Impedance type muffler

Impedance muffler is a necessary accessory for air supply systems to reduce dynamic pressure, increase static pressure, stabilize airflow, and reduce airflow vibration. It can make the air supply effect more ideal. 1. Resistive muffler: It absorbs sound energy and reduces noise by attaching sound-absorbing materials inside the box, usually used to eliminate high and medium frequency noise. However, due to structural reasons, it is not suitable for high temperature, high humidity, and high speed situations. 2. Anti type muffler: It reduces noise by changing the cross-section. The commonly used soundproof static pressure box is based on this principle. Generally reduce mid to low frequency noise. There are no specific requirements for the wind system. 3. Impedance composite: Of course, it combines the structural principles of both. It can eliminate low, medium, and high frequency noise. However, for general civil air conditioning and ventilation systems, I personally think it is better to choose impedance composite mufflers, as the requirements for the wind system are the same as those for resistive mufflers. The resistive muffler has good mid to high frequency noise reduction performance. According to the geometric shape of the airflow channel, it can be divided into straight pipe type, sheet type, folded plate type, maze type, honeycomb type, acoustic flow type, baffle type, elbow type, etc. Resistance mufflers are suitable for eliminating mid to low frequency noise or narrowband noise. According to their different operating principles, they can be divided into various types such as expansion type, resonant cavity type, and interference type. Impedance composite muffler has acoustic filtering devices such as resonant cavity, expansion chamber, perforated screen, etc. It combines the good high-frequency noise reduction characteristics of resistive muffler and the good low-frequency noise reduction characteristics of resistive muffler. Therefore, its noise reduction frequency band is wide, and it is one of the most commonly used standard muffler series. The suitable wind speed is 6-8 meters per second, which can reach 8-12 meters. It can be used alone or in series. Noise reduction effect: Low frequency of 10-15 dB/m, medium frequency of 15-25 dB/m, high frequency of 25-30 dB/m, with an average drag coefficient of 0.4. According to "Air Conditioning", soundproof elbows and soundproof static pressure boxes are both types of mufflers. The function of a static pressure box is to convert some dynamic pressure into static pressure, allowing the wind to blow further; 2. Can reduce noise 3, evenly distribute air volume