How to reduce the noise of cooling tower?

During the operation of closed cooling tower, the noise of closed cooling tower has a great influence because of the non-stop operation of water pump, fan and circulating water. Noise is mainly caused by vibration, and the noise of closed cooling tower mainly includes several aspects: water spraying sound, fan wind noise and pump vibration sound. The noise and vibration of the closed cooling tower have a large influence range, which can be designed within the range of 30-50 meters around, and then return to 60-70 decibels after adding anechoic tiles and sound barriers. Therefore, the noise impact of closed cooling tower is more serious. The main methods to solve the noise are: blocking noise transmission, increasing sound insulation cotton, replacing low-speed fans and so on.

1. Noise reduction principle of closed cooling tower;

The noise of closed cooling tower mainly spreads through air, buildings and the earth, and air is the main way. The noise reduction principle of cooling tower is to block the propagation path of sound waves and add a sound barrier around the cooling tower. When the sound meets an obstacle, it will be reflected. The greater the reflection distance, the sound will gradually weaken, and the decibel of the sound will decrease after repeated refraction. Because the frequency wave of water noise is different from that of fans and pumps, it is best to set a barrier in the noise area of cooling tower near it.

2. Selection of noise reduction barrier for cooling tower:

The barrier required for noise reduction of closed cooling tower should be used according to the situation. Brick walls, glass fiber reinforced plastics and aluminum alloys are more common. Brick wall is designed with sand surface, which has more surface noise and can reflect sounds from different angles. The service life of brick wall is very reliable. Aluminum alloy and glass fiber reinforced plastic have smooth surfaces, so a certain arc surface should be designed. Reflect the sound downward to the maximum extent. Floating falling water energy dissipation and noise reduction device is mainly made of plastic parts or FRP parts (stressed parts) by extrusion, injection molding or hot pressing. Its material features light structure, easy handling, easy installation, corrosion resistance and durability.

3. Noise reduction skills of fans and pumps:

Fans and pumps are also the main places to produce noise. The high-speed rotating fan makes a lot of wind noise. If you only deal with the noise of the fan, you can increase the air volume and reduce the speed. Increasing the air volume can increase the camber angle of the fan. If the budget is sufficient, you can consider directly replacing the low-speed fan with large blades to reduce noise. Or install a noise elimination net at the air outlet of the water pump and fan, and the noise reduction range of the noise elimination net is 20-30 decibels. The water pump can be designed with sound insulation cotton outside the water pump, which can effectively reduce the noise and will not affect the heat dissipation of the water pump.

If the closed cooling tower is designed outdoors, the above methods are mainly used to reduce noise. If the cooling tower is designed indoors, the indoor design can be soundproof. Interior design, you can use sound insulation paint.

In the process of noise reduction of closed cooling tower, the ventilation and heat dissipation of cooling tower should be considered, and the designed sound barrier and sound insulation cotton can not affect the ventilation of cooling tower. The main transmission way of water spray sound of closed cooling tower is also through the fan of fan. The cross-flow cooling tower has only one air inlet, and there will be an air inlet grille around the bottom of the counter-flow cooling tower. The sound of water spray forms convection with the air inlet, which will reduce the noise propagation.