风机适用于各个生产行业，不论在哪个行业上用途都很广泛性，但是在运作中会产生一些噪音，噪音污染会对工作人员健康造成损害，所以离心风机的降噪是不可缺少的，为大家总结了几个有效的降噪方案可以给大家参考：
Fan is suitable for various industries, no matter which industry is widely used, but it will produce some noise in operation, noise pollution will cause damage to the health of staff, so the noise reduction of centrifugal fan is indispensable.
1、风机降噪-合理的蜗舌间隙和蜗舌半径fan noise reduction - reasonable tongue gap and tongue radius.
当气流与叶片做相对运动时，叶片后缘的气流尾迹中速度及压力均小于主流区，使叶栅后的气流速度与压力分布皆不均匀，这种不均匀的气流在旋转，由于在动叶的气流出口有蜗舌存在，则这种非稳定流动与蜗舌相互作用将产生噪声， 距离噪声愈近噪声愈烈，通常适当取较大的风舌前端半径可以降低离心风机的旋转噪声与涡流噪声。
When the air flow is relative to the blade, the velocity and pressure in the airflow wake of the rear edge of the blade are less than the mainstream, and the airflow velocity and pressure distribution behind the cascade are not uniform. This uneven airflow is rotating, and the interaction between the unsteady flow and the tongue will produce the existence of the worm tongue at the outlet of the moving blade. When the noise is getting closer and closer to the noise, the rotating noise and vortex noise of the centrifugal fan can be reduced by properly selecting the front radius of the larger wind tongue.
2、风机降噪-蜗舌倾斜The noise reduction of the fan - the slanting of the tongue
风机叶轮叶栅气流的周期性脉动速度所产生的周期性脉动气动力也使蜗舌相互作用产生旋转噪声，此噪声大小与脉动气动力的剧烈程度及涡舌的迎风面积有关，把蜗舌做成倾斜式，则同相位的脉动气动力的作用面积小了，辐射的噪声也就减小了。
The periodic pulse kinetic aerodynamic force produced by the periodic pulsation velocity of the fan impeller blade cascade also causes the cochlea interaction to produce rotating noise, which is related to the intensity of the pulsating aerodynamic force and the windward area of the vortex tongue, and makes the worm tongue inclined, and the area of the pulse kinetic aerodynamic force at the same phase is smaller. The noise is also reduced.
3、风机降噪—采用消声隔声箱fan noise reduction - the use of noise reduction and sound insulation box
控制风机噪声的常用方法是在风机的进、出口处安装阻性消声器。对于有更高降噪要求的场合，可以采用消声隔声箱，并在机组与地基之间安置减震器。
The common way to control fan noise is to install a resistive silencer at the inlet and outlet of the fan. For occasions with higher noise reduction requirements, noise elimination and sound isolation boxes can be used, and shock absorbers should be installed between the units and the foundation.
对于风机采用强前向叶片，且多叶片叶轮有利于增大叶栅的气动力载荷，在得到同样风量风压情况下，叶轮叶片外圆上圆周速度可使风机噪声明显降低。
For the wind turbine with the strong forward blade, and the multi blade impeller is beneficial to increase the aerodynamic load of the cascade. Under the same wind pressure condition, the circular velocity of the outer circle of the impeller blade can reduce the fan noise obviously.
4、风机降噪—叶轮入(出)口处加紊流化装置Fan noise reduction - add turbulence device to impeller.
在风机叶轮叶片的入口或出口处加紊流化装置(金属网)可以使叶片背面的层流附面层立即转换成紊流附面层， 推迟叶片背面附面层的分离，甚不分离， 叶片后缘装上网，网后的气流速度与压力梯度能迅速变均匀，若网在涡区中则可将涡区大大缩小,可进一步减噪.
A turbulent flow device (metal mesh) is added at the entrance or exit of the blade of the fan. The laminar laminar layer on the back of the blade can be converted into a turbulent boundary layer immediately. The separation of the surface layer on the back of the blade is postponed or even separated. The back edge of the blade is not separated. The flow velocity of the blade and the pressure gradient can be quickly uniform, if the net is in the vortex area. In addition, the vortex region can be greatly reduced and the noise reduction can be further reduced.
5、风机降噪—在蜗舌处设置声学共振器Fan noise reduction - acoustic resonators installed at the tongue of the worm.
蜗舌处设置声学共振器，当声波传到共振器时，小孔孔径和空腔中的气体存声波作用下来回运动，这运动的气体具有一定的质量，它抗拒由于声波作用而引起的运动，同时声波进入小孔孔径时，由于颈壁的摩擦和阻尼，使相当一部分声能因热耗而损失掉。另外充满气体的空腔具有阻碍来自小孔的压力变化的特性，由于这些因素的共同作用，当气体通过共振器时，噪声得到了降低。
The acoustic resonator is set up at the tongue of the worm. When the acoustic wave is transmitted to the resonator, the aperture of the hole and the gas in the cavity are played down and back to motion. The gas of the motion has a certain mass. It resists the motion caused by the sound wave action. At the same time, when the sound wave enters the aperture of the hole, it is equivalent to the friction and damping of the neck wall. Some of the sound energy is lost because of heat consumption. In addition, the cavity filled with gas has the characteristics that obstruct the pressure change from the hole. Because of the common action of these factors, the noise is reduced when the gas passes through the resonator.
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