Many high temperature fans and blowers support industrial operations by either circulating heated air or moving off-gasses during the manufacturing process. High temperature fans and blowers that aren’t properly designed or fabricated for this purpose will put your product at risk.
These fans can fail in several ways. However, they can be re-designed and fabricated for maximum performance and service life. Here are several factors that maintenance managers should consider.
Factor #1 – Materials Selection
Materials selection encompasses the material used to make the fan blade, the shaft and house the fan components.
Many fan designs do not take into consideration the exposure to harsh environments. A very common heat treatment is carburization of low carbon steels. Initially the part surface at 1,750 deg F is exposed to a carbon enriching atmosphere. It acquires a high carbon level to increase hardness and wear with the low carbon core having toughness when subsequently quenched. However, in the 800-1,200 deg F range there is a high opportunity for fan wheel metal dusting. Proper fan alloy selection is critical for performance life in this atmosphere type as well as aggressive chemical/thermal environments.
Fan blade distortion is going to happen no matter what, but proper design and material selection can help delay its effects.
Factor #2 – Fan Bearings
Most high heat fan shaft bearings can handle temperatures of 300 degrees Fahrenheit – temperatures above this can lead to immediate failure. Forced air and water cooling are two approaches to ensure bearings operate efficiently and effectively in high temperature furnace environments. While each option has their pros and cons depending on your manufacturing process, what’s most important to understand is that this is one key factor in the lifespan of your fan.
Factor #3 – Preventative Maintenance
Even during optimal operating conditions, high temperature fans likely need service or repair due to mechanical wear. During preventive maintenance, you’ll need to look for fan blade distortion and conduct a greasing and inspection of the bearings. Remember that fan refurbishment is possible when issues are identified and addressed early.
Your Next Steps
Keep in mind that it takes years of experience and mechanical aptitude to properly identify and diagnose the cause of some very subtle high temperature fan problems. Make sure you partner with a vendor that has expertise in process-design, high-temperature bearing selection and shaft-support-system design.
The lead time for a new fan can range anywhere from 8 to 16 weeks, so it’s important to begin understanding how and why your high temperature fan is failing and start the process of addressing the issues.
Alloy Engineering repairs high temperature fans and blowers in a variety designs and styles. To learn more, contact us here or call us at 440.243.6800.