A large 3.5m diameter brick oven fan was the cause of both occupational and environmental noise problems (the latter involving the local Environmental Health Officer). Occupational noise levels in the room next to the fan were dominated by low frequency tones giving an overall level of 90dB making the use of hearing protection mandatory. Tonal noise was also the cause of the environmental noise problem. Quotations for conventional treatments involved an enclosure, a requirement to move the fan to create space for a large silencer and a down-time of a few days. The overall cost would have been over £15000 and would have caused serious production difficulties as the fan is run 24 hours a day.
The overall noise level was reduced from 90dB down to 79dB.
This eliminated both noise problems quickly and effectively and at the same time reduced the overall cost from £15000 down to £1000. Moreover, no additional down-time was required to implement the modifications.
Industrial Noise and Vibration Centre Ltd.