Our GF series of fan silencers and noise dampeners are designed to mitigate aerodynamic noise caused by fans on the environment. They are used for silencing the intake and exhaust air ducts of various centrifugal and ventilation fans.
Fans are a type of general machinery equipment, widely used across various industries such as power, mining, machinery, metallurgy, and chemical engineering. Fans are indispensable for the production in these sectors. The noise generated during their operation often becomes a source of health issues for workers and interference. Particularly, fans located near residential areas, with their intake and exhaust air streams emitting aerodynamic noise, are a major factor in environmental pollution, causing public nuisance. They have become one of the main targets for pollution control efforts by China's industrial sector in recent years.
Industrial fans, designed for continuous operation. The International Organization for Standardization (ISO) sets noise standards for such equipment at ≤90 decibels. Our country's new standards are identical, serving as the basis for industrial enterprises to meet continuous noise requirements. However, without noise reduction measures, the noise emitted from the intake and exhaust of the fan can reach 110-120 decibels, significantly exceeding the standard requirements.
This muffler series is of the impedance type. Our factory determines the necessary sound absorption levels for the design of the absorptive panel structure and fluid channels based on frequency characteristics obtained from actual noise source tests at power plant fan operation sites. Additionally, we use narrow rectangular channels with large absorbent material coatings to enhance absorption effectiveness. The product employs resistive structures for high and medium-frequency noise reduction and resistive structures for medium and low-frequency noise reduction. It also utilizes both high-frequency and low-frequency absorption zones within the resistive channels to maximize the broadening of the sound absorption frequency range, achieving excellent muffling performance.
Once installed according to specifications, this product's maximum noise level will not exceed 75-80 decibels. The muffler described in this manual is suitable for all types of centrifugal and axial flow ventilators. In addition, our factory also designs and produces mufflers for various applications, including gas turbines, Roots blowers, air compressors, and diesel engine exhausts. Welcome to inquire and purchase.
Dust extractors, exhaust fan silencers, and air blower silencers are all designed with noise reduction principles that effectively handle mid and high-frequency broadband characteristics, such as resistive sound absorption, and offer good results for low and mid-frequency as well as pulsating characteristics through resistive noise attenuation. Additionally, micro-perforated silencers and impedance composite silencers are utilized.
A resistive silencer is an absorbing type of silencer, which is generally categorized into straight-tube, plate, corrugated plate, honeycomb, acoustic flow, labyrinth, and elbow designs based on the structure of the airflow channel. It operates by converting sound energy into heat energy and dissipating it through friction and viscosity resistance as sound waves propagate through porous sound-absorbing materials, thereby achieving the purpose of noise reduction. It is the most widely used category of silencers among all types.
The resistance muffler differs from the resistive muffler in its noise reduction principle. It does not directly absorb sound energy but utilizes abrupt interfaces on the pipeline or auxiliary resonant cavities to cause reflection and interference phenomena in certain frequency sound waves propagating along the pipeline, thereby achieving the purpose of noise reduction. It is categorized into expansion chamber mufflers and resonant mufflers.
In practical noise control engineering, noise is predominantly宽带, so it is common to combine resistive sound absorption and resistive sound attenuation structures to control intense宽带noise.
1. Structure and Principle of Impedance Sound Flow Type Ventilation, Exhaust Ducts, and Fan Mufflers (Fan Silencers)
Based on the frequency spectrum characteristics obtained from actual testing of the noise sources at various industrial fan operation sites, we determine the required amount of noise reduction at which frequency ranges for designing the main acoustic absorption bodies and fluid channels. Additionally, we employ narrow rectangular channels with a large acoustic material covering to enhance absorption effects. Moreover, at the highest noise level, the noise sources of the fan often have more than one frequency value, and the noise reduction requirements for different frequency bands vary accordingly.
The GF series silencers for ventilation ducts and exhaust fans are both impedance type, utilizing resistive structures for absorbing and attenuating high and mid-frequency noises and reactive structures for noise reduction and attenuation of mid and low frequencies. Additionally, they incorporate both high and low-frequency absorption and attenuation zones within the resistive channels, broadening the silencing frequency range to achieve optimal noise reduction effects.
The GF series exhaust silencers for ventilation duct fans and blowers, as well as for centrifugal, axial, and Roots blowers and air compressors, are suitable for various types.
2. Impedance flow-type muffler (Airflow muffler) applications and product features:
Fans are a general type of mechanical equipment with a wide range of applications, essential in various industries such as power, mining, machinery, metallurgy, and chemical engineering. The noise generated during the operation of fans often becomes a source of harm to workers' health and environmental disruption. Particularly, fans located near residential areas, with their intake and exhaust air streams radiating aerodynamic noise, are a major factor in environmental pollution, causing public nuisances. They have been one of the main targets for noise pollution control in China's industrial sector in recent years.
Industrial fans, designed for continuous operation. The International Organization for Standardization (ISO) specifies noise standards for such equipment at ≤90 decibels. Our national standards are identical, serving as the basis for continuous noise compliance in industrial enterprises. However, without noise reduction measures, the noise emitted from the intake and exhaust of the fan can reach 110-120 decibels, significantly exceeding the compliance requirements.
This series of silencers (fan silencers) is of the impedance acoustic flow type. Our factory determines the required noise reduction levels across various frequency spectrums based on actual test data obtained from noise sources at power plant fan operation sites, which serves as the primary basis for designing the acoustic absorption panel structure and fluid channels. Additionally, we employ narrow rectangular channels with large acoustic material surfaces to enhance absorption. We understand that the noise sources of fans often have multiple frequency values at maximum noise levels, and the noise reduction requirements vary for different frequency bands. Therefore, this product utilizes resistive structures for high and medium-frequency noise reduction and resistive structures for medium and low-frequency noise reduction. Furthermore, we incorporate both high-frequency and low-frequency noise reduction zones within the resistive channels to maximize the broadening of the noise reduction frequency band, achieving an excellent noise reduction effect.
