Noise Control Technology Of Contra-rotating Axial Fan For Mine

The fan noise problem is one of the most popular and difficult issue within thefield of fan techniques. In this paper, a FBDNo6.3/2×30local mine fan wasstudied, theoretical analysis and the site experimental measurements and numericalsimulation analysis method was adopted to study the effect of the local fan noise ofabsorb controller and the barrel-shaped core of diffusion tube cone installed in thefan air intake design for noise reduction. The main contents include followingaspects:First of all, analysis the noise characteristics of the selected local fan, collatedthe main noise frequency range, the sound pressure amplitude data. Collection ofrelevant literature, study the main noise frequency range and spectral characteristicsof the air inlet and outlet.Second, the sound absorber was installed in the air intakes in the local fan,Virtual Lab Acoustics was used to simulate the control effect with and without theabsorber and with different absorber size, and change of sound pressure level wasdrawn before and after the installation of sound absorber. FLUENT software wasused to simulate the airflow resistance and the effect on the fan air volume and airpressure.Then, put forward a noise reduction design of local ventilator tube core. Changethe internal structure of the core barrel, use porous sound-absorbing materials andproduce small absorber in accordance with the principles of the muffler. Use theVirtual Lab Acoustics software to simulate the effect of noise reduction.This study show that: when absorber installed in the local fan air intake, thenoise of air intake can be controlled very well, the noise sound pressure leveldropped by an average of approximately10dB. Due to the smooth and streamlineddesign of absorber, the fan airflow resistance is smaller, about67Pa. The effect ofinstalled absorbers was less effect on the amount of wind of the fan air pressure. Thenoise reduction design for the diffusion tube effectively reduces the noise in the fanoutlet, the outlet sound pressure in the measurement point dropped by an average of 10.7dB. Through the noise reduction measures in the air inlet and outlet of the localfan, local fan noise was effectively reduced.