Balancing fans/ventilators

[Translate to EU/EN:] Lüfter auswuchten

Problem

Unbalances can occur on fans and ventilators in the course of maintenance work or due to product adhesions or contamination. These lead to an increased bearing load and thus to damage to rolling bearings.

Solution

Example

During a regular measurement, the fan for ventilation of a rotary kiln was examined. The 900 mm rotor was driven by a 143 kW electric motor. At an operating speed of 3000 rpm, a vibration velocity (10 ... 1000 Hz) of 3.6 mm/s was determined with the InnoMeter software module (numerical display). Of these, 3.5 mm/s can be assigned to the 1st order, i.e. to unbalance-related vibrations. To reduce the vibrations of the 1st order, an operational balancing was carried out. Due to the narrow fan geometry, balancing in 1 plane is sufficient.

Following the initial run, a test mass of 18 g was set to determine the influence of mass changes on the rotor.  After the test run, the InnoBalancer balancing module calculated a required correction of 33.8 g at 223°.

The correction masses mounted were able to reduce the vibrations caused by the unbalance to 0.16 mm/s. The result was a balance of 0.8 g at 223°. This corresponds to a reduction of 95 %.