Non volute centrifugal fan manufacturer shares fan noise control methods

The fan generates strong aerodynamic noise during high-speed rotation. To prevent sound transmission and allow airflow to pass through, a noise reduction device is installed in the fan airflow channel to reduce the noise generated by the fan itself and the aerodynamic noise in the pipeline,Non volute centrifugal fanThe commonly used noise reduction devices for manufacturers are:

(1) Resistive silencers commonly include sheet silencers, honeycomb silencers, tube silencers, and labyrinth silencers;

(2) Reactive silencers commonly include resonant silencers, expansion silencers, hybrid silencers, and barrier silencers;

(3) Impedance composite mufflers commonly use expansion chamber impedance composite mufflers, resonant cavity impedance composite mufflers, and impedance impedance co composite mufflers.

2、 Soundproofing

Sound insulation is a commonly used technical measure in noise control engineering, which uses various wall panels and components as shielding materials or maintenance structures to control noise within a certain range, blocking the propagation of noise in the air and preventing it from passing smoothly, thereby achieving the goal of reducing noise. Common methods include:

(1) Single layer dense and uniform sound insulation components require dense and thick sound insulation materials, such as brick walls, reinforced concrete, steel plates, wooden boards, etc. The sound insulation performance is related to the rigidity and damping surface density of the material;

(2) Double layer structure sound insulation, with a certain thickness of air sandwiched between two single-layer structures, or a composite structure of porous materials, can generally achieve 5-10 dB higher sound insulation than single-layer structures of the same mass;

(3) Soundproof enclosure and soundproof room. For small noise sources, directly covering them with soundproof structures can achieve significant noise reduction effects. This is called soundproof enclosure. When there are many scattered noise sources, it is possible to consider establishing a small space to isolate them from the noise source, which is called soundproof room;

(4) A soundproof screen is a sound insulation device made of a sound insulation structure placed between a noise source and a sound receiving point.

3、 Sound absorption

Decorating walls or ceilings with sound-absorbing materials, sound-absorbing structures, or hanging sound-absorbing panels in space will absorb the mixed sound of the sound-absorbing body. This method of controlling noise is called sound-absorbing noise reduction.

(1) Sound absorbing materials are very important in sound absorption and noise reduction methods. Commonly used materials include: ① fiber materials, including organic fibers, inorganic fibers, and fiber products; ② Granular materials, including blocks and boards; ③ Foam materials include more than 20 kinds of foam plastics and others.

(2) Resonant sound-absorbing structures are various sound-absorbing structures made using the principle of resonance, used for absorbing low-frequency sound waves. Commonly used structures include single resonant structures (including thin film and thin plate structures) and perforated panel sound-absorbing structures.

(3) The micro perforated panel sound absorption structure is a composite structure composed of metal micro perforated panels with a thickness and aperture of less than 1mm and a perforation rate of 1% to 3%, and cavities.