How to judge the increase in EFU noise? Pneumatic, mechanical and structural noise investigation methods
Direct answer: If the noise increases after the EFU has been running for a period of time, the time of occurrence, operating gear, filter status and sound characteristics should be recorded first. Damage to the fan cannot be determined by hearing alone, nor should sound-absorbing materials be directly installed to cover the problem, because the noise may indicate that the inlet is blocked, the impeller is unbalanced, or the structure is loose.
Do a comparison test first
Compare different speed gears, adjacent equipment of the same model and initial data under safe conditions. Record the sound pressure level, measurement location, environmental background sound, air volume, pressure difference and vibration to ensure that the results are reproducible.
Common sources of aerodynamic noise
Insufficient distance between the air inlets, blocked grilles, biased inlet flow, increased filter resistance, or local air ducts that are too narrow may produce broadband airflow sounds. At this time, the noise usually changes with the rotation speed and resistance.
Common sources of mechanical noise
Uneven dust accumulation on the impeller, loose fastening, worn bearings, friction of rotating parts or abnormality of the motor will produce periodic or sharp sounds. When abnormal vibration, temperature rise or friction is found, the machine should be stopped for inspection.
Structure-borne Noise and Resonance
The vibration of the EFU body can be amplified by the equipment frame. Check fixation points, support stiffness, panel contact, cable impact and resonance at specific rotational speeds. Vibration reduction treatment should be based on the confirmed structural problems.
Review performance simultaneously after processing
Noise reduction cannot be achieved at the expense of necessary air volume. After adjusting the air inlet, fastening, fan or speed, the air volume, uniformity, power and temperature rise should be re-measured.
FAQ
If the noise becomes louder, must the filter be clogged?
Not necessarily, the filter is only one possible cause, the inlet, fan and structure should also be checked.
Can reducing the speed solve the noise?
It is possible to reduce the sound, but if the air volume in key areas is insufficient, it cannot be considered a qualified solution.
How to distinguish device background sound?
Compare the background sound and EFU operation under unified measurement points and equipment status, and refer to adjacent equipment.
How Aili Industry cooperates in analyzing EFU noise issues
Increased EFU noise can be investigated from three directions: aerodynamic noise, mechanical noise and structural vibration transmission. Aerodynamic noise is usually related to air inlet obstruction, changes in air ducts, excessive speed or working point deviation; mechanical noise may be related to the status of fans, motors, impellers and fasteners; structural noise may be transmitted and amplified through equipment frames or sheet metal parts.
When troubleshooting, you should first confirm the time and operating status of the noise, and then compare the changes at different speeds. Then check the filter resistance, air inlet, fan fixation, motor operation and box structure to avoid directly increasing or decreasing the speed without determining the cause.
Aili Industrial can help determine the source of noise based on EFU configuration, installation method and on-site recording or test data. For new projects, the relationship between air volume, static pressure, rotation speed and noise can be checked during the prototype stage, and installation and operating parameters can be optimized based on the equipment structure.
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Conclusion: When EFU noise increases, it is necessary to first determine whether the sound changes with rotation speed, air volume or structural contact. Obstructed inlet and high resistance are mostly manifested as aerodynamic noise, impeller or bearing abnormalities are mechanical problems, and looseness and resonance are related to the installation structure.
