Noise control of ball mill

1、 The source of noise from the ball mill

(1) The noise generated by the cylinder is mechanical noise generated by the collision between steel balls and between steel balls and the steel cylinder when the cylinder rotates. The noise level radiated outward through the cylinder can reach 115dBA or more, and the noise frequency band is wide.

(2) Noise generated by motors and transmission machinery, electromagnetic noise generated by motor operation, airflow noise generated by fans, etc. The motor noise is directly proportional to the motor power and speed, and its noise level is generally between 90dBA and 115dBA. The noise of transmission machinery is mainly caused by the collision between gears and the friction between components.

2、 Methods for noise control of ball mills

(1) The damping and sound insulation layer is wrapped around the cylinder of the ball mill with insulation material, thereby reducing the noise of the cylinder. This method can generally reduce 5-10dBA, but the effect is not ideal.

(2) The soundproof cover is used to enclose the cylinder part of the ball mill, blocking the external transmission path of noise and reducing the radiation noise of the cylinder. This method is quite effective, and the noise reduction value can usually reach around 20dBA. But after installing the soundproof cover, maintenance and operation work become difficult. At the same time, due to the motor and transmission machinery being enclosed in soundproof enclosures, ventilation and heat dissipation of the equipment are difficult, and inspection and maintenance work are also very inconvenient. A soundproof enclosure is a device that controls noise along the path of sound propagation. The soundproof enclosure shell is made of thin gold plate, and the inner wall is coated with viscous material with high friction damping. The middle is decorated with sound-absorbing material with a sound absorption coefficient α higher than 0.6, leaving enough air layer, and the inner surface is decorated with perforated panels, etc. advantage:

1. The soundproof enclosure has a small volume and can be designed according to user needs;

2. The soundproof cover is detachable, easy to install and maintain on site;   

3. The soundproof cover adopts advanced soundproof materials, which can reduce noise by 15-30dB (A)

4. Soundproof enclosures beautify the environment and improve the level of civilized production.
(3) Replacing manganese steel lining with rubber lining in the cylinder body can greatly reduce the impact noise between steel balls and the cylinder body, with a noise reduction value of 12-15dBA. The effect is significant, but there are still issues with the service life of rubber lining.
 

Previous article: Fan silencer
Next article: Pump room noise control