When we use large-scale HVLS industrial fans, we will encounter noise problems. So, how to control the noise of large-scale HVLS industrial fans? What are the methods? Let's take a look together.
1. Change the tip vortex of large HVLS industrial fans
The tip vortex is one of the main sources of aerodynamic noise of large HVLS industrial fan blades. Installing "small wings" and "flaps" at the tips of the blades is a more feasible noise reduction method. The tip "winglets" can suppress the generation of turbulence and vortices. The flaps can capture and guide the vortex airflow by optimizing the shape and installation angle, weaken the strength of the vortex, improve the aerodynamic performance of the blade, and reduce operating noise.
2. Damping and shock absorption of large HVLS industrial fans
Damping vibration and noise reduction technology uses the characteristics of damping materials and the reasonable design of damping structures to dissipate the vibration energy of structural parts to achieve the purpose of vibration and noise reduction.
Most of the blades of large industrial fans for warehouses adopt hollow thin-walled structures, which can perform some and all free damping treatments in the shell from the rear end to the tip part of the blade with relatively severe vibration, such as filling and attaching damping materials and passing vibration waves. The interaction of damping materials or damping structures consumes energy, which attenuates blade vibration and reduces noise.
3. Change the shape and chord length design of large HVLS industrial fan blades
In a blade design, the chord length of the blade root section can be appropriately reduced without affecting other performance. On the other hand, the noise produced by large industrial fan blades tends to increase with the increase of the blade tip chord. In order to reduce the noise, the blade tip chord length can also be appropriately reduced. In order to ensure that the power does not drop, moderately enlarge the blade from the middle to the middle rear area.
4. Limit the linear speed of the blade tip of large HVLS industrial fans
Generally speaking, the blade aerodynamic noise is proportional to the 5th power of the blade tip linear velocity. When designing blades, the relationship between blade length and speed must be coordinated. For mature models of blades, if necessary, you can also reduce the speed of the HVLS industrial fan to achieve the purpose of noise reduction, but generally, a certain amount of air volume will be lost.
5. Do a good job in the lubrication of large HVLS industrial fan bearings
Bearings are a major operating component of large HVLS industrial fans. After a long time of use, they will lack lubricating oil. Therefore, when a reasonably priced HVLS industrial fan runs at a high speed, it will produce greater noise.
In this case, you can put a few drops of lubricating oil on the bearing of the large HVLS industrial fan. If not, you can replace it with sewing machine oil, but it cannot be replaced with edible oil.
6. Fix the blades of large HVLS industrial fans
High-speed rotation will generate a certain force, which will cause the blades to loosen and cause a large gap between the blades and the bearing due to friction, which will cause vibration and noise during operation. In the case of noise in this situation, you should first remove the fan blades of the HVLS industrial fan, tighten the screws and then install the fan blades to avoid gaps between the blades and the bearings, so that they will not be allowed to rotate in the fan Vibrating noise is made at the time.
7. Polishing the blades of large HVLS industrial fans
If the center of gravity of the blade of a large industrial fan is not above the axis, it will form an eccentric phenomenon, which will not only produce a lot of noise but also may damage the core components of the fan.
Therefore, the fan blades should be removed, and then a thin wire should be hung at its center position. After it is still, see which side it sinks to, and lightly grind the sinking end on the grinding wheel a few times before testing. Just wait until the large HVLS industrial fan can be in a horizontal position before installing it.
The above is the whole content of the noise control method of the HVLS industrial fan that we have summarized for everyone. It can be seen that this way can we ensure that the HVLS industrial fan solves our damp heat, ventilation, and other problems when the noise is relatively small, and our company strives to achieve the large-scale HVLS The noise of industrial fans is reduced to a relatively low level. If you need it, you can call us at any time.
Source: Gaxiaofan Press Department
Publication Date: 6/1/2021
