狼人就干网_亚州日韩视频_性交A片无码欧美_免费看黄AV

Product introduction

Fan muffler, and exhaust pipe muffler and drum induced draft fan muffler in the same form, adopts the resistance sound absorption and noise reduction principle for medium and high frequency broadband characteristics have a good effect, the resistance sound reduction principle for low and medium frequency and pulsation characteristics have a good effect, as well as micro-perforated muffler and impedance compound muffler. Resistance muffler is a production of absorption type muffler, according to the airflow channel structure is different, generally divided into straight pipe type, plate type, folding plate, honeycomb, acoustic flow, labyrinth type and elbow type. Resistive muffler is the use of sound waves in the propagation of porous sound absorbing materials, friction and viscous resistance, the sound energy into heat energy dissipation, so as to achieve the purpose of sound reduction.