During long-term operation, fans may encounter issues such as increased vibration and noise, insufficient airflow, bearing overheating, and duct blockages. This guide systematically covers common failure types, diagnostic methods, and rapid maintenance processes, helping engineers and maintenance personnel quickly identify and resolve problems to ensure safe and stable ventilation system operation.
1. Common Fault Types
Abnormal vibration: Causes include imbalance, loose foundation bolts, and worn couplings.
Increased noise: Causes include airflow separation turbulence, blade damage, and insufficient bearing lubrication.
Insufficient airflow or pressure: Causes include duct leaks, clogged filters, or partially closed valves.
Bearing overheating: Causes include lack of lubrication, excessive axial/radial clearance, or aged seals.
Electrical faults: Causes include loose wiring, shorted windings, or poor grounding.
2. Diagnostic Process
Visual and auditory inspection: Check for cracks, loose bolts, and listen for unusual noises.
Vibration analysis: Use sensors or handheld tools to assess vibration frequency and amplitude.
Temperature monitoring: Use thermal imaging or infrared thermometers to detect bearing, housing, and winding temperatures.
Airflow/pressure testing: Compare on-site measurements with design values to assess ductwork condition.
Electrical testing: Use multimeters or insulation testers to check wiring and motor windings.
3. Rapid Maintenance Process (Goal: Restore operation within 2 hours)
Safe shutdown and isolation: Cut off power as per procedures, tag out, lock valves, and secure for maintenance.
Preliminary cleaning and inspection: Remove dust and debris from impellers, guide vanes, and cooling fins.
Fault component handling:
Vibration/imbalance: Remove and rebalance impeller.
Bearing issues: Add or replace grease, change bearings if needed.
Blockage/leakage: Clean filters, repair gaskets.
Tightening and adjustments: Retighten bolts and coupling nuts to recommended torque.
Trial run and monitoring: Restore power, start at low speed, monitor vibration, noise, temperature, and airflow.
Documentation and reporting: Record fault causes, remedies, and running parameters; update maintenance records.
4. Preventive Maintenance Recommendations
Online monitoring: 24/7 tracking and alerts for vibration, temperature, and airflow.
Regular maintenance: Monthly bearing lubrication, quarterly balancing and thermal inspections.
Staff training: Develop and rehearse emergency and maintenance procedures.
Spare parts management: Maintain adequate stock of common wear parts (bearings, seals, filters).