Our plant has urgently requested that the main fan be disconnected from the flue gas extractor; the vibration of the fan during the operation of Unit 3 is 6–7 microns higher than that during the operation of Unit 4
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Due to scaling on the smoke exhaust fans in our plant, it is necessary to carry out maintenance on them. At present, three units are in operation; however, the vibration levels of these fans are slightly higher than usual, but the overall trend remains stable. Why is this happening? Could everyone please help analyze it?
We have never operated the fan separately; whenever we clean the smoke extractor, we run the backup unit instead
Flow rate, pressure, temperature, and resonance between devices all have an impact, in addition to individual factors.
Could it be related to the power balance between the shaft systems? Previously, both the smoke extractor and the turbine drove the fan
If it can be considered acceptable as long as it’s within the limits, then that’s fine, because there are too many factors that contribute to this. This has to be gradually explored and understood over the course of long-term production. Also, if the problem persists during testing and is an inherent issue, then it is a design problem. If it occurs later on, then the issue needs to be traced back to factors related to the equipment itself, such as imbalance or resonance caused by a loose bolt, etc. It is recommended to tighten the bolts in all areas, including the foundation bolts.
If the temperature of the hydrodynamic bearing does not change, it is basically due to an imbalance in the rotor
Have the maintenance company conduct an online check to see what issues exist
Large catalytic systems usually don’t have a backup unit; if there’s a problem with the exhaust fan, the main unit is used directly