Industrial exhaust fans for the oil & gas industry: petrochemicals

05 September 2022

The explosive and corrosive nature of petrochemical productions means that industrial fans must meet specific criteria to ensure they operate safely and effectively. As an ATEX and corrosion resistant fans expert, Axair Fans regularly speaks to contractors, installers and consultants operating in the oil and gas industry including those that are involved in the ventilation and exhaust systems to safely operate petrochemical processes.

Petrochemicals are chemicals made from petroleum, crude oil and natural gas - the primary and raw material sources that enable numerous aspects of modern daily life and the world economy. Petrochemicals are the intermediate, or by products, of refining these gases or oils. They’re used to produce everyday goods such as plastics, cosmetics, tyres, resins, rubbers, adhesives, and even embalming substances. Without the production of these petrochemicals, life would be very different.

There are obviously environmental disadvantages of petrochemical processes; the sheer amount of toxic waste, VOC’s, global warming potential and air pollution to name a few, but that’s one for someone else to discuss.

Petrochemical plants convert the raw materials crude oil and natural gas into chemical products such as ethylene, propylene, xylene, and methanol with a series of high-tech separation processes. During these high temperature and intensive processes of separation, exhaust streams produce potentially hazardous and corrosive chemical and gas residues that require protective and highly corrosion proof exhaust systems to ensure they’re working safely.

From experience, our customers choose explosion proof ATEX exhaust fans for use within petrochemical works. Exhaust fans safely remove and transport the hazardous gases away from personnel and prevent these gases from mixing with other elements to avoid explosions.

What is meant by ATEX?
ATEX stands for atmospheres explosible and refers to an area where there is a potential for an explosion if there is the presence of combustible dust or gases. The potential for the explosion is separated by what is known as gas and dust zones. The more likely an explosion the lower the number related to the zone. For example, zone 0 gas area classification means that an explosion potential is continuously present, zone 2 would mean the explosion potential may occur abnormally and with zone 1 it would occasionally be present. This dictates the type or equipment and the protection rating required to ensure continual safety. The same idea is in place for combustible dusts with zone 20, 21 and 22. You can learn more about ATEX gas and dust zones here. Axair don’t supply products that sit within zone 0 ATEX applications across any of our explosion proof ranges.

Choosing a Suitable Petrochemical Exhaust Fan
Choosing an ATEX approved fan that can handle both the extreme temperatures of the fracking process but also resist any corrosive gases that may destroy internal or whole fan components is the preferred choice. Therefore 304 stainless steel ATEX fans are an ideal choice. 304 stainless steel fans are available in two constructions. Either only the internal components are manufactured using stainless steel, if it is only these parts that will be present in the corrosive air, or alternatively, if the entire fan is situated in a corrosive environment and is at risk of rusting as a result, then the entire outer casing and internal components can be manufactured from corrosion resistant materials while still having explosion protection up to zone 1 gases.

ATEX Temperatures Classes in Petrochemical
Choosing to protect against corrosion is easy enough once you know the chemicals present but what about extreme high temperatures? There are a huge number of processes involved in petrochemical production. The distillation of crude oil which contains a mixture of hundreds of hydrocarbons involves heating in a furnace and the resulting mixture is fed as a vapour into a distillation tower. The chemicals produced have different temperatures that separate them during the fractional distillation stage creating a temperature gradient in the tower ranging from high <350°C to 25°C. Following the distillation step, cracking (steam or catalytic) is the main process that breaks these mixtures down into hydrocarbons by means of high temperatures and pressure. Hydrocarbons are generally flammable, so it is compulsory that ATEX explosion proof exhaust fans are used in machines or plants in the chemical industry. Generally, wherever air is contaminated with flammable substances then there is a need for protection.

Industrial fans are temperature rated to ensure that they’re not used in an environment that would exceed the highest acceptable surface temperature on the fan motors surface. If the temperature on the surface of the motor exceeds this level, ignition of either the gas or dust is possible. This is a required indication that the customer should communicate before we can select an industrial fan for any explosive environment. Hot surfaces become dangerous around 135°C. Temperature charts are useful in determining the correct T class based on chemicals in the air stream. For example, Hydrogen is a IIC Gas group with a T temp class making it one of the hottest, most dangerous gases. Learn more about ATEX temperature classes here.

Safe Exhaust in the Oil & Gas Industry
In the oil and gas industry, industrial exhaust fans are designed for corrosion protection, explosion protection and protection against other elements such as heat, moisture, and salty air. Our AC Casals industrial fans are built for use In the oil and gas sectors due to their high load capacity, high carried air temperature, their ability to withstand contaminated or chemical air easily without disruption to their function and they’re easy to maintain.

Talk to an experienced member of the Axair Fans industrial team on 01782 349 430 or email sales@axair-fans.co.uk to discuss your industrial fan requirements if operating in any area of contaminated air or explosive environment.

Axair Fans UK Limited
www.axair-fans.co.uk