Occasionally, centrifugal fans can experience problems that may eventually lead to fan failure. To prevent fan failure, it is important to know the warning signs of problems with your centrifugal fan. In my blog this week, I will discuss the two warning signs of a problem with your centrifugal fan.
Noise
Excessive noise is a warning sign of a centrifugal fan problem. The most common cause is the wheel coming in contact with the inlet or housing. The problem could be damage or misalignment of the inlet or housing. Excessive noise may also be caused by a bent or broken wheel. Additionally, a loose or misaligned shaft or bearing may also contribute to excessive noise. Other factors such as build-up of dirt and oil or lack of lubrication can also contribute to excessive noise. Even obstructions and leaks in the ductwork can cause noise.
On the other hand, if your centrifugal fan is not producing enough noise, it could be a sign of an underlying electrical or mechanical issue. Potential problems such as blown fuses, loose pulleys or belts, and seized bearings could be responsible for a fan that is not operating correctly and is unusually quiet.
Vibration
A vibrating centrifugal fan is another warning sign of a problem. Many of the issues that cause excessive noise will also cause vibration. Another problem that can cause vibration is the fan operating in the unstable region of the fan curve. Any changes to process ductwork, such as adding a pick-up point or damper, will change the operating point of the fan which may push it into the unstable region.
A centrifugal fan operating at its resonant frequency will vibrate. The way to check for this is to use a VFD to slow down the fan until it no longer vibrates.
Conclusion
Don’t ignore the warning signs of a problem with your centrifugal fan. The longer the problem goes unresolved the higher the potential for damage to the fan. If you need help trouble shooting your centrifugal fan problem, contact a ventilation expert at Eldridge. Along with our centrifugal fan partner Industrial Air Products, we will find the problem and recommend solutions to get your centrifugal fan back in top operating condition.