This article analyzes three typical fan accident cases to reveal the causes of vibration and noise hazards, and proposes prevention strategies from dynamic balancing, foundation design, and vibration/noise isolation to help engineers effectively avoid operational risks and enhance system safety and comfort.
1. Case Analysis
Foundation Loosening and Resonance:
At a coal mine, loose anchor bolts on the main fan’s foundation led to resonance in the mid-to-high speed range, causing severe shell vibration and even cracks.Imbalance of Impeller:
In a cement plant, a local ventilation fan with excessive impeller manufacturing tolerances and lack of on-site dynamic balancing caused periodic impact vibrations during operation, resulting in severe bearing damage.Pipe Coupling Noise Amplification:
In a chemical plant exhaust system, improper fan outlet duct layout created standing sound waves, amplifying noise at pipe elbows and causing site-wide noise to exceed standards.
2. Vibration Hazards and Preventive Measures
Imbalance and Misalignment:
Regular dynamic balancing of impellers and shaft alignment checks.
Foundation and Support Design:
Use concrete foundations and prestressed anchor bolts for solid support.
Install elastic vibration-damping pads or spring isolators to reduce vibration transmission.
Bearings and Couplings:
Select high-quality vibration-damping couplings to minimize axial/radial loads.
Perform regular lubrication and monitor bearing temperature and vibration trends.
3. Noise Hazards and Control Strategies
Aerodynamic Noise:
Optimize blade profiles via CFD to reduce separation turbulence.
Mechanical Noise:
Use low-noise motors and ensure correct tolerances in transmission parts.
Structural Resonance:
Add sound-insulating felt or absorbent material at the junctions of the casing and ductwork.
Silencing Devices:
Install silencers at outlets and mid-pipe sections to reduce noise leakage.
4. Design and Operation & Maintenance Recommendations
Comprehensive Balancing and Isolation:
Conduct dynamic balancing at installation, use online vibration monitoring, and apply elastic foundations during operation.
Noise Modeling and Testing:
Perform noise simulation in the design phase and post-installation noise level tests; add necessary silencers.
Online Monitoring and Early Warning:
Deploy vibration sensors and sound level meters for remote diagnostics and early alerts.
By following these cases and countermeasures, you can address fan selection, foundation design, vibration/noise isolation, and routine O&M with targeted solutions, ensuring safe, reliable, and low-noise operation of your ventilation system.