Rotary Blower Mufflers/Acoustic Silencers are designed based on the sound absorption principle of sound-absorbing panels. This type of silencer boasts excellent acoustic performance and good aerodynamic performance; the structure is reasonable and easy to install, making it a high-airflow resistive honeycomb silencer. The resistive section employs multi-chamber resistive straight tube channels and cross-shaped sound-absorbing panels, ensuring sufficient noise reduction across a wide frequency range. The silencer structure is composed of many parallel unit silencer tubes filled with porous sound-absorbing material. To reduce radiation noise caused by airflow-induced shell wall vibration, reinforcing ribs are set on the outer shell. The forms of mufflers for fans include centrifugal fan mufflers, Roots blower mufflers, exhaust fan mufflers, and axial flow fan mufflers. Fan mufflers are mainly used to reduce aerodynamic noise at various fan inlets, ducts, and enclosed machine room air intake ports. 1. According to the structure of fan inlet and outlet, they are divided into circular and rectangular structures. 1): The circular structure is used for fan connection ports that are circular, and it is divided into two types, A and B. Type A has flanges at both ends and is directly connected to the pipeline (i.e., pipeline silencer), while Type B has a flange at one end and a direct atmospheric exhaust at the other (can be equipped with a rainproof wind cap), suitable only for outdoor pipeline ends and enclosed machine room air intake ports. 2) The resistive sound-absorbing panels in the circular structure generally have a thickness of 100mm or 150mm, with a noise reduction of 15-30dB(A). Under wind speeds of 5-12m/s, they are applicable for air volumes of 1000-50000m³/h. The structure uses two types of acoustic zones, impedance, for noise reduction of both high and low frequencies, to maximize the broadening of the noise reduction frequency band.