Let's take a look at the formation of ceiling fan noise
1. System impedance. The range between the air inlet and the air outlet of a shell accounts for 60% to 80% of the total system impedance. In addition, the larger the air flow is, the higher the noise is. The higher the system impedance, the greater the air flow required for cooling. Therefore, in order to reduce the noise, the system impedance must be reduced to a relatively low level.
2. Air turbulence. Noise is generated by turbulence caused by obstructions along the airflow path. Therefore, any obstruction, especially in the critical air inlet and outlet range, must be avoided to reduce noise.
3. Fan speed and size. As the high-speed fan produces more noise than the low-speed fan, the low-speed fan should be tried and selected as far as possible. However, a fan with larger size and lower speed is usually quieter than a fan with smaller size and higher speed when conveying the same air volume.
4. Voltage variation. Voltage variation will affect the noise level. The higher the voltage applied to the fan, the greater the vibration and the greater the noise due to the increase of the speed. The design consideration of each part of the fan will affect the noise level. When designing, we should consider the size of the winding core, the design of the fan blade and the outer frame, and the accurate manufacture and balance to achieve the purpose of reducing noise.
Industrial ceiling fan
Noise treatment of industrial ceiling fan
1. Solutions to wind noise
(1) The linear velocity of blade tip is limited to reduce noise. Generally speaking, blade aerodynamic noise is proportional to the 5th power of blade tip linear velocity. In blade design, the relationship between blade length and speed should be coordinated. For the mature type of blade, if necessary, it can reduce the speed to achieve the purpose of noise reduction, but generally it will lose a certain amount of air.
(2) Change the blade shape chord length to design noise reduction. In the design of a blade, the chord length of the blade root section can be appropriately reduced without affecting other performance. On the other hand, the noise produced by the fan blade often increases with the increase of the blade tip chord. In order to reduce the noise, the blade tip chord length can also be reduced moderately. In order to ensure that the power does not drop, moderately increase the blade area from the middle to the rear.
2. Vibration solutions
The way to solve the vibration is to install and fix the fan. High speed rotation will produce a certain force, which will cause the blade to loosen and make the blade and bearing produce a large gap due to friction, so as to produce vibration noise during operation. In case of such noise, the fan blade of large industrial fan should be removed first, and then the fan blade should be installed after the screw is tightened, so as to avoid the gap between the blade and the bearing, so that it will not make vibration noise when the fan is rotating.
3. Solution to abnormal sound of ceiling fan
(1) Clean up regularly. Cleaning is not only the shallow cleaning of fan blades, but also the cleaning of bearings. Under the condition of not damaging the bearings and fans, they should be cleaned to avoid accumulation of impurities, which will burden the operation of fans.
(2) Check in time. Check the shape and working state of each component in time. If any problem is found, it should be adjusted in time. If it needs to be replaced, it should be replaced in time. For example, if the bearing is deformed, it needs to be replaced immediately to avoid affecting the normal use of the fan.
(3) Do a good job of lubrication. Bearing is one of the most important operating parts of large industrial fans. After a long time of use, there will be a lack of lubricating oil. Therefore, when a large industrial fan with reasonable price runs at high speed, it will produce a greater noise. In this case, a few drops of lubricating oil can be applied to the bearings of large industrial fans. If not, it can be replaced by sewing machine oil, but not edible oil.