System analysis of common faults in multi-stage centrifugal blowers

Classification of core fault types and their causes

Fault category Typical fault manifestation Main cause

Mechanical vibration: The bearing seat/casing shakes violently, accompanied by abnormal noise. The impeller is covered with dust/corrosion, causing the rotor to be unbalanced; the coupling alignment is off; the anchor bolts are loose; the bearing is worn or the clearance is too large

Surge phenomenon: periodic reverse flow of airflow, sudden increase in noise, resonance of the entire machine, too low inlet flow or too fast closing of the outlet valve; sudden increase in system resistance; operation point entering the unstable zone (low flow zone)

Abnormal temperature: The temperature of the bearing or motor exceeds the limit, triggering an alarm and causing the machine to stop. This may be due to insufficient or contaminated lubricating oil; a failure in the cooling system; motor overload; or poor heat dissipation caused by high ambient temperature and dust accumulation

Performance degradation: insufficient air volume, low outlet pressure, clogged intake filter; worn or corroded impeller; seal leakage (labyrinth seal failure); blocked pipeline or valve

Seal failure: gas leakage, oil leakage, efficiency reduction, seal ring wear, shaft eccentricity, impurity intrusion; high temperature causes seal material aging; long-term vibration leads to seal loosening

Electrical and control issues: Motor fails to start, frequency converter reports errors, system malfunctions due to power supply phase loss, wiring is loose; frequency converter parameters are set incorrectly; sensor (temperature/vibration) malfunctions; PLC program is abnormal

Component damage: Impeller cracks, weld seam cracking, blade deformation, long-term erosion from dust/crystalline substances in the gas; resonance fatigue caused by dynamic balance failure; installation stress concentration; material corrosion

Data source: Comprehensive Industrial Operation Empirical and Equipment Diagnosis Manual, , .

In-depth analysis of high-frequency faults

1. Impeller dust accumulation and corrosion (highly prevalent in dusty environments)

Performance: The vibration frequency increases synchronously with the rotational speed, resulting in a 10–20% decrease in air volume and an increase in energy consumption.

Cause: Industrial dust (from the processing of building materials, ceramics, and quartz sand) in the Linyi area is easily inhaled and deposited on the surface of the impeller, disrupting the dynamic balance.

Consequences: Failure to clean up in a timely manner will result in blade deformation, weld cracking, and even resonance fracture.

Associated rich media:

2. Surge (the most dangerous aerodynamic failure)

Symptoms: The fan emits a "roar" or "breathing" sound, the pressure gauge fluctuates violently, the entire machine vibrates intensely, and there may be a sudden change in motor current.

Cause: The operating flow rate is lower than the minimum stable flow rate (usually 30% of the rated flow rate), and the outlet pressure is higher than the output pressure of the fan, causing airflow to flow backwards.

Consequences: Impeller impact damage, bearing seizure, seal tear, and in severe cases, complete machine scrapping.

Prevention: Install anti-surge valves to maintain a minimum flow bypass; utilize an intelligent control system to automatically adjust the rotational speed.

3. Overheating and wear of bearings

Symptom: Bearing temperature > 85℃, infrared temperature measurement alarm, increased vibration amplitude.

Cause:

Traditional models: deterioration of lubricating oil, blockage of oil circuit, insufficient cooling water;

Magnetic levitation model: Sensor drift and abnormal control algorithm lead to imbalance of levitation force.

Local risks: The dusty environment in Linyi accelerates the contamination of lubricating oil, thereby shortening the oil change interval.

4. The intake filter is clogged

Symptoms: Decreased air volume, increased motor current, accelerated temperature rise.

Cause: Failure to clean periodically (weekly inspection recommended), resulting in dust accumulation leading to a pressure difference >500Pa.

Consequence: Increased intake negative pressure, exacerbated impeller wear, and induced surge.

5. Seal leakage (labyrinth seal failure)

Symptoms: Oil leakage at the seams of the casing, gas leakage, and a 5–15% decrease in efficiency.

Causes: excessive shaft vibration, sealing clearance blocked by dust, and deformation due to high temperature.

Associated rich media:

Risk warning for special faults in Linyi, Shandong

Risk factors affecting equipment components and suggested countermeasures

In high dust environments, clean the impeller, filter, and bearing weekly, and clean the intake filter; choose impellers with anti-dust coating; install a secondary dust removal inlet

Regular dehumidification of electrical wiring terminals and control cabinets due to seasonal humidity; selection of control boxes with a protection level of IP54 or higher

Industrial vibration interference: tighten foundation bolts and pipe connections quarterly; install flexible connectors

Implement intelligent predictive maintenance for all mechanical components with lagging maintenance: Integrate PLC vibration/temperature data and set up automatic early warning

Local enterprises should give priority to domestic models equipped with intelligent monitoring systems (such as Zhanggu C series and Aizhen AS series) to achieve remote diagnosis and fault prediction.

Suggestions on fault diagnosis and handling priority

Fault level, Fault type, Handling priority, Operational suggestion

Emergency surge, bearing lock-up ⚠️ Immediately shut down the machine, cut off the power supply, open the anti-surge valve, and check the flow and pressure curves

The high-speed impeller is severely clogged with dust and experiencing seal leakage. ⚠️ Shut down the machine within 24 hours to remove the dust; replace the seals; and perform dynamic balance correction

The temperature of the bearing has risen and the filter is clogged. Clean the filter within 3-7 days; replace the lubricating oil; check the cooling system

Low control panel false alarms, indicator light abnormalities ⚠️ Plan to conduct maintenance, check sensor wiring, and calibrate parameters

Intelligent operation and maintenance trend: from "post-maintenance" to "predictive maintenance"

Technical path:

Deploy vibration sensors, temperature probes, and air pressure flowmeters, connect them to PLC and cloud platform, and collect real-time operational data.

AI diagnostic function:

Train a model using historical data to identify abnormal vibration spectra (such as increased peak values at 1× and 2× rotational frequencies) to predict impeller imbalance, or predict bearing failure based on the rate of temperature rise.

Local application value:

The Linyi Wastewater Treatment Plant has piloted this system, resulting in a 70% reduction in fault response time and an 85% decrease in unplanned downtime.

Recommended model: Domestic magnetic suspension blowers equipped with remote monitoring interfaces (Modbus TCP/MQTT) to achieve "unattended operation + intelligent early warning".

Shandong Ruidian Environmental Protection Technology Co., Ltd. is located in the high-end equipment manufacturing base of Luozhuang District, Linyi City. It is a modern enterprise that has always been dedicated to the research, design, production, and manufacturing of multi-stage centrifugal blowers, centrifugal vacuum pumps, roots blowers, pneumatic conveying systems, and specialized equipment for soil remediation integration