Product Description
The silencer ((Muffler)) is a device designed and produced by Changsha de Jie Electromechanical Technology Co., Ltd. to prevent sound transmission and allow air flow to pass through. It is an important measure to eliminate aerodynamic noise. The muffler (patent number: ZL201420804814.6) is a device for reducing noise in the air passage of the air power equipment (such as air blower, air compressor, boiler exhaust port, generator, water pump and so on), or in the inlet and exhaust systems. There are many kinds of silencers, but they are divided into six main types, namely, resistive silencer, resistant muffler, impedance compound silencer, microperforated board silencer, small hole muffler and active muffler.
Damping silencer
Noise reduction is mainly achieved by using porous sound absorbing materials. A sound silencer is formed by fixing sound absorbing material on the inner wall of the airflow channel or arranging it in a certain way in the pipeline. When sound waves enter a resistive silencer, part of the acoustic energy is frictional in the pores of porous materials and dissipates into thermal energy dissipation, resulting in the attenuation of sound waves through silencers. A resistive silencer is like a pure resistance circuit in electricity. Sound absorbing material is similar to resistance. Therefore, people call this muffler a resistive muffler. The resistive muffler has good effect on medium and high frequency noise elimination, and low noise attenuation effect. (mainly used for generator silencing)
The resistant muffler is composed of the tube and chamber of the abrupt interface. It is like an acoustic filter, similar to the electrical filter. Each tube with a tube is a mesh of the filter. The air quality in the tube is equivalent to the electrical inductance and resistance, called the sound mass and the acoustic resistance. The volume of air in the chamber is equivalent to the electrical capacitance, which is called sound compliance. Similar to the electrical filter, each tube chamber has its own natural frequency. When the sound waves containing various frequency components enter the first short tube, only the sound waves at some frequencies near the natural frequency of the first mesh can reach second short tubes through the mesh holes, while some other frequencies are not possible to pass through the mesh. The structure of the wave has the filter function as the acoustic filter. The proper combination of tube and chamber can filter out some frequency components and achieve the purpose of noise elimination. The resistance muffler is suitable for eliminating medium and low frequency noise. The resistive composite muffler is made by combining resistive structure and resistance structure in a certain way. Micro perforated plate silencer
It is usually made of pure metal sheet and perforated with a bit smaller than 1mm on the sheet. The perforation rate is 1% 1 3%. The spectrum performance of the muffler can be controlled by selecting the different perforation rate and the depth of the cavity with different thickness of the plate, so that it can get a good silencing effect in the required frequency range. The structure of the small hole muffler is a straight pipe closed at the end, and many small holes are drilled on the wall. The principle of the small hole muffler is based on the spectrum of jet noise. If the total area of the nozzle is kept constant and replaced by a lot of small nozzle, the frequency spectrum of the jet noise will move to high frequency or UHF when the air flow passes through the hole, so that the audible components in the spectrum can be reduced obviously, thus reducing the interference and damage to the people.
The basic principle of the active muffler is that in the original sound field, an electronic device is used to produce a sound wave that is equal to the original sound pressure and the phase is opposite, so that the sound field is counterbalanced against the original sound field in a certain range. The muffler is a set of instruments, mainly composed of microphone, amplifier, phase shifter, power amplifier and loudspeaker. The new high efficiency anti spray resistance type silencer equipment can be widely used in power, chemical, metallurgical, textile and other industrial factories and mines for various types of boiler, steam turbine exhaust, fan, safety door and other equipment. This series of silencers are developed according to the principle of anti, spray and resistance compound silencing. It has many advantages, such as large amount of silencing, small volume, light weight, easy to install and easy to install. The muffling frequency characteristic of the muffler. The anti surge muffler is superior to all frequency noise. The applicable wind speed of mufflers is generally 6-8m/s, the highest should not exceed 12m/s, while the pressure loss of silencers should be noted. Pay attention to the cross section of the net channel of the muffler. When necessary, the wind duct and the muffler must be amplified when necessary.
• installation of silencers such as mufflers must have independent bearing hangers or pedestal, and sound source devices must be connected through flexible joints. When two silencers are used in series, the connection distance between the two elbows should be 2.5 times higher than the diagonal length of the elbow section. For the environment system with high temperature, high humidity, oil mist and water gas, microporous structure silencing equipment is used generally, and microporous structure silencing equipment should be used for the environmental system such as operation room, recording room, clean factory and so on. When the adjacent rooms are connected, attention should be paid to the mutual influence of indoor noise through pipelines, and the muffler should be treated if necessary.