Introduction to the classification of muffler
In the machinery industry, the normal operation of machinery will produce a lot of noise. In order to create a more user-friendly working environment, mufflers have come into being. What types of mufflers are there? Today we will share the relevant basic knowledge for your reference. Types of muffler:
There are many types of mufflers, but according to different muffler principles, there are resistive mufflers, resistive mufflers and impedance composite mufflers.
(1) Resistive muffler
It uses the porous sound-absorbing material on the inner surface of the air flow channel to absorb sound energy. Its structure is simple, and it can muffle the sound in a wide high frequency range, especially for the harsh high-frequency sound waves, but has a poor muffling effect for low-frequency noise.
(2) Resistant muffler
It uses the acoustic characteristics of the pipeline to prevent sound waves from propagating and penetrating along the pipeline at the mutation interface of the pipeline or bypassing the resonant cavity, so as to achieve the purpose of noise reduction. It can well eliminate low-frequency noise, and can work under high temperature and high-speed pulsed airflow. It is suitable for muffler of exhaust pipes of automobiles and tractors. The resistant muffler includes expansion chamber muffler, resonance muffler and interference muffler.
(3) Impedance compound muffler
It is a combination of resistive muffler and resistive muffler. Commonly used are diffusion chamber impedance composite muffler, resonant cavity resistive composite muffler and diffusion chamber-resonant cavity-resistive composite muffler, so that it can be in a wide frequency range Obtain a good noise reduction effect.
(4) Micro-perforated plate muffler:
It is made of thin metal plate, which is a kind of impedance composite muffler, which can have good noise elimination effect in a wide frequency range. The micro-perforated board has low impedance, high temperature resistance, and is not afraid of oil and water vapor. The hole diameter of the metal sheet is less than 1mm, and the perforation rate is 1%~3%. Similarly, the micro-perforated plate muffler can be combined with porous sound-absorbing materials and expansion chambers to form various forms of micro-perforated composite muffler.
(5) Porous diffusion muffler
It is often installed on the exhaust port of the pneumatic directional control valve to eliminate the noise of high-speed jet jets. When multiple valves are exhausted and silenced, the method of centralized exhaust silence is also useful. A structure in which the muffler material is sintered with copper particles, and the design of sintered plastic particles also requires that the effective outflow area of the muffler is greater than the effective area of the exhaust pipe. This type of muffler is widely used in pneumatic systems.