01Method of eliminating resonant noise

Only when the regulator resonates can the energy add up to produce a loud noise of more than 100 db.Some performance for vibration, noise is not big, some vibration is weak, but the noise is very big;Some vibration and noise are larger.This noise produces a single-tone sound, usually at a frequency of 3000 ~ 7000 hz. Obviously, the elimination of resonance, the noise will naturally disappear.

02Elimination of cavitation noise method

Cavitation is the main source of hydrodynamic noise.In cavitation, the bubble rupture produces high speed impact, which causes local strong turbulence and cavitation noise.This noise has a wide frequency range and produces a grating sound similar to that produced by a fluid containing sand and gravel.Eliminating and reducing cavitation is an effective way to eliminate and reduce noise.

03Use the thick-wall pipeline method

Thick wall tube is one of the acoustic treatment methods.Using thin wall can increase the noise by 5 db, using thick wall pipe can reduce the noise by 0 ~ 20 dB.The thicker the wall of the same pipe diameter, the larger the pipe diameter of the same wall thickness, the better the noise reduction effect.For example, when THE wall thickness of DN200 pipeline is 6.25, 6.75, 8, 10, 12.5, 15, 18, 20 and 21.5mm, the noise can be reduced to -3.5, -2(i.e. increase), 0, 3, 6, 8, 11, 13 and 14.5 dB, respectively.Of course, the thicker the wall the higher the cost of the rotor pump castor wine.

04Sound absorbing material method is adopted

This is also one of the more common and most effective sound processing methods.A sound-absorbing material can be used to enclose the noise source and the back pipe of the valve.It must be noted that the effectiveness of noise abatement ends where the absorbent material is encapsulated and where the thick-walled tube is used, because noise travels over long distances through fluid flow.This method is suitable for situations where the noise is not very high and the pipeline is not very long, as it is a more expensive method.

05Series silencer method

This method is applicable to the muffling of aerodynamic noise. It can effectively eliminate the noise inside the fluid and suppress the noise level transmitted to the solid boundary layer.This method is most effective and economical for high mass flow rate or high pressure drop ratio before and after the valve.The use of absorbent series silencers can greatly reduce noise.However, economic considerations generally limit the attenuation to about 25 decibels.

06Sound insulation method

07Use speakers, houses and buildings to isolate noise sources and reduce the external environment's noise to an acceptable level.

Series throttling method

In the control valve pressure ratio high (△P/P1≥0.8) occasions, the use of series throttling method, is the total pressure drop dispersed in the control valve and the valve after the fixed throttling components.Diffusers, perforated current limiting plates, are the most effective methods of noise reduction.For optimal diffuser efficiency, diffusers (physical shape, size) must be designed for each installation so that the valve produces the same noise level as the diffuser.

08Select low noise valve

Low noise valve according to the fluid through the valve valve core, control valve seat zigzag flow path (multi-channel, multi-groove) to avoid supersonic at any point in the flow path.There are a variety of forms and configurations of low noise valves (designed for special systems) available for use.When the noise is not very big, choose low noise sleeve valve, can reduce the noise 10 ~ 20 db, this is the most economical low noise valve.