitable for zone 1
(Ex e) Increased saftey mechanisms
(IIB) Suited to applications with Ethylene
(T3) Max surface temperature of 200°c

DVV-EX
II 2G c IIB T4

(II) Suitable for common surface application
(2G) Suitable for zone 1
(c) Increased constructional saftey mechanisms
(IIB) Suited to applications with Ethylene
(T4) Max surface temperature of 135°c

Medium Pressure Axial Fans

AXC-EX
II 2G c Ex d IIC T4 Gb

(II) Suitable for common surface application
(2G) Suitable for zone 1
(c) Increased constructional saftey mechanisms
(Ex d) Flameproof
(IIC) Suited to applications with Hydrogen and Acetylene
(T4) Max surface temperature of 135°c
(Gb) Gas equipment protection level

AXCBF-EX

II 2G c Ex de IIC T4 Gb

(II) Suitable for common surface application
(2G) Suitable for zone 1
(c) Increased constructional saftey mechanisms
(Ex de) Flameproof and increased saftey mechanisms
(IIC) Suited to applications with Hydrogen and Acetylene
(T4) Max surface temperature of 135°c
(Gb) Gas equipment protection level

Centrifugal Explosion Proof Fans

DKEX

II 2G 3G Ex e T1 T2 T3

(II) Suitable for common surface application
(2G and 3G) Suitable for zone 1 and zone 2
(Ex e) Increased saftey mechanisms
(T1, T2, T3) Max surface temperature of
either 450°c, 300°c, 200°c, respectively

II 2G 3G Ex de IIA IIB T1 T2 T3 Gb

(II) Suitable for common surface application
(2G and 3G) Suitable for zone 1 and zone 2
(Ex e) Flameproof and Increased saftey mechanisms
(IIA and IIB) Suited to applications with propane
and ethylene
(T1, T2, T3) Max surface temperature of either
450°c, 300°c, 200°c, respectively

Low Pressure Axial EX Fans

AW-EX
II 2G c Ex e IIB T4 T3

(II) Suitable for common surface application
(2G) Suitable for zone 1
(c) Increased constructional saftey mechanisms
(Ex e) Flameproof and Increased saftey mechanisms
(IIB) Suited to applications with ethylene
(T4 or T3) Max surface temperature of either
135°c, or 200°c, respectively

Plastic EX Fans

PRF-EX

II 2G c Ex e IIB T3

(II) Suitable for common surface application
(2G) Suitable for zone 1
(c) Increased constructional saftey mechanisms
(Ex e) Flameproof and Increased saftey mechanisms
(IIB) Suited to applications with ethylene
(T3) Max surface temperature of 200°c

RVK-EX
II 3G Ex d IIB T4

(II) Suitable for common surface application
(3G) Suitable for zone 2
(Ex d) Flameproof
(IIB) Suited to applications with Ethylene
(T4) Max surface temperature of 135°c

For further information on ATEX clasifications or products on the Puravent range including ATEX heaters, please visit the Puravent w ebsite.Or email further enquiries at [email protected]

Heat Load	Watts	BTU
Average The Room Is A Normal Residential Room, Office, Reception Area Or Similar, Where There Is Not Overly Crowded With People, Computer And Office Equipment.
Above Average There Are Factors That Contribute To Additional Heat Being Generated In The Room E.G. Strong Lighting, Overcrowding With People And Office Equipment, Conservatory Type Room, Or Flat Roofed Room.
High There Are Factors That Contribute To A High Heat Load In The Room. E.G. Commercial Cooking, Much Computer And Server Equipment, Switchgear, Temporary Building With Thin Walls And Flat Room, Plain Glass Conservatory.

Variable	Units	Notes/Guidance
System Airflow	M3/Hr	If you have it in cfm then multiply your cfm value by 1.7 to get m3/hr
Average Combined Pressure Drop Of Filters Of Higher Than F6 Efficiency	Pascals	F8 bag filters pressure drop - typical clean clean to dirty, 160 - 250 Pascals F9 compact filters pressure drop - typical clean to dirty, 160 - 350 Pascals H10 HEPA filter pressure drop - typical clean to dirty, 250 - 600 Pascals 9.8 Pascals = 1 mm wg, & 249 Pascals = 1 inch wg
Carbon Filters Pressure Drop	Pascals	For compact type carbons pressure drop between 100 - 150 Pa Bonded carbon panels typically 150 - 170 Pa Loose granular carbon panels typically 130 Pa
Annual Operational Hours	Hrs/Annum	8760 hours in a year If operating for 5 days a week, excluding public holidays, for 12 hrs/day = 3000 hrs
Cost Of Power	Pence Per Kwh	Huge variance in what different companies pay. heck your last bill to be sure, otherwise put in 10p
Fan Efficiency	(As Decimal Value, Eg 100%=1)	Would typically be around 60%, so if you don’t have specific information use 0.6
Fan Motor Efficiency	(As Decimal Value, Eg 100%=1)	Larger motors should be around 90%, so if you don’t have specific information use 0.9

The Total Average Pressure Drop Over Your Higher Efficiency Filters And/Or Carbon Filters Is;		Pascals
This Pressure Drop Is Costing In Energy Alone	£	Per year
It Is Probable That A Sanuvox In-Duct System Could Break Down The Biological, Chemical And Odourous Contaminants On This Air Flow For Between 16 And 25% Of This Running Cost	£	Lower energy cost estimate of an equivalent Sanuvox system (16%)
	£	Higher energy cost estimate of an equivalent Sanuvox system (25%)

Type Of Building	Kw Range		BTU Range
Sports Centres
Retail Premises
Office Premises
Small Industrial Unit
Medium Industrial Units
Larger Industrial Buildings
School/Community Halls
Churches

Room/building volume	m3
Temperature differential (deltaT °C)	°C

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ATEX Fans and Explosive Environments

Explosion Proof ATEX Fans

Explosive Environments and Regulations