The structure and principle of the negative pressure intake muffler for Roots blower are introduced as follows:
1、 Structure
The Roots blower negative pressure intake muffler is a high air volume resistive honeycomb muffler with a reasonable structure and easy installation. Specifically, it is composed of many parallel unit sound-absorbing tubes arranged with porous sound-absorbing materials filled between them. In order to reduce the radiated sound caused by the vibration of the airflow shell wall, reinforcement ribs are installed on the outer shell of the muffler.
In addition, according to the different inlet and outlet structures of the fan, Roots blower silencers can be divided into circular and rectangular structures. The circular structure is mainly used for situations where the connecting port of the fan is circular, and can be divided into two types: Type A and Type B. Type A has flanges at both ends, which can be directly connected in series to the pipeline and used as a pipeline muffler; Type B has a flange on one end and a direct atmospheric vent on the other end (which can be equipped with a rainproof hood), suitable for installation at the end of outdoor pipelines and enclosed machine room air intakes.
2、 Principle
The negative pressure intake muffler of Roots blower is developed based on the principle of sound blocking plate noise reduction. It has excellent acoustic performance and good aerodynamic performance. Inside the muffler, the impedance composite noise reduction principle is adopted, which includes the resistive sound absorption and noise reduction principle that has good effects on medium and high frequency broadband characteristics, as well as the resistant noise reduction principle that has good effects on low, medium frequency, and pulsation characteristics.
Specifically, the resistive sound-absorbing plate in the muffler adopts two types of impedance sound-absorbing zones for high-frequency and low-frequency noise reduction. The resistive structure mainly plays a role in absorbing and reducing high and medium frequency noise, while the resistive structure plays a role in reducing and eliminating medium and low frequency noise. At the same time, two types of sound-absorbing and silencing zones, high frequency and low frequency, are also used in the resistive channel to maximize the silencing frequency band and achieve good denoising effect.
In addition, the noise source of the fan often has more than one spectral value at the noise level, and the requirements for its noise reduction vary for different spectral bands. Therefore, the installation of Roots blower silencers requires actual testing based on the noise sources at the fan operation site to determine the required amount of noise reduction in which frequency ranges, and serves as the main basis for designing sound absorbers and fluid channels.
In general, the negative pressure intake muffler of Roots blower can effectively reduce the noise generated during the intake process of Roots blower through its structure and principle, providing guarantee for the stable operation of equipment and the quietness of the surrounding environment.
