Client: Yashili New Zealand
Location: Pokeno Dairy Factory
Scope of Work: Vibration Investigation
Date: July 2017

AEG was asked to investigate two identically designed bulk fans onsite. One of the fans had been observed to be vibrating at much higher levels than it's twin with no apparent reason for the difference.

Vibration data was measured using Pruftechnik VIBXPERT II portable analyser. Measurement data was taken from various points on the machine. Through a series of tests, including variable flow rates, a better understanding of the vibration was developed.

It was found that the probematic fan suffered from resonance at a specific flow rate. The resonance was associated with surrounding pipework. Additionally, low level indications of loosness in the fan drive end bearing were observed. AEG was able to identify an optimum flow level for the fan which brought it's overall vibration levels back into line with it's twin. The setting of the new flow rate also saw a reduction in the bearing frequencies which were identified. Finally, the changes in flow rate also resulted in a higher quality product for the client.