Fan silencer

Abstract

The invention relates to a fan silencer which can be used in inlets, outlets, and ventilation exhaust channels of centrifugal fans, axial flow fans, and fan turbine engines, and can be used in outlets of cooling tower fans; and the fan silencer is excellent in sound attenuation and noise reduction, is large in acoustical absorption coefficient, is wide in noise elimination frequency band, is shock resistant, is small in wind resistance, is high temperature resistant, high pressure resistance, high humidity resistant, and is anti-freeze. The fan silencer is characterized in that a skeleton is properly welded to an inner wall of an outer cylinder; an outer cylindrical sound absorber is assembled and formed by welding and riveting fixation; the center of the outer cylinder is provided with a central cylindrical sound absorber attached to the skeleton; more than two radical radiation sheet type sound absorbers and more than two radical radiation sheet type sound eliminators are arranged between the central cylindrical sound absorber and the outer cylindrical sound absorber, the sheet type sound absorbers and the sheet type sound eliminators are evenly and alternatively arranged, the skeleton at two ends of the sheet type sound absorbers and the sheet type sound eliminators are tightly fixed on a central cylindrical sound absorber skeleton and an outer cylindrical sound absorber skeleton through fasteners, and are fixed and assembled with the central cylindrical sound absorber skeleton and the outer cylindrical sound absorber skeleton through welding and rivets to form a set of product.

Description

Technical field [0001] The invention relates to a fan noise reduction device in acoustics, especially a device for various types of centrifugal fans, blowers, axial flow fans, aircraft turbojet engines, aircraft turbofan engines, large blower inlets and outlets, and ventilation and exhaust ducts. Among them, as well as a noise reduction device for the fan outlet of the cooling tower. With the continuous strengthening of environmental awareness, noise pollution is increasingly concerned by people. Fans are one of the important sources of noise pollution. This noise reduction device is suitable for metallurgy, mines, etc. , petroleum, thermal power generation, nuclear power, chemical industry, textile, machinery, construction, shipbuilding and other industrial sectors and civil sectors, all kinds of fans are widely used, by adding mufflers at the inlet and outlet of the fan, basically can or can Reduce noise to the requirements of environmental noise standards. [0002] Centrif...

AI Technical Summary

Problems solved by technology

[0011] For example, Chinese Patent Publication No.: 90201253.3 "Double-layer Resistive Muffler" discloses a noise that is mainly used to reduce the fan noise in the ventilation air-conditioning purification system. When the wind speed is 4-8m / s, the pressure loss of each muffler is 4-8 14Pa, each length of 950mm muffler has a noise reduction of 19~23dB(A). Although it has a significant noise reduction effect on medium and high frequency noise, it also has some shortcomings: the scope of application of this type of muffler is narrow, and the noise reduction effect is mainly Preference for high-frequency sound, the noise reduction effect is poor in high-pressure and high-speed airflow, etc.

[0012] The noise of the cooling tower is mainly fan noise and water spray noise, and the fan noise at the air outlet of the cooling tower fan is 5-20dB(A) larger than the water spray noise at the air inlet; the current noise control methods include noise reduction, sound absorption, sound insulation, A variety of technical measures such as vibration isolation and damping vibration reduction have achieved certain results through these measures; another example is the Chinese Patent Publication No.: 97227679.3 "Membrane Resonance Cooling Tower Muffler" discloses a method of sticking on both sides of the sound-absorbing body dragon frame Although the cooling tower muffler of the rigid plastic film sound absorbing body has a significant noise reduction effect on low-frequency noise, it also has some shortcomings: the cooling tower fan noise reduction is small, and the noise reduction is 4-6dB(A) , the sound absorption coefficient of the sound absorbing body is small, it is easy to age in the high-temperature and high-humidity airflow, and it is not anti-open flame, etc.

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