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Cooling Tower Thermal and Structural Specialists

Vibration, Balance Testing and Evaluation

Mechanical draft cooling towers use rotating equipment in the form of motors, drive shafts, gear speed reducers and fans.  All of this must be properly balanced or the cooling tower vibration may be objectionable.  Cooling tower vibration testing at very low frequency, such as the rotation frequency of a large fan, requires the use of special low frequency equipment.  If the fans are driven by variable frequency drives, fan speeds which cause resonant frequency vibrations must be determined and blocked out.  Excessive low frequency cooling tower vibration can damage the structure of cooling towers.  Vibration at motor speed may be an indication of the failure of drive shaft couplings.  If the coupling on either end of the drive shaft fails, the shaft can come in contact with the fan blades causing severe damage to the fan, fan cylinder and tower structure.  Cooling tower vibration at other frequencies may indicate problems with bearings or gears.