Air coolers for refinery services troubleshooting

[sinectica]

Does anybody know where can I find information about vibration analysis and troubleshooting for air coolers for refinery services?
I suspect that I have some structural problems in some big fan coolers and I don't have a clear idea of how to solve them.
I've checked API STD 661 but it doesn't say so much.

Thanks so much
Marc

 

[zqew05]

Our pillow block bearings have been failing more on our HAMMCO coolers. It started when we increased the pitch to our cooling fan blades to increase flowthru.

 

[FERNENG]

Is this a new problem or has it existed for some time? If the problem is recent I would look for changes. Something as simple as debris building up on the fan blades could cause a vibration.

 

[zqew05]

It has been running for three years before we have to replace the bearings, but now it has been more frequent. It is a compromise between less cooling efficiency and bearing reliability. We're thinking of installing a newfangled eductor type funnel on the exhaust side of the cooler. Hopefully it increases cooling efficiency without having a sharp pitch angle on the blades