Common Faults and Troubleshooting Methods for Air-Suspension Blowers

Air-Suspension Blower Although machinery is the epitome of high efficiency and energy conservation, it is by no means invincible. In actual operation, it places extremely stringent demands on the operating environment, as well as on proper handling and maintenance. In many cases, equipment failures are not caused by damage to core components, but rather by system protection mechanisms triggered by unsuitable environmental conditions or improper operation. To ensure continuous production, we must look beyond the surface symptoms of a failure to identify the root cause, conduct precise troubleshooting, and resolve the issue effectively.

I. Surge: the “Number One Killer” of Equipment Operation

Surge is one of the most hazardous malfunctions in centrifugal blowers. When the blower suddenly emits a low, pulsating “whoosh–whoosh” sound during operation, accompanied by severe pipeline vibration and large fluctuations in current and pressure, it indicates that the blower has entered the surge region. This typically occurs because the actual resistance of the piping network exceeds the pressure delivered by the blower, causing periodic backflow of air at the impeller.

In-depth investigation and handling:

• Check pipeline resistance : Conduct a comprehensive inspection of the exhaust piping to verify that the outlet valve is fully open, that there are no foreign objects obstructing the pipeline, and that downstream process parameters (such as the water level in the aeration tank) have not suddenly risen sharply, thereby causing excessive back pressure.
• Adjust the anti-surge valve : Check whether the anti-surge valve (BOV) is malfunctioning or if its set pressure is too high. You can try reducing the BOV’s opening pressure by 5–8 kPa to ensure that the valve automatically opens to relieve pressure under critical operating conditions.
• Optimize operating conditions : By appropriately increasing the rotational speed or enlarging the guide vane opening via the variable-frequency drive, the fan’s operating point can be rapidly shifted to the upper-right region, thereby moving it out of the surge zone. For applications with significant load fluctuations, it is recommended to install a recirculation loop to ensure that the fan consistently operates at more than 30% of its rated flow.

II. High-Temperature Alarm: A “Dual Challenge” of Intake Air and Heat Dissipation

High-temperature alarms are typically categorized into inlet-air temperature upper limits (e.g., code 170) and discharge/motor temperature upper limits (e.g., code 180). Air-suspension blowers are highly sensitive to the intake-air environment; high ambient temperatures in summer or inadequate ventilation in the equipment room are common triggers for such alarms.

In-depth investigation and handling:

• Verify the actual temperature : Sometimes a high-temperature alarm is a “false alarm.” You should check the temperature-sensor connectors on the intake and exhaust ducts for dirt or looseness, as sensor malfunctions can cause data drift. Try unplugging the connector, cleaning it, and then reinserting it to see whether the temperature reading returns to normal.
• Improve the data center environment : Ensure adequate ventilation in the fan room; during periods of excessively high ambient temperatures in summer, it is recommended to install industrial fans or air conditioning for forced cooling.
• Inspect for filter blockage : If the intake air filter is not cleaned for an extended period, accumulated dust will not only increase airflow resistance but also cause poor air intake, leading to localized overheating. The filter element should be cleaned or replaced regularly to ensure unobstructed air intake.

III. Abnormal Vibration and Noise: The “Alarm” for Dynamic Balancing and Installation

During normal operation, the vibration levels of air-suspension blowers are typically very low (≤2.5 mm/s). If significant increased overall equipment vibration is observed, or if high-frequency metallic rubbing noises or sharp whistling sounds occur, the equipment must be immediately shut down for inspection and troubleshooting.

In-depth investigation and handling:

• Impeller Dust Accumulation and Dynamic Balancing : In environments with high humidity and abundant aerosols, such as wastewater treatment facilities, the impeller is highly susceptible to dust and dirt adhesion, which can compromise its dynamic balance. It is recommended to perform dry-ice blasting or professional cleaning of the impeller every six months; direct water rinsing is strictly prohibited to avoid damaging the coating.
• Inspect pipeline stress : Inspect whether the inlet and outlet pipelines are lacking elastic flexible connections (expansion joints) or whether the pipeline supports are insufficiently rigid. Pipeline stresses caused by thermal expansion and contraction, when directly transmitted to the machine casing, can trigger severe vibration.
• Beware of “dry grinding” during start-up and shutdown. : If a 3- to 8-second metallic screeching sound is heard each time the equipment is started or stopped, it indicates that the gas film has not fully formed at low speeds, resulting in slight contact between the shaft and the bearing. Frequent starts and stops should be avoided as much as possible; after shutdown, maintain purging for 3 to 5 minutes, and regularly inspect the bearing clearance.

IV. Electrical and Inverter Faults: The “Barometer” of Power Supply Quality

Inverter faults (such as codes 141–147) or communication abnormalities are often not caused by the fan itself, but rather by substandard external power supply conditions.

In-depth investigation and handling:

• Monitoring power grid quality : Voltage sags exceeding 5% or excessive harmonic distortion will both trigger the wind turbine’s “loss of synchronism” or “loss of levitation” protection. For factories with unstable power grids, it is recommended to install an online UPS or an automatic voltage regulator cabinet.
• Inspect the cable and grounding : Long cables between the variable frequency drive and the motor can cause harmonic voltage drops, resulting in insufficient speed. Consider shortening the cable length (recommended to be less than 15 m) or installing a dV/dt filter at the output. In addition, ensure that signal cables are routed separately from power cables and use shielded cables to prevent electromagnetic interference.

V. Filter Differential Pressure Alarm: The Most Basic “Breathing Obstruction”

This is the most common routine alarm, indicating that the fan’s “first line of defense”—the intake air filter—has become clogged with dust, causing airflow resistance to exceed the safety threshold.

In-depth investigation and handling:

• Regular maintenance : Establish a rigorous maintenance and servicing plan: typically, blow out the main filter element with compressed air every two weeks, and replace the filter element every 3 to 6 months based on the differential pressure.
• Washing is strictly prohibited. : Most high-efficiency filter media must never be washed with water, as this will damage the fiber structure and degrade performance. If dust levels on site are extremely high, consider adding a preliminary pre-filter stage to the supply air ductwork.

By mastering the underlying logic behind these failures, we can not only swiftly restore production when equipment alarms are triggered, but also nip faults in the bud through routine preventive maintenance, thereby fully leveraging the air-suspension blower’s core advantages of high efficiency and long service life.