Our GF series of fan muffler and noise suppressor products are designed for the attenuation of aerodynamic noise caused by fans on the environment. They are used for noise reduction in the intake and exhaust ducts of various centrifugal and ventilation fans.
Fans are a type of general machinery equipment with a wide range of applications, indispensable in the production of various industries such as electricity, mining, machinery, metallurgy, and chemical engineering. The noise generated by fans during operation often becomes a source of health issues for workers and interference. Particularly, fans located near residential areas, with their intake and exhaust air ducts emitting aerodynamic noise, are a major factor in environmental pollution, causing public nuisances. 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 fans can reach 110-120 decibels, significantly exceeding the standard requirements.
This muffler series is of impedance acoustic flow type. Based on the frequency characteristics data obtained from actual tests of various fans' noise sources in power plants, our factory determines the required amount of noise reduction in specific frequency ranges for the design of the absorptive panel structure and fluid channels. It also employs narrow rectangular channels with a large surface area of absorbent material to enhance absorption. The product features a resistive structure for high and mid-frequency noise reduction and an antiresonant structure for mid and low-frequency noise reduction. Additionally, it incorporates both high-frequency and low-frequency noise reduction zones within the resistive channels to maximize the noise reduction frequency range, achieving an excellent muffling effect.
Once installed according to specifications, this product's maximum noise level will not exceed 75 to 80 decibels. The silencer introduced in this manual is suitable for all types of centrifugal and axial flow fans. In addition, our factory also designs and produces silencers for various applications such as gas turbines, Roots blowers, air compressors, and diesel engine exhausts. Welcome to inquire and purchase.
Duct mufflers, fan silencers, exhaust pipe silencers, and exhaust fan silencers all utilize a resistive noise reduction principle with good performance on medium and high-frequency broadband characteristics, as well as a reactive noise reduction principle that works well on low and medium frequencies and pulsation characteristics, along with micro-perforated silencers and impedance composite silencers.
A resistive silencer is an absorbing type of silencer, which is generally categorized into straight tube, sheet, 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 noise reduction. It is the most widely used type of silencer among all.
The resistance muffler operates on a different principle than the resistive muffler for noise reduction. It does not directly absorb sound energy but instead utilizes abrupt interfaces on the pipeline or auxiliary resonant cavities to cause certain frequency sound waves propagating along the pipeline to reflect and interfere at the interfaces, 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-absorbing and resistive sound-damping structures to control intense宽带 noise.
1. Structural Principle of Impedance Acoustic Flow Ventilation, Exhaust Ducts, and Fan Mufflers (Fan Silencers):
Based on the spectral characteristics obtained from actual noise source testing of various industrial fans, determine the required noise reduction levels in specific frequency ranges for designing acoustic absorbers and fluid channels. Additionally, a narrow rectangular channel with a large acoustic material covering is employed to enhance absorption. Furthermore, at the maximum noise level, the frequency spectrum of the fan's noise source often includes more than one value, and the noise reduction requirements vary for different frequency bands.
The GF series ventilation duct silencers and exhaust fan silencers are both impedance type, utilizing resistive structures for high and medium-frequency noise absorption and antireflexive structures for medium and low-frequency noise reduction. Additionally, both high and low-frequency noise absorption zones are incorporated into the resistive channels to maximize the bandwidth of the noise reduction, achieving an excellent sound absorption and noise reduction effect.
The GF series ventilation duct silencers and exhaust fans are suitable for various centrifugal, axial, Roots blowers, and air compressors.
2. Impedance-type acoustic flow muffler (Airflow muffler) application and product features:
Fans are a type of general machinery equipment with a wide range of applications, essential in various industries such as power, mining, machinery, metallurgy, and chemicals. The noise generated during their operation often becomes a source of harm to workers' health and environmental disruption. Particularly, fans located near residential areas, with their intake and exhaust airflow generating aerodynamic noise, are a major factor in environmental pollution, causing public nuisance. 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) sets noise standards for such equipment at ≤90 decibels. Our national standards are in line with this, 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 fans can reach 110-120 decibels, significantly exceeding the compliance standards.
This series of silencers (fan silencers) is of impedance acoustic flow type. Based on the actual test data obtained from the noise sources of various fans in power plants, our factory determines the required amount of noise reduction at different frequency ranges, which serves as the primary basis for designing the acoustic absorption panel structure and fluid passages. A narrow rectangular channel with a large acoustic material surface has been adopted to enhance the absorption effect. We know that at the highest noise level, the frequency spectrum values of the noise source from fans can be more than one, and the noise reduction requirements for different frequency bands are also different. Therefore, this product uses resistive structures for high and mid-frequency noise reduction and resistive structures for mid and low-frequency noise reduction. At the same time, both high and low-frequency noise reduction zones are adopted in the resistive channels to maximize the broadening of the noise reduction frequency band, achieving excellent noise reduction performance.
