What are the effective noise reduction measures for the noise problem generated when the negative pressure fan is running?

1. Noise reduction at the source
Adjust the installation status: ensure that the negative pressure fan is installed smoothly, and the bottom plate is padded to avoid vibration and noise caused by improper installation.
Adjust the installation status of the fan so that it is in a suspended state to avoid the spring of the base bolt being crushed, thereby reducing vibration and noise.
Optimize the fan structure: Check and adjust the fan blades to ensure that the fan blades do not collide with the fan housing (cover) to avoid the noise generated. Adjust the distance between the top of the blade and the cover according to the production technical requirements, generally not more than 1.5% of the blade length, to reduce the noise when the fan blade rotates.
Replace or maintain parts: The motor bearing of the negative pressure fan is bad, the screws of the axial flow fan base are loose, and the fan blades are not fixed on the shaft. Problems may cause noise. For these problems, you can replace the motor bearings, tighten the screws on the base and shaft, and other measures to reduce noise.

2. Transmission path noise reduction
Install vibration dampers: Install vibration dampers, such as damping spring dampers, on the base or installation location of the negative pressure fan to reduce the impact of fan vibration on the surrounding environment and structure, thereby reducing noise.
Use silencer equipment: Install silencer equipment, such as silencer shutters or silencers with built-in silencer inserts, at the exhaust or outlet of the fan to reduce the impact of aerodynamic noise.
Install soundproof covers: Use sound-absorbing bodies composed of metal or non-metallic soundproof panels, rock wool and perforated plates, etc. to install soundproof covers for negative pressure fans to reduce the spread of noise. At the same time, reasonably set up the ventilation and heat dissipation system, and install soundproof doors and windows to facilitate workers' inspections and equipment maintenance.

3. Other measures
Power supply voltage control: Control the power supply voltage within the rated voltage range to avoid abnormal noise and vibration caused by too low power supply voltage when the negative pressure fan is started or running. Usually, a voltage stabilizer or power supply voltage regulator can be used to stabilize the voltage.
Regular inspection and maintenance: Regularly inspect and maintain the negative pressure fan, including cleaning the fan blades, checking whether the fasteners are loose, lubricating the bearings, etc., to ensure the normal operation of the fan and reduce noise.
Professional consultation and transformation: For complex noise problems, you can consult professionals for professional noise assessment, control plan design and transformation implementation.