noise and vibration

Noise and vibration are common complaints in mining ventilation systems, especially for auxiliary ducted fans operating close to workers. These issues are not only comfort problems—they can also be early signs of unstable operation, mechanical stress, or poor system matching. In many cases, excessive noise and vibration occur when a fan is operating far from its best efficiency and stable region on the curve.

Typical causes include:

• Off-duty operation: oversizing or unexpected resistance shifts push the operating point into inefficient or unstable zones.
• Duct effects: sharp bends, restrictions, and poor transitions increase turbulence and tonal noise.
• Installation quality: misalignment, weak mounting, and poor foundation amplify vibration.
• System pulsation: leakage, unstable regulators, or recirculation patterns can create fluctuating pressures.

The most effective control method is still correct selection: define the required end-of-duct airflow and match the fan to the realistic Q@Ps duty point with usable margin. Where operating conditions vary, VFD control helps keep the fan within a stable region and avoid “forcing” performance by running at inefficient speeds. On the system side, improving duct routing, avoiding sharp transitions, and maintaining duct integrity reduce turbulence and pressure fluctuations that drive noise.

For installations with strict noise expectations, practical measures include properly selected silencers, flexible connectors, vibration isolators, and careful support design. Measurement and inspection matter: a sudden increase in vibration often indicates duct damage, new restrictions, or mechanical issues that should be addressed before reliability is affected.

Bottom line: noise and vibration are usually symptoms of a system problem—either operating point mismatch or installation and ducting issues. Fixing the cause improves both worker conditions and ventilation reliability.