Practical Applications of Silencers for Noise Reduction in Small Explosion-Proof Centrifugal Fans

Practical Applications of Silencers for Noise Reduction in Small Explosion-Proof Centrifugal Fans

In small rooms equipped with small explosion-proof centrifugal fans, sound-absorbing materials can be used to line the interior walls to prevent multiple noise reflections. The effectiveness of noise reduction becomes more pronounced depending on the room’s soundproofing measures. Common sound-absorbing materials include glass wool, foam plastic, slag wool, felt, wood fiber boards, and sugarcane boards—all of which are porous and have low density. The performance of sound-absorbing materials primarily depends on their sound absorption coefficient. Generally, using small explosion-proof centrifugal fans to reduce indoor noise results in a reduction of no more than 6 dB to 10 dB. This method only absorbs reflected sound from indoor sound sources (not all reflected sound) and does not directly affect the sound emitted from the source. Sound absorption treatment is not particularly effective in spacious rooms. Therefore, this method must be carefully considered when addressing noise in dust-extraction rooms. In noise control projects for fans in electroplating plant exhaust systems, taking into account both cost-effectiveness and sound absorption performance, small explosion-proof centrifugal fans are not equipped with large-area sound-absorbing materials indoors; instead, a 1-centimeter-thick layer of sound-absorbing material is installed in small rooms with densely packed panels. The base of the small explosion-proof centrifugal fan is embedded in a concrete platform. To prevent slight vibrations from the fan base from being transmitted to the ground, rubber shock-absorbing pads are installed beneath the platform. Rubber flexible connectors are installed at the inlet and outlet of the small explosion-proof centrifugal fan, and a fiberglass-reinforced plastic (FRP) Erbo silencer is also installed at the fan’s outlet. The enclosure features a double-wall construction with the inner wall embossed with numerous 1-mm holes. The inner wall has a smooth curved surface, and the distance between the inner and outer walls is 100 mm. To absorb noise caused by wind speed, the space between the two walls is filled with thin glass wool, allowing both walls to function as sound absorbers. The noise level measured below the window on the outer wall of the small explosion-proof centrifugal fan was 43 dB. Additionally, measures such as reducing the fan’s vibration and applying thermal insulation and soundproofing to the fan and air ducts have demonstrated a certain degree of effectiveness in noise reduction. In summary, when selecting, installing, and operating small explosion-proof centrifugal fans, incorporating measures for sound insulation, sound absorption, and noise reduction can minimize fan noise and meet environmental protection requirements. At the same time, factors such as the impact of other noise conditions in the surrounding environment, investment costs, and the operator’s maintenance and management capabilities must also be taken into account.