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ATEX fans - an explosive issue A
TEX is an acronym derived from the French expression ATmosphères EXplosibles and exists in the form of two European directives
for controlling explosive atmospheres. The fi rst ‘equipment directive’ 94/9/EC (ATEX 100) covers manufacturing standards. The second ‘workplace directive’ ATEX 99/92/EC (ATEX 137) seeks to ensure that people are protected against the risk of blast injuries or asphyxiation by dangerous substances. The 2016 updated legislation is Directive 2014/34/EU and assists with establishing a uniformity to the approach taken when supplying and distributing equipment such as industrial fans for explosive atmospheres. Everyone involved in the specifi cation, manufacture,
installation, and use of equipment in fl ameproof zones has some responsibility in ensuring that the law concerning fl ameproof equipment is upheld. Unfortunately, a lack of
practice with the subject tends to give rise to enquiries that begin with statements like “there
is a slight risk of explosion, but we don’t think we need a fl ameproof fan” which places manufacturers in an awkward position because they are not ATEX consultants and are not qualifi ed to know what the client can lawfully install. What can the fan supplier do with casual enquiries that must at some point turn into tightly specifi ed orders? The fi rst option is a blunt “come back when you know exactly what is required” and the second is to issue a questionnaire, usually with ‘tick boxes” and a bit of guidance appended, which may then be returned with confl icting selections. What is needed in every case is an ATEX code that
provides a well-defi ned minimum standard for the product that is required. For example, the code Ex II 2G IIC T4 essentially means European fl ameproof, surface industry (not mining), Category 2 (Zone 1), gas group II, type C (hydrogen or acetylene gas), maximum surface temperature 135˚C. There are many other coding permutations including slightly diff erent formats for dusty atmospheres (Zones 21 & 22). If codes cannot be provided there is uncertainty over what is required. Once an ATEX code has been established the process of selecting a fan model and its essential
Fans
Outside of major users such as chemical, petrochemical and process industries, enquiries for fl ameproof fans tend to come from specifi ers, resellers and end-users, many of whom may not be aware of ATEX Directives
features demands a degree of application knowledge. For example, the type of electrical supply is important. Often the response to “what electrical supply do you have” is “can be single or three phase”. Single phase is an expensive option and not widely available from ATEX motor manufacturers. It may be cheaper to run a 3~ line than to buy a 1~ fan on a long manufacturing lead-time. Any fan motor that is to be speed controlled with
a VSD must also have thermistors fi tted to protect against motor shell temperature at low speeds causing spontaneous gas combustion. By not mentioning the VSD aspect at the enquiry or order stage the purchaser is likely to ultimately face time and product replacement costs. Other matters include motors that vary from the most secure specifi cation EEx d (explosion proof) through EEx e (increased safety), down to EEx nA (non- sparking) which has many similarities to a standard non-fl ameproof motor. ATEX must be understood as being an ever-evolving subject requiring competence and training. Anyone requiring a better understanding of fl ameproof requirements would be advised to contact an expert.
Nicotra Gebhardt reaches 100,000 milestone with DDMP product range
Leading high effi ciency fan manufacturer Nicotra Gebhardt has reached a signifi cant milestone with the 100,000th of its DDMP range of EC direct driven forward curved centrifugal fans to roll off the production line.
S
ince the DDMP range was introduced, the average lead time from order to dispatch has been just ten days and that continues even in
these challenging times. The range’s high effi ciency EC-motor to IE5 standard operates without slip losses and consumes signifi cantly less power than conventional AC motors typically used for forward curved blowers, even in partial-load operation, giving a signifi cantly higher level of total system effi ciency. The range has now been extended with a
high-power 5.5kW motor and larger fan sizes up to 18/18
The DDMP range provides: • New high effi ciency EC-motor • Compact, symmetrical and streamlined motor design
• Obstruction-free inlet design, meaning signifi cantly less aerodynamic losses
• Sensor-less control • IP 54 performance • Analogue interface for speed control • Modbus compatible • Low sound level • Metric and imperial sizes range available • Interchangeable replacement for older ineffi cient AC fans in OEM products
• Perfect for retrofi t in in-situ equipment For more information email:
uk.sales@
nicotra-gebhardt.com
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April 2022
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