The ball mill is indispensable grinding equipment in the ore beneficiation process. How to control the ball mill noise?
Ball mill is mainly used for grinding materials in the industrial production process. Due to the large volume and heavy tonnage, the noise ( strong vibration and noise ) generated is usually above 95dB(A), which is serious affects the physical and mental health of workers.
Cause of noise
The ball mill noise is mainly caused by the mechanical noise generated by the collision between the grinding ball in the drum and the wall liner and the material to be processed.
The noise radiates outward along the lining, the wall of the cylinder, and the inlet and outlet ports, noise source including: the impact sound between the steel ball and the steel ball, the impact of the steel ball and the inner lining steel plate, the impact of the material, and the friction sound.
The ball mill noise is related to the diameter of the ball mill, the speed of the ball, and the nature and blockiness of the material. The ball mill noise is basically steady-state noise, wide frequency range, the larger the diameter, the stronger the low frequency noise.
Methods of reducing ball mill noise
Install gear correctly
In the ball mill installation process, the gear coincidence, gap and modulus should be controlled within a reasonable error range. Exceeding the error range will not only bring great noise, but also affect the ball mill operation.
Adding an acoustic enclosure or damping sound insulation layer to the outside of the ball mill barrel
The collision between the liner and the material and the grinding medium will make noise. Adding an acoustic enclosure outside the cylinder can reduce the noise, but the disadvantage is that it will affect the ventilation and heat dissipation, and it will also cause trouble for the later maintenance and maintenance.
The damped sound insulation layer avoids this kind of trouble. A floating clamp type damper sound insulation sleeve is arranged on the outer casing of the cylinder, and the cylinder is wrapped with a damped sound insulation layer to reduce noise by 12 to 15 dB (A).
Noise insulation materials for ball mills are currently available in the market for noise covers, noise enclosure and noiseproof screens.
- Noise cover
Structure: fixed and movable type.
Material: stainless steel, manganese steel, iron, etc.
Advantages: simple design, easy installation, good sound insulation.
Disadvantages: The large floor area is equivalent to placing the entire cement ball mill, reducer and motor under the cover. It is easy to accumulate powder and it is inconvenient to maintain.
- Noise enclosure
Structure: Multi-layer, wrapped in the outside of the cement ball mill barrel.
Material: heat resistant material.
Advantages: easy to install, noise reduction up to 15-25db, thermal insulation.
- Noiseproof screen
Structure: fixed and mobile type.
Material: Lightweight, porous sound absorption material.
Advantages: Special materials, and good isolation for low frequency and high noise.
- Noise cover
Replacing the manganese steel liner with a rubber liner can reduce the impact noise of the cylinder.
Install an elastic cushion between the inner wall of the cylinder and the lining
Adding an elastic cushion layer between the inner wall of the cylinder and the lining plate to reduce the vibration amplitude and reduce the noise radiation. This method can reduce the noise by about 10 dB(A).
Regular inspection of the lubrication system
Regularly check the lubrication system and regularly add lubricant to reduce the noise caused by the friction of the gear.
On the whole, there are two ways to reduce the noise of the ball mill: first, the sound transmission path; second, the source of the noise.
Reduce noise, create a better working environment, make the production of equipment more continuous and efficient, and bring greater profits to production.