1、 Function of muffler.

Automobile muffler is an effective equipment to control the outward propagation of aerodynamic noise. After internal acoustic treatment, the generation and propagation of noise can be greatly reduced without affecting the passage of air flow. After the silencer is installed on the equipment, the silencing amount shall reach 20-40db (a), and the subjective perceived loudness shall be reduced by 50-90%.

2、 Types of automobile silencers.

 Resistive automobile muffler has the characteristics of absorbing medium and high frequency sound and simple processing and manufacturing. It is generally used for noise elimination of air conditioning fans, compressors, gas turbines, blowers and other fans.

The resistant muffler has the characteristics of strong pertinence, significant medium and low frequency sound absorption effect and no sound-absorbing material. Generally, it can only be used for exhaust silencing of small pipes, such as automobiles, ships, diesel engines, etc.

Impedance muffler has the characteristics of silencing bandwidth and safe use. It is mainly used for silencing if broadband noise with high sound level but low frequency. Such as steam turbine, deaerator, flash tank, small displacement safety valve, etc.

The small hole muffler has low medium frequency and broadband silencing performance. Small aperture can improve the sound absorption coefficient, low porosity can increase the width of sound absorption band, and the depth of orifice plate can change the position of resonance sound absorption peak. Small hole muffler has the advantages of tight design, wide absorption frequency band, small resistance loss, high temperature resistance, long service life and so on. It is generally used for exhaust of boilers, compressors and other high-pressure equipment.

The anti jet resistance composite muffler has the advantages of wide silencing bandwidth, wide application range, large silencing volume, high temperature and high pressure resistance, and is not afraid of water vapor and oil mist. It was successfully developed on the basis of the small hole injection silencing theory of Chinese acoustician Ma Daxian. It is also the structural exhaust muffler in China at present, and various power plants are generally selected.

The through-hole dissipative muffler has the advantages of smooth exhaust, high temperature resistance and strong anti-interference. It is generally used for exhaust and silencing of safety valve, exhaust valve, steam turbine and blowpipe.

3、 Evaluation of muffler.

There are two aspects to evaluate the performance of muffler: one is aerodynamic performance, the other is silencing performance. In other words, the pressure loss of the muffler must be within the allowable limit and meet the requirements of the noise standard. Therefore, aerodynamic performance and silencing performance should be considered when purchasing muffler, both of which are indispensable.

4、 Selection of muffler.

When purchasing fan silencer, the user shall submit the fan type (including blower, ventilator, roots blower, axial flow fan, air compressor, etc.), And provide the inlet and outlet size and air volume of the fan. Generally, the fan muffler is installed at the outlet, and the fan muffler shall be treated comprehensively, that is, the muffler and sound insulation room shall be installed together. The shell of the fan muffler is carbon steel, and the internal material is divided into aluminum plate and stainless steel, which can be selected by the user according to the cost.

When purchasing the boiler steam exhaust muffler, the user shall provide the hourly emission, exhaust outlet size, exhaust temperature and pressure. The exhaust muffler generally adopts the anti spray resistance composite automobile muffler. Generally, the shell is carbon steel, and the connecting pipe and internal material are stainless steel. It has the advantages of silencing bandwidth, wide application range, large silencing volume, high temperature and high pressure resistance, and is not afraid of water vapor and oil mist. Small hole jet muffler can also be used, which is generally all stainless steel.

The pipe blowing muffler must be suitable for harsh working environment. The working medium can contain water, iron sundries (particle size up to 30mm), engineering residues, etc. The user shall provide the emission, exhaust outlet size, exhaust temperature and unit model. The blowpipe muffler generally adopts through-hole dissipative muffler. Generally, the connecting pipe and shell are carbon steel, and the internal material is stainless steel. It is generally disposable, and can also be designed many times according to the user's requirements. In addition, we can recycle after use.

Function, type and selection of automobile muffler.

4. The steam exhaust of safety valve is an instantaneous sudden discharge. When designing the safety valve silencer, it shall be considered that the discharge is unblocked without throttling. The user shall provide safety valve discharge, exhaust outlet size, exhaust temperature and take-off pressure. The exhaust muffler of safety valve generally adopts through-hole dissipative muffler, the shell is generally carbon steel, and the connecting pipe and internal material are stainless steel. Small hole injection muffler can also be used, provided that the emission must be large enough to avoid stuffy pressure and throttling. It is generally made of all stainless steel.