Colombia. Glaciar Ingeniería shared an analysis of the dynamic imbalance in cooling tower fans, which is generated when the center of gravity and rotation do not coincide, causing vibration influenced by the environment and the speed of operation of the fan.
In a balance there is balance if on both sides we have the same weight. In the same way you have to imagine the distribution of the weight of a rotor with respect to its axis of rotation. If the weight is not distributed equally, we speak of imbalance.
Types of dynamic imbalance
- Static
- At the moment
- Dynamic
It is important to identify the presence of an imbalance outside the permissible ranges, since this produces an increase in vibration amplitudes in rotating machines, which is proportional to the speed of rotation. If the force is of considerable magnitude, the service life of the bearings and/or hydrodynamic bearings of the cooling towers can be reduced, which in turn can affect the additional increase in vibration.
When two unbalanced masses act on a rotating body, their respective disturbing forces appear.
Causes
- Mechanical or thermal distortion
- Assembly errors
- Eccentric components
- Corrosion and wear
- Broken components
With the roll, the forces generating vibrational disturbances are corrected or reduced.
The stresses on the frame of a mechanism, or on the supports, can vary significantly during a complete cycle of operation and cause vibrations that, many times, can reach dangerous amplitudes, that is, in unacceptable ranges.
Shelf life: unbalanced products = shorter life.
Safety: The vibrations loosen screws and nuts, until the fixings are released; switches and electrical connections can be damaged.
"Dynamic imbalance negatively influences performance."
