Roots FansIn the process of using the excessive noise, then how to reduce the noise of Roots fan? Roots fan editorial take you to understand.
1. Reduce the noise of the sound source
The most fundamental way to control fan noise is to make the noise of the source lower.
(1) Reduce the excitation force of the sound source
a. Reduce the impact and eddy current noise generated by aerodynamic forces. As the fan noise and impeller circumferential speed of 6 times proportional to the relationship, so it is necessary to reasonably select the fan noise impact, the gap is too small, the noise will increase faster.
b. Improve the dynamic balancing accuracy of the impeller and the rotating shaft to reduce the noise generated by the unbalanced weight. If the fan adopts variable speed drive, the dynamic balancing accuracy of its gears and couplings should also be strictly corrected.
c. Maintain good lubrication conditions to reduce the excitation force of the sound source.
(2) Reduction of the response of noise radiating components in the system to excitation forces
a. Changing the intrinsic frequency of a resonant member
b. Adoption of excellent damping materials to reduce the radiation of noise.
c. Use of silencers.
For ventilators, due to their wider noise band and small allowable pressure loss, expansion and resonance mufflers are generally seldom used, and more sound-absorbing mufflers are used to reduce the noise of the fan.
(3) Correct installation and use, proper installation, reasonable use and maintenance of the equipment to prevent the fan from producing abnormal sounds during operation.
2. Noise control of the transmission path
The following methods can be used to achieve noise control in the conveying path of the fan intake and exhaust.
(1) Sound insulation of the sound source, the use of properly designed acoustic enclosure around the noise source, so that the sound source is closed, to prevent or reduce the propagation of the noise source to the outside. In order to prevent or reduce the spread of noise, the fan can also be installed in the sound-absorbing performance of the sound insulation room, and at the same time in the air inlet set muffler, so that the noise attenuation.
(2) sound absorption, that is, the use of sound absorption principle, the use of good sound-absorbing materials, so that the noise in the transmission, constantly being attenuated. Can also be set in the fan pipe outlet sound-absorbing plate, so that the noise level is effectively reduced. This sound-absorbing plate can also be installed in the inlet side of the fan, but also to get a good muffling effect.
(3) sound reflection, that is, the use of sound reflection principle, the use of non-connected structure, so that the sound energy reflected to the sound source, the so-called impedance mismatch, blocking the propagation of noise.