Introduction to the types of mufflers
At present, the muffler is mainly divided into the following types:
Resistive muffler, also known as absorption muffler, uses sound-absorbing materials to absorb noise. The sound-absorbing material has a loose and porous structure. Sound waves enter the pores and cause small vibrations. Due to friction and viscous resistance, a considerable part of the sound energy is converted into heat and is absorbed.
The resistive muffler has a good sound absorption effect on high frequency and intermediate frequency noise, but has poor silencing performance on low frequency noise. It is mainly used to eliminate high frequency and high intermediate frequency noise.
Tubular muffler is used for air ducts with a diameter of not more than 400mm, and only a layer of sound-absorbing material is attached to the inner circumference of the pipe wall, which is simple to manufacture and has low resistance.
The air duct with a larger diameter of the chip or format muffler increases the contact area between the sound-absorbing material and the sound wave, and reduces the "through" of mid- and high-frequency noise to ensure the muffling effect.
The resistant muffler, also known as the expansion muffler, is formed by connecting a tube and a small chamber, and uses the sudden change in the section of the duct to reflect noise. The structure is simple, no sound-absorbing material is used, so it is not affected by high temperature and corrosive gas.
Resistant muffler has a good silencing effect on low frequency and intermediate frequency noise, and is mainly used to eliminate low frequency and low intermediate frequency noise.
The resonance muffler uses a pipe opening to communicate with the resonant cavity. The perforation and the air in the cavity form an elastic resonance system. When the external noise is at the same frequency, it resonates, and the perforation rubs against the hole wall to consume sound energy.