The muffler principle of muffler is to use the appropriate combination of cavity and tube to achieve two functions to muffle the sound:
One is to use the abrupt change of the cross section of the pipe (that is, the change in sound resistance) to reflect the sound wave propagating along the pipe back to the direction of the sound source, thereby reflecting the sound energy back to the original place;
The second is to use the reflection of several interfaces to make the original first forward-propagating sound wave return to the original point, and then fold back to forward-propagating again. This point merges with the second forward-propagating sound wave that has not yet been reflected, and The ones are equal in amplitude and differ by an odd multiple of 180 degrees in phase, thereby interfering with each other to cancel.
Fan type
It is mainly used to reduce the intake and exhaust noise of Roots series and axial flow fans. It can also be used to reduce the noise of exhaust pipes and other high-pressure fans. The amount of noise reduction is 15-30dB, and the pressure loss is less than 500Pa.
Structural principle of impedance acoustic flow type ventilation and exhaust pipes and fan silencer
According to the spectrum characteristic data obtained from the actual test of the noise sources of various types of industrial fan operation sites, determine in which frequency range the amount of noise reduction is needed as the main basis for designing the sound absorbing body and the fluid channel, while using a large absorption Narrow rectangular channels with acoustic material finishes to enhance absorption. In addition, when the noise source of the fan is at the maximum noise level, there is often more than one type of spectrum value, and the requirements for the amount of noise reduction are different for different frequency bands. For this reason, the series of ventilation duct muffler and blower fan muffler are impedance acoustic flow type, which adopts a resistive structure that plays a role in absorbing and attenuating high and medium frequency noise, and an anti-type that plays a role in reducing noise in mid and low frequency noise. Structure, at the same time, two high-frequency and low-frequency sound absorption and attenuation areas are used in the resistance channel to maximize the noise attenuation frequency band to achieve good noise reduction and noise reduction effects.
Exhaust
Boiler ignition exhaust muffler (TB) type In order to suppress the high-pressure steam exhaust noise, there are many types of mufflers in the world at present, and its principle is mostly multi-stage throttling and pressure reduction. Due to its complicated structure, heavy weight, it is difficult to disintegrate Overhaul, thus limiting its scope of application. The muffler of the new structure overcomes the above shortcomings.
This type of exhaust muffler is designed based on the most reasonable muffler principle. High-pressure steam enters the depressurization body after a flow control in the exhaust muffler after a large volume expansion, often due to various reasons such as the deviation of the exhaust steam, the noise is still higher than the standard value. To this end, a double-layer sound-damping cover was designed outside the buck, which was designed according to the spectral characteristics of the residual noise emitted by the buck to effectively absorb the residual noise. When the user installs as required, the total noise level should reach 36-42 dB.