Difference between explosion-proof fans and ordinary fans in Zone 0
Thread Content
This post was last edited by penryn on 2015-11-15 at 10:34. I would like to know what the difference is between explosion-proof fans and ordinary fans in zone 0 – is it related to the sealing performance? Additionally, explosion-proof fans have two flame arrestors at their inlet and outlet to prevent deflagration. The conveying medium is an explosive gas, an oxygen-containing combustible gas. I’m not sure what the differences are in terms of mechanical structure compared to ordinary fans. From what I know about some manufacturers, companies like Germany’s FIMA and Switzerland’s Meidinger charge exorbitant prices; for example, a Class 0 fan with a capacity of several hundred cubic feet and a pressure of dozens of kilopascals can cost hundreds of thousands of dollars from Meidinger. It seems no one has answered? ? ? ?
It must be more expensive; Zone 0 is the highest level of explosion hazard zone, and it requires the highest standards for equipment as well. There are requirements regarding material selection, fan clearance, and parameter monitoring, and these apply not only to the machine head but also to all associated components, such as motors and instruments, which must be explosion-proof. Furthermore, all equipment used in explosive areas must have explosion-proof certification. These are all costs. Ordinary fans simply cannot be used in this context; it’s like hitting someone while driving – if one has a driver’s license, it’s an accident, but if they don’t have one, the situation is completely different.
Thank you. Electrical explosion protection is something that is quite common; what I mainly want to know are the differences in the design of the fan itself, such as material selection, impeller processing, and the treatment of the flow channels, as well as issues related to frictional static electricity during flow. There might also be differences in sealing methods, shaft design, and other aspects of the design process.
It varies from one company to another; the only standard that requires explosion protection for non-electrical equipment is the ATEX directive. This is a European legislative requirement that is mandatory, aiming to ensure compliance with certain standards, but it is not compulsory to use a specific standard. In other words, as long as the result is achieved, there can be various methods; whether it is actually accomplished requires assessment by professional institutions. Therefore, when designing each product, the standards that need to be met can vary; for example, the gaps may differ slightly between Standard A and Standard B, but they all remain within the range required by the regulations, so there is no problem with that. And this is a design issue. So this issue needs to be discussed with senior supplier engineers, and the results you get may vary as well. But I think this is not decisive; what is decisive is the ultimate requirement of the instruction. I am a German equipment supplier, but I can’t give you a universal answer either. Moreover, I may not be aware of all the specific design standards, but the explosion-proof requirements for each area are clear to us.
The structural differences are minimal; of course, the materials used need to be special. Explosion protection for fans in the United States generally involves eliminating sparks, which leads to the use of non-ferrous materials. Europe seems to focus more on the overall system; for example, there are oxygen sensors that trigger an alarm or shut down the system before the oxygen concentration reaches critical levels, as well as the flame arrestors you mentioned. Moreover, their entire product range is ATEX-certified, so the price can’t be low – after all, only a few companies are capable of producing it.