Cooling tower noise sources and noise reduction methods
Author：Trlon Views: Time:2020-10-19
Everyone should know that the propagation of sound requires a vibration step, so that the formation of cooling tower noise is the same. With many years of experience in manufacturing and product research and development of trlon, we have summarized some sources of cooling tower noise. The noise sources of cooling towers in operation are mainly: water splashing, fan noise, and water pump vibration. The interference area of the cooling tower noise co-shock is particularly large, which can affect the surrounding area within 30-50 meters. After adding the silencing tile and noise barrier, it will return to 60-70dB. Therefore, the noise interference of the cooling tower is more serious. The main methods of dealing with noise are: blocking noise spreading, improving sound-absorbing cotton, and changing low-speed fans.
Cooling tower noise reduction treatment method
The basic principle of cooling tower noise reduction treatment
The noise dissemination of cooling towers is mainly spread by three types of methods: gas, building bodies, and ground, which are mainly spread by air. The basic principle of noise reduction processing of cooling towers is to block the propagation path of sound insulation waves. Increase the sound barrier around the cooling tower. When the sound hits the barrier, the sound will scatter. The larger the scattering distance, the sound will gradually change. Weak, the decibel of the sound will be reduced after several times of refraction. Since water noise is different from the noise frequency waves formed by the sound of fans and pumps, it is best to set the barrier in the noise area of the cooling tower to be close to the cooling tower.
Selection of barriers for cooling tower noise reduction treatment
The barriers required for cooling tower noise reduction treatment need to be applied according to specific conditions. The more common ones are wall tiles, fiberglass and aluminum alloys. The wall tiles are affected by the sand surface, and there are more surface noises, which can diffuse sound in various directions, and the service life of the wall tiles is particularly reliable. The surface of aluminum alloy and FRP is relatively smooth, so the corresponding curved surface needs to be affected. Scatter the sound downward at a louder level. Floating type falling into the water energy dissipation and noise reduction treatment equipment is mainly composed of plastic parts or glass steel parts (forced parts) that are formed by extrusion, injection molding or hot pressing. Its material characteristics are light structure, easy to handle, easy to install, anti-corrosion and durable.
Noise reduction treatment methods for fans and water pumps
Fans and pumps are also key locations for noise. The wind noise from the fast-running fan is very loud. If it is only to deal with the noise of the fan, it can be done by increasing the exhaust air volume and reducing the speed ratio. Increasing the exhaust air volume can expand the curved surface of the fan. If the cost budget is relatively sufficient, it can be considered to immediately change the fan with large blades and low speed ratio to reduce noise. Or assemble a noise reduction screen at the air outlet of the water pump and fan, and the noise reduction treatment area of the noise reduction screen is 20-30 decibels. The water pump can be made of sound-absorbing cotton outside the pump. The sound-absorbing cotton can reduce noise very reasonably, and it is not easy to harm the heat exhaust of the water pump.
Cooling tower noise index
If the cooling tower is designed outdoors, the key is the above method to carry out noise reduction treatment. If the cooling tower is designed indoors, the interior design can be soundproofed. If it is formulated indoors, noise-reducing coatings can be used.
In the process of formulating the noise reduction treatment of the cooling tower, the natural ventilation heat rejection condition of the cooling tower should be considered, and the sound insulation barriers and sound-absorbing cotton formulated shall not harm the natural ventilation volume of the cooling tower. The key transmission path of the water splashing sound of the cooling tower is also through the fan of the fan. The cross-flow cooling tower has only one air inlet, and the bottom of the counter-flow cooling tower is surrounded by an air inlet grille. The inlet air from the tuyere generates heat convection, which will reduce the spread of noise.